1 00:00:01,280 --> 00:00:04,279 Speaker 1: Welcome to Stuff You Missed in History Class, a production 2 00:00:04,360 --> 00:00:13,760 Speaker 1: of I Heart Radio. Hello, and welcome to the podcast. 3 00:00:13,800 --> 00:00:17,640 Speaker 1: I'm Tracy V. Wilson and I'm Holly Fry. I got 4 00:00:17,640 --> 00:00:22,440 Speaker 1: a physical the other day, always the most fun, so 5 00:00:22,520 --> 00:00:28,880 Speaker 1: much fun. My blood pressure was high. Not surprising really, 6 00:00:29,520 --> 00:00:33,159 Speaker 1: because number one, high blood pressure is just incredibly common. 7 00:00:33,240 --> 00:00:37,000 Speaker 1: It is the most prevalent non communicable chronic disease in 8 00:00:37,040 --> 00:00:40,879 Speaker 1: the world. But besides that, I'm forty seven and I 9 00:00:40,920 --> 00:00:43,680 Speaker 1: have hypertension on both sides of my family. So in 10 00:00:43,760 --> 00:00:46,560 Speaker 1: a lot of ways this has felt inevitable. So naturally, 11 00:00:47,280 --> 00:00:49,680 Speaker 1: as I have been taking my blood pressure at home, 12 00:00:49,800 --> 00:00:53,840 Speaker 1: as instructed by my doctor, I have been pondering how 13 00:00:53,960 --> 00:00:59,279 Speaker 1: humanity figured out that this often symptomless disease even exists. 14 00:01:01,520 --> 00:01:05,360 Speaker 1: Uh So, today's episode is about how we figured out 15 00:01:05,440 --> 00:01:09,199 Speaker 1: how to measure blood pressure and how hypertension became viewed 16 00:01:09,240 --> 00:01:12,759 Speaker 1: as a disease. Most of the detail goes up until 17 00:01:13,200 --> 00:01:17,440 Speaker 1: the first diuretics were developed, because that marked a big 18 00:01:17,480 --> 00:01:22,119 Speaker 1: shift in this and after that, so many things happened 19 00:01:22,160 --> 00:01:25,640 Speaker 1: so fast that it's was it felt impossible to include 20 00:01:25,640 --> 00:01:29,600 Speaker 1: them all. I did want to note that hypo tension 21 00:01:29,760 --> 00:01:33,240 Speaker 1: or low blood pressure that also exists. A lot of 22 00:01:33,240 --> 00:01:36,800 Speaker 1: people experience it as orthostatic hypotension, which is what happens 23 00:01:36,800 --> 00:01:38,480 Speaker 1: when you stand up too fast and you get that 24 00:01:38,560 --> 00:01:41,840 Speaker 1: lightheaded feeling. But a lot of people who have hypotension 25 00:01:42,000 --> 00:01:45,200 Speaker 1: for it's a lot more serious and really life disrupting. 26 00:01:45,760 --> 00:01:48,440 Speaker 1: But there's not as much historical focus on it because 27 00:01:48,480 --> 00:01:51,360 Speaker 1: a lot of the time it is connected to something 28 00:01:51,440 --> 00:01:55,600 Speaker 1: else rather than like a condition that's existing on its own. 29 00:01:56,240 --> 00:01:59,920 Speaker 1: Um also heads up. Obviously, we're gonna be talking a 30 00:02:00,000 --> 00:02:04,800 Speaker 1: out blood a lot, and some animal experimentation and some 31 00:02:04,800 --> 00:02:09,000 Speaker 1: stuff about restrictive dieting, and we don't normally give a 32 00:02:09,040 --> 00:02:13,280 Speaker 1: heads up about death on the show because death really 33 00:02:13,320 --> 00:02:16,440 Speaker 1: comes with the territory of a history podcast. It comes 34 00:02:16,520 --> 00:02:19,960 Speaker 1: up almost every episode. But there's a death in here 35 00:02:20,040 --> 00:02:22,640 Speaker 1: due to uncontrolled hypertension that I just found a little 36 00:02:22,720 --> 00:02:28,600 Speaker 1: unsettling to read, So just know that's coming later on. Yeah. So, 37 00:02:28,680 --> 00:02:31,960 Speaker 1: ancient cultures all over the world used the pulse as 38 00:02:32,000 --> 00:02:36,160 Speaker 1: a diagnostic tool. This is most documented in ancient Greek 39 00:02:36,200 --> 00:02:39,600 Speaker 1: medicine and in traditional Chinese medicine and ayur Veda, which 40 00:02:39,600 --> 00:02:43,119 Speaker 1: are still practiced today. It's also been part of indigenous 41 00:02:43,120 --> 00:02:46,760 Speaker 1: healing practices in other parts of the world. Many of 42 00:02:46,800 --> 00:02:50,200 Speaker 1: these traditional systems of medicine incorporate the idea of a 43 00:02:50,240 --> 00:02:54,240 Speaker 1: person's energy or life force or vitality and keeping that 44 00:02:54,360 --> 00:02:58,200 Speaker 1: energy balanced. So while a practitioner might be palpating a 45 00:02:58,240 --> 00:03:01,920 Speaker 1: person's physical pulse, they might be doing so to assess 46 00:03:02,040 --> 00:03:06,680 Speaker 1: something more metaphysical. The first written reference to something that 47 00:03:06,760 --> 00:03:10,000 Speaker 1: might have been high blood pressure maybe from the Chinese 48 00:03:10,120 --> 00:03:13,840 Speaker 1: Yellow Emperor's Classic of Internal Medicine that dates back to 49 00:03:13,880 --> 00:03:19,079 Speaker 1: about b c E. This text describes the pulse as 50 00:03:19,240 --> 00:03:22,040 Speaker 1: hardening if there is too much salt in the blood, 51 00:03:22,480 --> 00:03:26,960 Speaker 1: and treatments for this hardened pulse include acupuncture and the 52 00:03:27,040 --> 00:03:30,200 Speaker 1: removal of blood through things like blood letting and leeches. 53 00:03:30,960 --> 00:03:33,520 Speaker 1: There are also references to the pulse being used to 54 00:03:33,560 --> 00:03:37,600 Speaker 1: diagnose illnesses in several Egyptian medical texts dating back to 55 00:03:37,640 --> 00:03:41,520 Speaker 1: about thirty five hundred years ago. Some of these directly 56 00:03:41,600 --> 00:03:43,920 Speaker 1: connect the pulse in other parts of the body to 57 00:03:44,000 --> 00:03:47,400 Speaker 1: the beating of the heart and to blood flow. Moving 58 00:03:47,440 --> 00:03:51,440 Speaker 1: ahead to the eleventh century c E. Past podcast subject 59 00:03:51,520 --> 00:03:56,200 Speaker 1: even Sina, whose name is sometimes westernives does Avicenna wrote 60 00:03:56,280 --> 00:03:59,760 Speaker 1: quote the pulse is a movement in the heart and arteries, 61 00:04:00,080 --> 00:04:04,320 Speaker 1: which takes the form of alternate expansion and contraction, whereby 62 00:04:04,480 --> 00:04:08,920 Speaker 1: the breath becomes subjected to the influence of the air inspired. 63 00:04:09,600 --> 00:04:13,040 Speaker 1: The first person to document the circulation of blood throughout 64 00:04:13,040 --> 00:04:17,400 Speaker 1: the body was English physician William Harvey in s so 65 00:04:17,480 --> 00:04:20,640 Speaker 1: to be clear here, there was already plenty of commentary 66 00:04:20,720 --> 00:04:24,560 Speaker 1: on various aspects of the heart, the blood, blood vessels, 67 00:04:24,600 --> 00:04:28,360 Speaker 1: and the pulse. But before this point, the conventional wisdom 68 00:04:28,480 --> 00:04:31,080 Speaker 1: was at the heart pumped blood out to the tissues, 69 00:04:31,440 --> 00:04:35,440 Speaker 1: where it left the blood vessels and was absorbed. Harvey, 70 00:04:35,480 --> 00:04:38,640 Speaker 1: on the other hand, described circulation as a closed loop, 71 00:04:38,800 --> 00:04:41,440 Speaker 1: with the blood moving through the lungs and out to 72 00:04:41,480 --> 00:04:44,240 Speaker 1: the body and back. Yeah. I read a paper that 73 00:04:44,320 --> 00:04:50,720 Speaker 1: described him as single handedly discovering circulation, and I was like, nah, 74 00:04:50,400 --> 00:04:53,520 Speaker 1: that's a little reductive, building on the work of the 75 00:04:53,560 --> 00:04:57,600 Speaker 1: people who came before him. The first measurement of the 76 00:04:57,680 --> 00:05:02,400 Speaker 1: pressure inside this system, specifically in an artery, happened more 77 00:05:02,480 --> 00:05:06,520 Speaker 1: than a century later, thanks to English clergyman Stephen Hales, 78 00:05:06,520 --> 00:05:09,839 Speaker 1: who did experiments in all kinds of subjects related to 79 00:05:09,920 --> 00:05:14,080 Speaker 1: plant and animal physiology. Hales was building off of an 80 00:05:14,120 --> 00:05:19,279 Speaker 1: invention by past podcast subject Evangelista Torricelli. This was the 81 00:05:19,400 --> 00:05:23,960 Speaker 1: manometer that was a device used to measure pressure. Torricelli 82 00:05:24,120 --> 00:05:27,720 Speaker 1: used a mercury filled glass tube, but Hale's approach here 83 00:05:27,760 --> 00:05:31,160 Speaker 1: was a little bit different. He inserted a brass tube 84 00:05:31,279 --> 00:05:34,320 Speaker 1: into the artery of a horse, and he connected that 85 00:05:34,400 --> 00:05:38,240 Speaker 1: tube to a long glass pipe. He wrote about this 86 00:05:38,360 --> 00:05:43,760 Speaker 1: in his seventeen thirty three treatise Statical Essays containing Hemosthetics. 87 00:05:44,360 --> 00:05:47,279 Speaker 1: The horse needed to be euthanized because of a fistula 88 00:05:47,360 --> 00:05:49,880 Speaker 1: on its withers, which at the time was not really 89 00:05:49,920 --> 00:05:53,479 Speaker 1: a treatable condition, and Hales had it restrained on the 90 00:05:53,520 --> 00:05:57,360 Speaker 1: ground for an experiment. He wrote quote, having laid open 91 00:05:57,400 --> 00:06:00,680 Speaker 1: the left curl artery about three inches from her belly, 92 00:06:00,720 --> 00:06:03,919 Speaker 1: I inserted into it a brass pipe whose bore was 93 00:06:04,000 --> 00:06:07,200 Speaker 1: one sixth of an inch in diameter. I fixed a 94 00:06:07,240 --> 00:06:10,560 Speaker 1: glass tube of nearly the same diameter, from which was 95 00:06:10,680 --> 00:06:14,760 Speaker 1: nine ft in length, then untying the ligature of the artery. 96 00:06:14,960 --> 00:06:18,040 Speaker 1: The blood rose in the tube eight ft three inches 97 00:06:18,440 --> 00:06:22,040 Speaker 1: perpendicular above the level of the left ventricle of the heart, 98 00:06:22,600 --> 00:06:25,359 Speaker 1: but it did not attain to its full height at once. 99 00:06:25,960 --> 00:06:28,239 Speaker 1: When it was at its full height, it would rise 100 00:06:28,360 --> 00:06:32,440 Speaker 1: and fall at and after each pulse two three or 101 00:06:32,520 --> 00:06:35,680 Speaker 1: four inches. So just the note if you go to 102 00:06:35,720 --> 00:06:38,719 Speaker 1: look for more about this experiment number one, there is 103 00:06:38,760 --> 00:06:42,760 Speaker 1: a widely used illustration of this experiment that shows the 104 00:06:42,800 --> 00:06:46,520 Speaker 1: tube and the horse's neck that is incorrect based on 105 00:06:46,600 --> 00:06:50,080 Speaker 1: what we just read, But beyond that, the experiment continued 106 00:06:50,160 --> 00:06:52,600 Speaker 1: on from here. It is a little disturbing to read. 107 00:06:52,839 --> 00:06:56,560 Speaker 1: It resulted in the animal's death, which again the animal 108 00:06:56,640 --> 00:06:59,720 Speaker 1: needed to be euthanized, but this would not have been 109 00:06:59,720 --> 00:07:02,760 Speaker 1: the most humane way to do it. For a while 110 00:07:02,920 --> 00:07:07,120 Speaker 1: after this, most blood pressure measurements were invasive. They involved 111 00:07:07,120 --> 00:07:11,440 Speaker 1: putting something inside an artery to take a reading. For example, 112 00:07:11,560 --> 00:07:15,960 Speaker 1: Jean leonar Marie Poise did experiments on dogs and wrote 113 00:07:15,960 --> 00:07:23,160 Speaker 1: about them in his dissertation recher Left Artique. He placed 114 00:07:23,160 --> 00:07:26,400 Speaker 1: a mercury monometer into the dog's artery with a barrier 115 00:07:26,440 --> 00:07:30,520 Speaker 1: of potassium carbonate or potash to keep the blood from clotting. 116 00:07:31,320 --> 00:07:34,840 Speaker 1: Possoy made a number of observations from this work, including 117 00:07:34,880 --> 00:07:37,880 Speaker 1: that dog's blood pressure rose and fell as they breathed 118 00:07:37,920 --> 00:07:41,200 Speaker 1: in and out. Through the mid to late nineteenth century, 119 00:07:41,440 --> 00:07:44,880 Speaker 1: many doctors and physiologists tried to work out a non 120 00:07:44,920 --> 00:07:48,440 Speaker 1: invasive way to measure people's blood pressure. Most of them 121 00:07:48,440 --> 00:07:51,680 Speaker 1: involved measuring how much pressure it took to compress a 122 00:07:51,720 --> 00:07:55,000 Speaker 1: person's artery until the blood could no longer flow through it, 123 00:07:55,080 --> 00:07:58,200 Speaker 1: So sort of like if you pinch a straw until 124 00:07:58,240 --> 00:08:01,280 Speaker 1: you can't suck any liquid through it in anymore. This 125 00:08:01,480 --> 00:08:04,680 Speaker 1: was a measure of systolic blood pressure, in other words, 126 00:08:04,760 --> 00:08:07,880 Speaker 1: how much pressure is exerted on the artery every time 127 00:08:07,920 --> 00:08:12,640 Speaker 1: the heart beats. One such doctor was ju Risson, who 128 00:08:12,640 --> 00:08:15,440 Speaker 1: wrote a treatise on a device called this phigmometer in 129 00:08:15,520 --> 00:08:20,320 Speaker 1: eight five. There were several variations on this device, usually 130 00:08:20,440 --> 00:08:24,440 Speaker 1: combining a mercury column, a pressure gauge or dial, and 131 00:08:24,480 --> 00:08:27,200 Speaker 1: a piece that would be placed over the radial artery 132 00:08:27,320 --> 00:08:30,720 Speaker 1: in a person's inner wrist. Sometimes that piece was a 133 00:08:30,760 --> 00:08:33,160 Speaker 1: flat metal disc or a metal ball, but it was 134 00:08:33,240 --> 00:08:36,760 Speaker 1: often flexible like a membrane or rubber ball, or a 135 00:08:36,840 --> 00:08:40,840 Speaker 1: stretched piece of leather like a drumhead. To use this phigmometer, 136 00:08:41,120 --> 00:08:44,240 Speaker 1: a physician would place the device onto a person's wrist 137 00:08:44,760 --> 00:08:47,319 Speaker 1: and feel their pulse at a point that was below 138 00:08:47,400 --> 00:08:50,720 Speaker 1: the device. Then they would press the device. Usually that 139 00:08:50,800 --> 00:08:53,720 Speaker 1: flexible part into the wrist until they could no longer 140 00:08:53,800 --> 00:08:56,360 Speaker 1: feel the pulse below it. Then they would look at 141 00:08:56,360 --> 00:08:58,360 Speaker 1: the gauge or the dial to get a measurement of 142 00:08:58,360 --> 00:09:01,199 Speaker 1: how much pressure they were exerting. This reminds me a 143 00:09:01,240 --> 00:09:03,320 Speaker 1: little bit of those tire pressure gauges that have a 144 00:09:03,320 --> 00:09:05,960 Speaker 1: little thing that shoots out of the end. So this 145 00:09:06,120 --> 00:09:09,600 Speaker 1: device had some pros and cons. It was not invasive, 146 00:09:09,760 --> 00:09:13,000 Speaker 1: and compact and portable, but it was also pretty tricky 147 00:09:13,080 --> 00:09:16,240 Speaker 1: to read, and eventually it became apparent that it wasn't 148 00:09:16,320 --> 00:09:20,240 Speaker 1: very accurate. It was relying on like a person manually 149 00:09:20,240 --> 00:09:22,520 Speaker 1: pushing on a thing while feeling something with their fingers. 150 00:09:22,520 --> 00:09:25,280 Speaker 1: It was just a little prone to error, much like 151 00:09:25,360 --> 00:09:30,719 Speaker 1: those little tire gauges. In eighteen forty seven, German physiologist 152 00:09:30,800 --> 00:09:35,080 Speaker 1: Carl Ludwig developed a chemography on which combined amnometer with 153 00:09:35,120 --> 00:09:38,720 Speaker 1: a stylus and a revolving drum to record variations in 154 00:09:38,760 --> 00:09:44,479 Speaker 1: blood pressure on a graph. Unlike Harrison's figmometer, this was invasive. 155 00:09:45,000 --> 00:09:47,560 Speaker 1: The mnometer had to be placed in an artery, and 156 00:09:47,679 --> 00:09:51,400 Speaker 1: Ludwig used this for experiments on dogs, but it did 157 00:09:51,480 --> 00:09:55,200 Speaker 1: make it possible to record ongoing fluctuations in blood pressure. 158 00:09:55,520 --> 00:09:59,080 Speaker 1: As they were happening in the eighteen fifties and sixties, 159 00:09:59,200 --> 00:10:02,800 Speaker 1: lots of physicians and physiologists were still trying to find 160 00:10:03,280 --> 00:10:06,920 Speaker 1: non invasive ways to measure blood pressure, now, ones that 161 00:10:06,960 --> 00:10:10,640 Speaker 1: would be more consistent and more precise than this pigmometer was. 162 00:10:11,360 --> 00:10:14,760 Speaker 1: One result was this figma graph that was developed and 163 00:10:14,800 --> 00:10:19,440 Speaker 1: improved by multiple people, including German physiologist Carl von der 164 00:10:19,480 --> 00:10:24,240 Speaker 1: Roort and French physiologist Etien joul Maray. This was a 165 00:10:24,240 --> 00:10:27,920 Speaker 1: device placed over the inner wrist. It used springs and 166 00:10:28,040 --> 00:10:31,480 Speaker 1: levers to magnify the movement of the radial pulse and 167 00:10:31,520 --> 00:10:33,920 Speaker 1: then all this was connected to a stylist that could 168 00:10:33,960 --> 00:10:37,680 Speaker 1: record that movement as a graph. If small weights were 169 00:10:37,679 --> 00:10:42,040 Speaker 1: placed onto the device slowly weighing it down, the pulse 170 00:10:42,040 --> 00:10:45,319 Speaker 1: would eventually stop, so this could also provide a measurement 171 00:10:45,360 --> 00:10:49,280 Speaker 1: for blood pressure. Starting in the eighteen seventies and continuing 172 00:10:49,360 --> 00:10:53,240 Speaker 1: until his death in eighteen eighty four, Frederick Akbar Mohammed 173 00:10:53,440 --> 00:10:57,400 Speaker 1: researched blood pressure at Guy's Hospital in London. Mohammed was 174 00:10:57,440 --> 00:11:00,480 Speaker 1: born in England and was of Irish and in the descent, 175 00:11:00,960 --> 00:11:04,480 Speaker 1: and he developed and improved quantitative spygmagraph While he was 176 00:11:04,559 --> 00:11:07,679 Speaker 1: still in medical school, and he used this to make 177 00:11:07,720 --> 00:11:11,640 Speaker 1: a lot of significant discoveries about blood pressure and circulation 178 00:11:12,080 --> 00:11:15,000 Speaker 1: over the course of about a decade. Some of the 179 00:11:15,040 --> 00:11:17,200 Speaker 1: patients he worked with were under the care of his 180 00:11:17,280 --> 00:11:21,960 Speaker 1: colleague Richard Bright. Mohammed was able to determine that patients 181 00:11:21,960 --> 00:11:26,080 Speaker 1: who had kidney disease then known as Bright's disease tended 182 00:11:26,120 --> 00:11:28,920 Speaker 1: to have higher blood pressure. He also found that there 183 00:11:28,960 --> 00:11:32,120 Speaker 1: were people who had higher blood pressure but no evidence 184 00:11:32,160 --> 00:11:35,920 Speaker 1: of kidney dysfunction. He crossed reference to his blood pressure 185 00:11:35,920 --> 00:11:40,439 Speaker 1: measurements with autopsy reports to document how high blood pressure 186 00:11:40,480 --> 00:11:44,079 Speaker 1: could be related to things like kidney damage, arterial fibrosis, 187 00:11:44,160 --> 00:11:47,920 Speaker 1: and youeurysms and enlarged hearts. Sometimes he was credited with 188 00:11:47,960 --> 00:11:52,400 Speaker 1: coining the term essential hypertension, although sometimes that credit goes 189 00:11:52,440 --> 00:11:55,800 Speaker 1: to physiologist Otto Frank, who was working a few decades later. 190 00:11:56,559 --> 00:11:59,240 Speaker 1: Mohammed was one of the first people to suggest that 191 00:11:59,320 --> 00:12:02,680 Speaker 1: lowering a per since blood pressure could prolong their life, 192 00:12:02,800 --> 00:12:05,040 Speaker 1: and that is something we will get too more after 193 00:12:05,120 --> 00:12:18,440 Speaker 1: a sponsor break Frederick Akbar. Mohammed's contributions to the study 194 00:12:18,440 --> 00:12:21,640 Speaker 1: of blood pressure and hypertension are notable on their own. 195 00:12:21,880 --> 00:12:24,000 Speaker 1: I mean he made a lot of connections that still 196 00:12:24,000 --> 00:12:27,840 Speaker 1: hold up today. They're even more impressive considering that he 197 00:12:27,960 --> 00:12:32,040 Speaker 1: was using equipment that could be fiddly, encumbersome. Set up 198 00:12:32,080 --> 00:12:35,680 Speaker 1: tended to be complicated, it wasn't particularly comfortable for the patient. 199 00:12:35,960 --> 00:12:40,079 Speaker 1: Using a spig McGraph often involved strapping the patient's forearm 200 00:12:40,160 --> 00:12:42,960 Speaker 1: to a chair in a particular position, and then if 201 00:12:42,960 --> 00:12:46,280 Speaker 1: anything was misaligned and those levers and springs, the readings 202 00:12:46,280 --> 00:12:49,760 Speaker 1: would be inaccurate. But in the eighteen eighties people started 203 00:12:49,760 --> 00:12:52,320 Speaker 1: developing tools to measure blood pressure that are a lot 204 00:12:52,400 --> 00:12:55,720 Speaker 1: more in line with what is used today. The first 205 00:12:55,880 --> 00:12:58,880 Speaker 1: was Siegfried Karl Ridder von Bosch, who was a Jewish 206 00:12:58,880 --> 00:13:02,720 Speaker 1: physician from Austria. In eighteen eighty one, he developed an 207 00:13:02,720 --> 00:13:06,720 Speaker 1: inflatable bag that could be pressed against an artery. It 208 00:13:06,760 --> 00:13:09,480 Speaker 1: was connected to a pressure gauge, so a physician could 209 00:13:09,480 --> 00:13:12,520 Speaker 1: record how much pressure it took to collapse an artery 210 00:13:12,600 --> 00:13:17,520 Speaker 1: until blood could no longer pass through. Italian physician Shipione 211 00:13:17,640 --> 00:13:22,439 Speaker 1: Riva Rocchi improved on this in eight he created an 212 00:13:22,440 --> 00:13:26,280 Speaker 1: inflatable cuff that could be placed around the patient's arm 213 00:13:26,320 --> 00:13:29,280 Speaker 1: and then the physician would once again feel the person's 214 00:13:29,320 --> 00:13:32,319 Speaker 1: pulse below the cuff. As the cuff was being inflated, 215 00:13:32,920 --> 00:13:35,480 Speaker 1: when the pulse stopped, they would measure that number on 216 00:13:35,520 --> 00:13:39,040 Speaker 1: a pressure gauge. This was essentially this Figmomme monitor that 217 00:13:39,160 --> 00:13:43,240 Speaker 1: is still used to measure blood pressure today. A key difference, though, 218 00:13:43,440 --> 00:13:46,679 Speaker 1: was that Riva Rocchi's cuff was pretty narrow, so as 219 00:13:46,720 --> 00:13:49,080 Speaker 1: it inflated, it would make a pretty sharp crease in 220 00:13:49,120 --> 00:13:52,400 Speaker 1: people's flesh, and that could reduce the accuracy of the readings. 221 00:13:53,040 --> 00:13:57,400 Speaker 1: In nineteen o one, German physician hinrichs On Recklinghausen improved 222 00:13:57,480 --> 00:14:01,199 Speaker 1: on Riva Rocchi's design by making the cuff eier. Soon 223 00:14:01,440 --> 00:14:04,319 Speaker 1: this device was being introduced into other parts of the world. 224 00:14:04,800 --> 00:14:08,200 Speaker 1: Theodore Janeway and Harvey Cushing helped popularize it in the 225 00:14:08,280 --> 00:14:12,959 Speaker 1: United States. Until this point, most non invasive blood pressure 226 00:14:12,960 --> 00:14:17,199 Speaker 1: measurements that involved feeling a person's pulse or less frequently 227 00:14:17,720 --> 00:14:20,720 Speaker 1: using some kind of device to create a graph. And 228 00:14:20,920 --> 00:14:26,400 Speaker 1: n OH five Nikolai Kortakoff used ascultation, or listening, paying 229 00:14:26,440 --> 00:14:29,640 Speaker 1: attention to the sounds of the turbulence in a person's 230 00:14:29,720 --> 00:14:33,840 Speaker 1: artery while inflating and deflating the cuff. He noticed a 231 00:14:33,920 --> 00:14:38,040 Speaker 1: distinct set of sounds depending on how much pressure the 232 00:14:38,080 --> 00:14:41,160 Speaker 1: device was exerting on a person's arm relative to their 233 00:14:41,200 --> 00:14:45,000 Speaker 1: blood pressure. He was using a stethoscope to do this. Obviously, 234 00:14:45,680 --> 00:14:49,080 Speaker 1: with the cuff on but not inflated, there was no sound. 235 00:14:49,760 --> 00:14:52,040 Speaker 1: If the cuff was inflated to a greater amount of 236 00:14:52,040 --> 00:14:55,440 Speaker 1: pressure than the person's systolic blood pressure, there would still 237 00:14:55,480 --> 00:14:58,680 Speaker 1: be no sound because no blood could get through. But 238 00:14:58,760 --> 00:15:01,640 Speaker 1: as he reduced the press sure again he started to 239 00:15:01,680 --> 00:15:04,800 Speaker 1: hear sounds as small amounts of blood were able to 240 00:15:04,840 --> 00:15:08,640 Speaker 1: get through the artery with each heartbeat. That onset of 241 00:15:08,680 --> 00:15:13,200 Speaker 1: sounds marked the person's systolic blood pressure. These sounds went 242 00:15:13,240 --> 00:15:16,360 Speaker 1: through a series of changes as he further reduced the 243 00:15:16,400 --> 00:15:20,120 Speaker 1: pressure in the cuff, and then the sounds would disappear entirely. 244 00:15:20,400 --> 00:15:22,920 Speaker 1: And the point where the sounds disappeared was the person's 245 00:15:22,960 --> 00:15:27,040 Speaker 1: diastolic blood pressure. It's the blood pressure in between heartbeats. 246 00:15:27,040 --> 00:15:30,400 Speaker 1: I don't think we've said before. These sounds are still 247 00:15:30,440 --> 00:15:33,920 Speaker 1: known as corticough sounds today. They are still used when 248 00:15:33,960 --> 00:15:37,280 Speaker 1: somebody is measuring blood pressure using us big momentometer and 249 00:15:37,320 --> 00:15:41,200 Speaker 1: a stethoscope. There are some variations that exactly when in 250 00:15:41,240 --> 00:15:43,920 Speaker 1: the cycle people think is the best time to say 251 00:15:43,960 --> 00:15:47,320 Speaker 1: that's the diastolic blood pressure. Though, as has been the 252 00:15:47,320 --> 00:15:51,120 Speaker 1: case with so so many other medical innovations on the show, 253 00:15:51,920 --> 00:15:56,040 Speaker 1: even though this provided a practical, reliable, noninvasive way to 254 00:15:56,080 --> 00:16:00,000 Speaker 1: measure most systolic and diastolic blood pressure, the medical commune 255 00:16:00,040 --> 00:16:03,520 Speaker 1: it he did not adopt it right away. Some doctors 256 00:16:03,560 --> 00:16:06,080 Speaker 1: just didn't like the idea of using a device like 257 00:16:06,160 --> 00:16:09,360 Speaker 1: this in medical practice. In the words of an article 258 00:16:09,360 --> 00:16:12,080 Speaker 1: in the British Medical Journal, by using machines as part 259 00:16:12,080 --> 00:16:16,040 Speaker 1: of medical diagnosis, quote, we popularize our sense and weaken 260 00:16:16,200 --> 00:16:20,440 Speaker 1: clinical acuity. Others just thought that a doctor's fingers were 261 00:16:20,480 --> 00:16:24,240 Speaker 1: a better, more sensitive tool than a stethoscope. There were 262 00:16:24,280 --> 00:16:27,520 Speaker 1: also people who had been using things like spigma graphs 263 00:16:27,600 --> 00:16:30,640 Speaker 1: or other devices, and they felt like the spigmommometer was 264 00:16:30,720 --> 00:16:34,760 Speaker 1: making things too easy. Like I said earlier, spigmo graphs 265 00:16:34,760 --> 00:16:37,720 Speaker 1: could require a lot of technical skill and precision to 266 00:16:37,720 --> 00:16:39,840 Speaker 1: set them up and use them correctly, and so there 267 00:16:39,920 --> 00:16:43,600 Speaker 1: was this sense that by being simpler and easier to use, 268 00:16:43,840 --> 00:16:47,320 Speaker 1: the sphigmo mimometer would just make the practice of medicine 269 00:16:47,400 --> 00:16:53,240 Speaker 1: less prestigious. The sphigmommometer made it much easier to measure 270 00:16:53,280 --> 00:16:56,360 Speaker 1: more people's blood pressure, though, so over the first three 271 00:16:56,400 --> 00:17:00,400 Speaker 1: decades of the twentieth century, researchers started seeing lots of 272 00:17:00,440 --> 00:17:05,040 Speaker 1: connections between high blood pressure and heart diseases, strokes, and death. 273 00:17:05,520 --> 00:17:08,640 Speaker 1: This was all happening in spite of the controversy over 274 00:17:08,640 --> 00:17:12,919 Speaker 1: this figmomnometer that was playing out in the medical community, 275 00:17:12,960 --> 00:17:15,960 Speaker 1: because most of this research was happening actually in another 276 00:17:16,040 --> 00:17:20,879 Speaker 1: industry entirely, and that was the life insurance industry. Life 277 00:17:20,880 --> 00:17:23,760 Speaker 1: insurance companies wanted to make sure that as often as 278 00:17:23,800 --> 00:17:27,199 Speaker 1: possible the people they were covering had a long life 279 00:17:27,359 --> 00:17:30,440 Speaker 1: and paid lots and lots of premiums before their policies 280 00:17:30,480 --> 00:17:32,680 Speaker 1: had to be paid out. So by the end of 281 00:17:32,720 --> 00:17:36,520 Speaker 1: the nineteenth century, assessing a customer's health had become an 282 00:17:36,640 --> 00:17:40,639 Speaker 1: established industry practice. If somebody wanted insurance, they would be 283 00:17:40,680 --> 00:17:44,680 Speaker 1: examined by an insurance company physician, and then underwriters would 284 00:17:44,760 --> 00:17:48,080 Speaker 1: use the physician's report to decide whether ensuring this person 285 00:17:48,600 --> 00:17:52,360 Speaker 1: was an acceptable risk for the company. Over time, all 286 00:17:52,440 --> 00:17:55,800 Speaker 1: this data would inform things like actuarial tables that the 287 00:17:55,800 --> 00:17:58,960 Speaker 1: company could use to estimate how long a person could 288 00:17:59,000 --> 00:18:02,960 Speaker 1: be expected to live. Here in the US, it's pretty 289 00:18:03,000 --> 00:18:05,440 Speaker 1: much still how it happens today, although there are plans 290 00:18:05,480 --> 00:18:08,399 Speaker 1: that don't require physical exams, and a lot of plans 291 00:18:08,440 --> 00:18:11,800 Speaker 1: that are offered through employers as an employee benefit don't 292 00:18:11,800 --> 00:18:16,720 Speaker 1: require an exam below a certain monetary threshold. In nineteen 293 00:18:16,720 --> 00:18:21,040 Speaker 1: o six, Northwestern Mutual Life Insurance Company started measuring the 294 00:18:21,040 --> 00:18:23,760 Speaker 1: blood pressure of all of its clients as part of 295 00:18:23,800 --> 00:18:30,160 Speaker 1: their insurance applications. Other insurance companies followed suit. In nineteen eleven, 296 00:18:30,240 --> 00:18:34,080 Speaker 1: Dr J. W. Fisher, medical director of the Northwestern Mutual 297 00:18:34,119 --> 00:18:37,760 Speaker 1: Life Insurance Company, gave an address before the Medical Directors 298 00:18:37,800 --> 00:18:41,840 Speaker 1: Association which set, in part quote, no practitioner of medicine 299 00:18:41,840 --> 00:18:45,600 Speaker 1: should be without a spigmomanometer. He has in this instrument 300 00:18:45,720 --> 00:18:51,040 Speaker 1: a most valuable aid in diagnosis. This figmomanometer is indispensable 301 00:18:51,119 --> 00:18:54,480 Speaker 1: in life insurance examinations, and the time is not far 302 00:18:54,560 --> 00:18:58,680 Speaker 1: distant when all progressive life insurance companies will require its 303 00:18:58,800 --> 00:19:02,240 Speaker 1: use in all examine nations of applicants for life insurance. 304 00:19:03,000 --> 00:19:06,720 Speaker 1: By the nineteen thirties, the life insurance industry had gathered 305 00:19:06,800 --> 00:19:11,200 Speaker 1: data from more than ten million people. They're putting together 306 00:19:11,280 --> 00:19:14,800 Speaker 1: reports on that data, and it showed clear connections between 307 00:19:14,880 --> 00:19:19,520 Speaker 1: high blood pressure and other diseases, including cardiovascular diseases and 308 00:19:19,640 --> 00:19:23,800 Speaker 1: kidney disease. There was also a clear correlation between high 309 00:19:23,800 --> 00:19:27,920 Speaker 1: blood pressure and a shorter life expectancy. This data still 310 00:19:28,000 --> 00:19:31,600 Speaker 1: had some big limitations though. Number One, These companies were 311 00:19:31,640 --> 00:19:36,040 Speaker 1: primarily ensuring white people, specifically white men, as we talked 312 00:19:36,080 --> 00:19:39,000 Speaker 1: about in our episode on Maggie Lena Walker. There were 313 00:19:39,080 --> 00:19:43,800 Speaker 1: mutual aid organizations, fraternal orders, and other organizations that offered 314 00:19:43,800 --> 00:19:46,680 Speaker 1: insurance to people of color, but they were not included 315 00:19:46,760 --> 00:19:50,160 Speaker 1: in this data set. Number two. As the company saw 316 00:19:50,240 --> 00:19:55,240 Speaker 1: correlations between hypertension and early death, they started declining coverage 317 00:19:55,280 --> 00:19:58,840 Speaker 1: for people whose blood pressure was too high. Number three. 318 00:19:59,320 --> 00:20:02,440 Speaker 1: There was a lot of ongoing follow up. People were 319 00:20:02,440 --> 00:20:05,840 Speaker 1: either approved for insurance or they weren't, and unless people 320 00:20:05,880 --> 00:20:09,560 Speaker 1: wanted to change their coverage and that change required another examination, 321 00:20:10,040 --> 00:20:12,600 Speaker 1: the company did not check in on them again until 322 00:20:12,640 --> 00:20:16,719 Speaker 1: they died. Although the life insurance industry had a wealth 323 00:20:16,880 --> 00:20:20,439 Speaker 1: of data suggesting a connection between high blood pressure and 324 00:20:20,560 --> 00:20:24,600 Speaker 1: other diseases and reduced life expectancy, there was still a 325 00:20:24,600 --> 00:20:26,840 Speaker 1: lot of debate about all this in the medical community. 326 00:20:27,480 --> 00:20:31,320 Speaker 1: Measuring patients blood pressure eventually did become a standard practice 327 00:20:31,480 --> 00:20:34,480 Speaker 1: and by the nineteen teams, at least some doctors and 328 00:20:34,520 --> 00:20:38,080 Speaker 1: researchers thought high blood pressure should be classified as a disease, 329 00:20:38,720 --> 00:20:41,360 Speaker 1: but there was a lot of disagreement about how to define. 330 00:20:41,560 --> 00:20:46,199 Speaker 1: High blood pressure is generally measured in millimeters of mercury, 331 00:20:46,400 --> 00:20:49,399 Speaker 1: and the idea that one twenty over eighty millimeters of 332 00:20:49,440 --> 00:20:53,439 Speaker 1: mercury was normal that showed up pretty early in this 333 00:20:53,480 --> 00:20:57,480 Speaker 1: whole process. But some experts in the early twentieth century 334 00:20:57,480 --> 00:21:01,280 Speaker 1: thought that normal got higher as people age, and various 335 00:21:01,280 --> 00:21:05,040 Speaker 1: researchers cited numbers as high as one eight over one 336 00:21:05,160 --> 00:21:09,439 Speaker 1: ten as normal. There also was not a consensus about 337 00:21:09,440 --> 00:21:12,760 Speaker 1: what caused high blood pressure, or whether high blood pressure 338 00:21:12,800 --> 00:21:16,520 Speaker 1: was really the body's compensation for something else, so a 339 00:21:16,520 --> 00:21:19,400 Speaker 1: lot of doctors thought lowering a person's blood pressure might 340 00:21:19,440 --> 00:21:22,760 Speaker 1: do them more harm than good, because what if their 341 00:21:22,760 --> 00:21:25,719 Speaker 1: blood pressure needed to be that high to move their 342 00:21:25,800 --> 00:21:30,080 Speaker 1: circulation through clogged or hardened arteries, for example. To add 343 00:21:30,119 --> 00:21:33,280 Speaker 1: to all of that, there weren't really effective treatments for 344 00:21:33,359 --> 00:21:37,320 Speaker 1: hypertension at this point, even if a doctor wanted to try. 345 00:21:37,520 --> 00:21:41,480 Speaker 1: The idea that salt intake, or more specifically sodium might 346 00:21:41,520 --> 00:21:44,160 Speaker 1: cause high blood pressure that had been around since nineteen 347 00:21:44,200 --> 00:21:48,480 Speaker 1: o four, when l Umbard and E. Bojard published Cause 348 00:21:48,640 --> 00:21:53,680 Speaker 1: de lie potension on arterial so based on that, doctors 349 00:21:53,720 --> 00:21:57,000 Speaker 1: often advised patients whose blood pressure was high to reduce 350 00:21:57,080 --> 00:21:59,880 Speaker 1: the salt in their diets. But there had been pay 351 00:22:00,000 --> 00:22:03,280 Speaker 1: Shans and that first study by Ambard and Bojard whose 352 00:22:03,280 --> 00:22:07,480 Speaker 1: blood pressure did not increase with their salt consumption. These 353 00:22:07,560 --> 00:22:10,280 Speaker 1: low salt diviots could also be really hard to stick to. 354 00:22:11,720 --> 00:22:14,680 Speaker 1: Plus there was i mean evidence going back from this 355 00:22:14,800 --> 00:22:18,160 Speaker 1: very first study that they might not work for everybody. 356 00:22:18,320 --> 00:22:21,600 Speaker 1: Doctors also tried various drugs to lower blood pressure in 357 00:22:21,600 --> 00:22:24,200 Speaker 1: the early twentieth century and found them to be only 358 00:22:24,400 --> 00:22:28,119 Speaker 1: somewhat effective at best. On a lot of these drugs 359 00:22:28,119 --> 00:22:32,200 Speaker 1: had serious and sometimes dangerous side effects. So with all 360 00:22:32,240 --> 00:22:34,800 Speaker 1: of that in mind, a lot of doctors thought that 361 00:22:34,960 --> 00:22:38,680 Speaker 1: as long as a patient wasn't showing other symptoms, their 362 00:22:38,680 --> 00:22:44,320 Speaker 1: blood pressure should be left alone. In British cartiologist John H. 363 00:22:44,320 --> 00:22:47,360 Speaker 1: Hay wrote an article in the British Medical Journal that's said, 364 00:22:47,400 --> 00:22:50,560 Speaker 1: in part quote, there is some truth in the saying 365 00:22:50,600 --> 00:22:53,119 Speaker 1: that the greatest danger to a man with high blood 366 00:22:53,119 --> 00:22:56,840 Speaker 1: pressure lies in its discovery, Because then some fool is 367 00:22:56,880 --> 00:23:00,480 Speaker 1: certain to try and reduce it. Sometimes that first part 368 00:23:00,480 --> 00:23:02,680 Speaker 1: of the quote is left out, making it seem like 369 00:23:02,720 --> 00:23:05,600 Speaker 1: the saying he was quoting was actually his entire statement, 370 00:23:05,960 --> 00:23:07,840 Speaker 1: and that he thought it was foolish to try to 371 00:23:07,880 --> 00:23:10,680 Speaker 1: reduce blood pressure. But this was in the context of 372 00:23:10,720 --> 00:23:14,280 Speaker 1: an article that started quote, no one can now afford 373 00:23:14,320 --> 00:23:17,760 Speaker 1: to be indifferent to the problems associated with variations in 374 00:23:17,760 --> 00:23:21,560 Speaker 1: blood pressure. For a high pressure is an abnormality which 375 00:23:21,600 --> 00:23:28,080 Speaker 1: always demands investigation, supervision, and careful treatment. American cardiologist Paul 376 00:23:28,200 --> 00:23:31,399 Speaker 1: Dudley White echoed Hayes sentiments a few years later in 377 00:23:31,480 --> 00:23:35,280 Speaker 1: nine seven, quote, the treatment of hypertension itself is a 378 00:23:35,359 --> 00:23:38,879 Speaker 1: difficult and almost hopeless task in the present state of 379 00:23:38,920 --> 00:23:42,000 Speaker 1: our knowledge, and in fact for aught. We know the 380 00:23:42,080 --> 00:23:46,119 Speaker 1: hypertension maybe an important compensatory mechanism which should not be 381 00:23:46,200 --> 00:23:49,199 Speaker 1: tampered with, even if it were certain we could control it. 382 00:23:49,840 --> 00:23:53,440 Speaker 1: A few years after that, though, President Franklin Delano roosevelt 383 00:23:53,600 --> 00:23:57,000 Speaker 1: death brought renewed focus to all of this. We'll talk 384 00:23:57,000 --> 00:24:08,720 Speaker 1: more about that after a sponsor break. The death of 385 00:24:08,800 --> 00:24:12,639 Speaker 1: President Franklin Delano Roosevelt brought some more public awareness to 386 00:24:12,640 --> 00:24:17,399 Speaker 1: the risks of uncontrolled hypertension. Roosevelt was first diagnosed with 387 00:24:17,520 --> 00:24:21,440 Speaker 1: hypertension in ninety seven, when he was fifty four. At 388 00:24:21,440 --> 00:24:24,159 Speaker 1: that time, his blood pressure was measured at one sixty 389 00:24:24,240 --> 00:24:28,720 Speaker 1: two over. No treatment was prescribed for him until four 390 00:24:28,800 --> 00:24:32,240 Speaker 1: years later, when his BP was measured at one over 391 00:24:32,280 --> 00:24:35,679 Speaker 1: one oh five. As we said earlier, though at this 392 00:24:35,720 --> 00:24:39,320 Speaker 1: point treatments for hypertension were really limited, so the President 393 00:24:39,400 --> 00:24:42,719 Speaker 1: was put on a low fat, low sodium diet. He 394 00:24:42,800 --> 00:24:45,679 Speaker 1: was advised to rest and get massages, and he was 395 00:24:45,720 --> 00:24:49,160 Speaker 1: put on the barbiturates phena barbital, which today is most 396 00:24:49,240 --> 00:24:52,480 Speaker 1: often used to treat seizure disorders as well as anxiety 397 00:24:52,520 --> 00:24:56,720 Speaker 1: and sleeplessness. This course of treatment was not effective, and 398 00:24:56,760 --> 00:25:01,400 Speaker 1: in February of nine, Roosevelt's blood pressure was measured at 399 00:25:01,440 --> 00:25:05,840 Speaker 1: two sixty over one fifty. He was also starting to 400 00:25:05,880 --> 00:25:09,480 Speaker 1: show signs of heart and liver failure. He attended the 401 00:25:09,560 --> 00:25:12,359 Speaker 1: Yalta Conference, which was a meeting of Allied leaders to 402 00:25:12,400 --> 00:25:16,240 Speaker 1: discuss the post World War two reconstruction, and other people 403 00:25:16,320 --> 00:25:21,000 Speaker 1: present expressed concerns about his health, including doubts about whether 404 00:25:21,040 --> 00:25:25,800 Speaker 1: he was cognitively alert. During that meeting, Winston Churchill's physician 405 00:25:25,880 --> 00:25:28,719 Speaker 1: remarked that Roosevelt looked like a man who only had 406 00:25:28,760 --> 00:25:31,719 Speaker 1: a few months to live. His blood pressure was not 407 00:25:31,760 --> 00:25:34,639 Speaker 1: the only thing involved in his overall health, but that 408 00:25:34,720 --> 00:25:36,520 Speaker 1: is the focus of this episode, so that sort of 409 00:25:36,560 --> 00:25:42,920 Speaker 1: sticking to On April twelfth, Roosevelt reported a bad headache 410 00:25:42,920 --> 00:25:45,640 Speaker 1: while he was sitting for a portrait. His blood pressure 411 00:25:45,680 --> 00:25:49,440 Speaker 1: was recorded at that time at three hundred over one. 412 00:25:50,280 --> 00:25:52,800 Speaker 1: Not long after that, he lost consciousness and died at 413 00:25:52,840 --> 00:25:56,800 Speaker 1: the age of sixty three. No autopsy was performed, but 414 00:25:57,040 --> 00:26:00,000 Speaker 1: his cause of death was reported as a cerebral hemorrhage. 415 00:26:00,040 --> 00:26:03,480 Speaker 1: It's a logical conclusion to draw from the symptoms that 416 00:26:03,480 --> 00:26:07,679 Speaker 1: were shown at the time. His physician, Admiral Rossty McIntyre, 417 00:26:07,800 --> 00:26:11,159 Speaker 1: reportedly said that this quote came out of clear sky. 418 00:26:11,320 --> 00:26:14,159 Speaker 1: Even though the president's blood pressure had been escalating for 419 00:26:14,280 --> 00:26:19,280 Speaker 1: years and was three day there was still a lack 420 00:26:19,320 --> 00:26:22,680 Speaker 1: of medical consensus about what to do about high blood pressure. 421 00:26:22,720 --> 00:26:27,040 Speaker 1: Though Tyson's Practice of Medicine is a major medical textbook 422 00:26:27,359 --> 00:26:31,960 Speaker 1: and in its edition had this to say about hypertension. Quote, 423 00:26:32,400 --> 00:26:35,159 Speaker 1: may not the elevation of systemic blood pressure be a 424 00:26:35,240 --> 00:26:39,560 Speaker 1: natural response to guarantee a normal circulation, To the heart, brain, 425 00:26:39,680 --> 00:26:44,520 Speaker 1: and kidneys. Essential hypertension. Over zealous attempts to lower the 426 00:26:44,560 --> 00:26:48,639 Speaker 1: pressure may do no good and often do harm. Many 427 00:26:48,720 --> 00:26:52,720 Speaker 1: cases of essential hypertension not only do not need any treatment, 428 00:26:53,160 --> 00:26:56,600 Speaker 1: but are much better off without it, so it was 429 00:26:56,640 --> 00:26:59,639 Speaker 1: pretty clear at this point that more medical research was needed. 430 00:27:00,280 --> 00:27:03,600 Speaker 1: There was a rice based diet developed by Walter Kempner 431 00:27:03,800 --> 00:27:06,920 Speaker 1: that was sometimes effective at reducing a person's blood pressure, 432 00:27:06,920 --> 00:27:10,840 Speaker 1: but it was extremely restrictive and not usually sustainable over 433 00:27:10,880 --> 00:27:14,400 Speaker 1: the long term. Various drugs are being used to try 434 00:27:14,400 --> 00:27:16,880 Speaker 1: to treat hypertension, but at this point they all had 435 00:27:16,920 --> 00:27:21,800 Speaker 1: some pretty unpleasant or even dangerous side effects. Ralphina serpentina 436 00:27:21,960 --> 00:27:25,199 Speaker 1: or Indian snake root, was developed into an anti hypertension 437 00:27:25,280 --> 00:27:28,760 Speaker 1: drug Resurping in India, and while it could lower a 438 00:27:28,800 --> 00:27:31,720 Speaker 1: person's blood pressure, it didn't work for everyone, and it 439 00:27:31,800 --> 00:27:35,800 Speaker 1: was also associated with things like vomiting, nightmares, and chest pains. 440 00:27:36,400 --> 00:27:40,639 Speaker 1: Hadrolyzine was a vasodilator that could cause headaches and rapid heartbeat, 441 00:27:40,640 --> 00:27:44,280 Speaker 1: and at large doses could cause a syndrome that resembled lupus. 442 00:27:45,119 --> 00:27:48,560 Speaker 1: Hexamathynium was a ganglion blocking agent that had to be 443 00:27:48,600 --> 00:27:53,000 Speaker 1: administered as injections, sometimes multiple times a day. There were 444 00:27:53,040 --> 00:27:57,400 Speaker 1: also attempts to control people's blood pressure through surgeries. One 445 00:27:57,440 --> 00:28:02,600 Speaker 1: was sympathectomy, or severing sympathetic nerves near the spine. Another 446 00:28:02,680 --> 00:28:06,159 Speaker 1: involved the removal of the adrenal glands. While a person's 447 00:28:06,160 --> 00:28:09,360 Speaker 1: blood pressure might be lower after one of these procedures, 448 00:28:09,400 --> 00:28:12,960 Speaker 1: this definitely was not true for everyone, and these procedures 449 00:28:13,000 --> 00:28:16,639 Speaker 1: were also really risky and irreversible. There are a lot 450 00:28:16,640 --> 00:28:19,439 Speaker 1: of things that were just regarded as quackery also, and 451 00:28:19,600 --> 00:28:24,160 Speaker 1: we are not getting into any of that. In President 452 00:28:24,200 --> 00:28:28,119 Speaker 1: Harry Truman signed the National Heart Act into law. This 453 00:28:28,320 --> 00:28:31,439 Speaker 1: law noted that diseases of the heart and circulatory system 454 00:28:31,480 --> 00:28:35,000 Speaker 1: had become the leading cause of death in the United States. 455 00:28:35,640 --> 00:28:39,120 Speaker 1: This law established the National Heart Institute and the Public 456 00:28:39,160 --> 00:28:42,800 Speaker 1: Health Service, as well as the National Advisory Heart Council. 457 00:28:43,360 --> 00:28:46,640 Speaker 1: The Framingham Heart Study was launched soon afterwards with the 458 00:28:46,640 --> 00:28:50,440 Speaker 1: goal of determining the causes of heart disease. The Framingham 459 00:28:50,480 --> 00:28:52,760 Speaker 1: Heart Study is actually still ongoing today. They're on their 460 00:28:52,840 --> 00:28:57,960 Speaker 1: third generation of research participants. Through the Framingham Heart Study 461 00:28:58,000 --> 00:29:01,040 Speaker 1: and other large scale long term study ease it became 462 00:29:01,120 --> 00:29:05,200 Speaker 1: increasingly clear that hypertension could cause heart and kidney problems, 463 00:29:05,240 --> 00:29:09,480 Speaker 1: including issues like left ventricular hypertrophy, and that lowering a 464 00:29:09,520 --> 00:29:13,360 Speaker 1: person's blood pressure could help prevent and sometimes even reverse 465 00:29:13,480 --> 00:29:18,120 Speaker 1: these issues. But actually reducing people's blood pressure continued to 466 00:29:18,120 --> 00:29:22,160 Speaker 1: be really difficult, so many doctors continued to treat hypertension 467 00:29:22,360 --> 00:29:25,280 Speaker 1: only if it seemed to be causing some other issue. 468 00:29:25,800 --> 00:29:29,520 Speaker 1: When hypertension wasn't being caused by some other disease or disorder, 469 00:29:30,040 --> 00:29:34,640 Speaker 1: it was increasingly known as essential hypertension, and many doctors 470 00:29:34,640 --> 00:29:37,920 Speaker 1: saw it as just an inevitable part of aging. That 471 00:29:38,040 --> 00:29:41,160 Speaker 1: started to change in the fall of nineteen fifty seven 472 00:29:41,240 --> 00:29:45,360 Speaker 1: when a clinical trial started for a diuretic called chlorothiazide. 473 00:29:46,280 --> 00:29:49,719 Speaker 1: This wasn't intentionally intended to be used as a treatment 474 00:29:49,760 --> 00:29:53,400 Speaker 1: for hypertension. Was the diuretic that doctors were prescribing to 475 00:29:53,480 --> 00:29:57,240 Speaker 1: patients who had edema due to congestive heart failure. But 476 00:29:57,280 --> 00:29:59,920 Speaker 1: when doctors gave their patients this medicine, they noticed that 477 00:30:00,000 --> 00:30:05,120 Speaker 1: their blood pressure dropped dramatically in night. This became available 478 00:30:05,160 --> 00:30:08,600 Speaker 1: at pharmacies under the brand name di a Ill. This 479 00:30:08,680 --> 00:30:12,000 Speaker 1: was during the massive boom in pharmaceutical development that took 480 00:30:12,040 --> 00:30:16,280 Speaker 1: place during and after World War two. So many new 481 00:30:16,400 --> 00:30:19,640 Speaker 1: drugs and classes of drugs were developed during this period, 482 00:30:20,040 --> 00:30:22,240 Speaker 1: several of which have come up on the show before. 483 00:30:23,080 --> 00:30:27,160 Speaker 1: Antibiotics entered mass production during the war and flourished afterward. 484 00:30:27,800 --> 00:30:31,280 Speaker 1: The first oral contraceptive was approved in nineteen sixty after 485 00:30:31,360 --> 00:30:34,400 Speaker 1: having been used to treat various gynecological disorders for a 486 00:30:34,400 --> 00:30:39,040 Speaker 1: few years before that. Tranquilizers were also introduced during this era, 487 00:30:39,120 --> 00:30:41,880 Speaker 1: which we talked about in our two parter on the litamide. 488 00:30:42,480 --> 00:30:45,840 Speaker 1: So Diarill was introduced at a time when there was 489 00:30:45,960 --> 00:30:49,920 Speaker 1: just an increasing focus on the idea that chronic illnesses 490 00:30:50,000 --> 00:30:54,280 Speaker 1: and conditions could be treated or controlled using pharmaceuticals. It 491 00:30:54,320 --> 00:30:57,040 Speaker 1: played a really big part in that shift. At this 492 00:30:57,120 --> 00:31:01,160 Speaker 1: point in the United States, the pharmaceutical industry not advertise 493 00:31:01,320 --> 00:31:05,600 Speaker 1: drugs directly to consumers, but merk Sharp and Dome, which 494 00:31:05,640 --> 00:31:08,960 Speaker 1: was the company that developed Direll, did things like distributing 495 00:31:09,160 --> 00:31:13,000 Speaker 1: research reports to science writers, which led to favorable write 496 00:31:13,040 --> 00:31:17,600 Speaker 1: ups in publications like Readers. Digest Mark also advertised to 497 00:31:17,800 --> 00:31:21,480 Speaker 1: doctors in medical journals, and they created a character called 498 00:31:21,600 --> 00:31:24,440 Speaker 1: di a rill Man as part of this campaign. This 499 00:31:24,640 --> 00:31:28,600 Speaker 1: was a transparent illustration of a man with the heart 500 00:31:28,720 --> 00:31:33,120 Speaker 1: and lungs and urinary system visible in that illustration. Di 501 00:31:33,320 --> 00:31:36,040 Speaker 1: arell Man became one of the first examples of a 502 00:31:36,080 --> 00:31:39,640 Speaker 1: physical gift that drug sales reps would leave with doctors. 503 00:31:39,920 --> 00:31:43,200 Speaker 1: This is a little transparent desk figuring about six inches 504 00:31:43,240 --> 00:31:46,600 Speaker 1: tall that had these organs visible on the inside of it, 505 00:31:46,640 --> 00:31:49,480 Speaker 1: and it was mostly filled up with water. I want 506 00:31:49,480 --> 00:31:52,080 Speaker 1: one so bad now you might be able to find 507 00:31:52,080 --> 00:31:55,240 Speaker 1: one on eBay. Oh, I'm gonna go looking. Although di 508 00:31:55,360 --> 00:31:59,560 Speaker 1: arell could still cause side effects like lightheadedness and digestive problems, 509 00:32:00,040 --> 00:32:03,240 Speaker 1: it was overall more broadly effective than the earlier drugs 510 00:32:03,280 --> 00:32:06,200 Speaker 1: that were used to treat hypertension, and those side effects 511 00:32:06,200 --> 00:32:10,960 Speaker 1: were generally less serious and more widely tolerated. This made 512 00:32:10,960 --> 00:32:13,719 Speaker 1: it possible to get a lot more data about what 513 00:32:13,800 --> 00:32:16,880 Speaker 1: worked and what happened when a person's high blood pressure 514 00:32:16,960 --> 00:32:20,600 Speaker 1: was lowered. As direl was making its way to market, 515 00:32:20,720 --> 00:32:25,440 Speaker 1: Dr Irvine Page proposed the mosaic theory of hypertension. This 516 00:32:25,600 --> 00:32:28,280 Speaker 1: built on ideas he had started putting forth as early 517 00:32:28,320 --> 00:32:31,920 Speaker 1: as ninety seven, and he argued that there were multiple 518 00:32:31,960 --> 00:32:37,240 Speaker 1: interrelated factors at work in maintaining the bodies blood pressure equilibrium. 519 00:32:37,320 --> 00:32:43,920 Speaker 1: You thought that blood pressure involved genetic, environmental, anatomical, adaptive, neural, indocrine, humoral, 520 00:32:44,000 --> 00:32:47,760 Speaker 1: and hemodynamic factors. You can get a direl man for 521 00:32:47,920 --> 00:32:53,600 Speaker 1: just like twenty five bucks. Di arell marked a major 522 00:32:53,720 --> 00:32:57,200 Speaker 1: shift in the treatment of hypertension, and thanks to that shift, 523 00:32:57,640 --> 00:33:00,480 Speaker 1: it's tricky to do a historical playbi a of all 524 00:33:00,520 --> 00:33:05,200 Speaker 1: the new developments since then, even just as highlights, because simultaneously, 525 00:33:05,400 --> 00:33:08,200 Speaker 1: so much has happened in terms of drug development and 526 00:33:08,240 --> 00:33:13,520 Speaker 1: research into hypertension, and so much is still unknown. Like 527 00:33:13,640 --> 00:33:16,480 Speaker 1: diarrhal and other, diuretics were just the first class of 528 00:33:16,560 --> 00:33:20,640 Speaker 1: drugs developed to treat hypertension. Today there are at least ten, 529 00:33:20,800 --> 00:33:26,120 Speaker 1: including beta blockers, ACE inhibitors, and calcium channel blockers, most 530 00:33:26,160 --> 00:33:28,720 Speaker 1: of which were introduced over a period of only about 531 00:33:28,760 --> 00:33:33,240 Speaker 1: thirty years. The availability of these drugs and others made 532 00:33:33,280 --> 00:33:37,800 Speaker 1: it possible to conduct things like randomized, placebo controlled, double 533 00:33:37,880 --> 00:33:41,880 Speaker 1: blind trials of hypertension treatments. The first of these were 534 00:33:41,920 --> 00:33:46,720 Speaker 1: conducted through the US Veterans Administration. These studies have provided 535 00:33:46,800 --> 00:33:51,520 Speaker 1: clear evidence that reducing moderate and severe hypertension is beneficial 536 00:33:51,680 --> 00:33:55,840 Speaker 1: and can prolong people's lives. Based on this and other data, 537 00:33:56,000 --> 00:33:59,920 Speaker 1: widespread public education campaign started in the nineteen seventies for 538 00:34:00,040 --> 00:34:03,840 Speaker 1: both doctors and the general public. This includes the National 539 00:34:03,920 --> 00:34:07,280 Speaker 1: High blood Pressure Education Program, which launched in the US 540 00:34:07,360 --> 00:34:11,000 Speaker 1: in nineteen seventy two. There have also been so many 541 00:34:11,080 --> 00:34:14,759 Speaker 1: other studies since then, including other studies at the v A. 542 00:34:15,480 --> 00:34:18,800 Speaker 1: They've looked at so many questions around things like correlations 543 00:34:18,800 --> 00:34:25,080 Speaker 1: with other conditions, race, gender, the efficacy of different drugs, diet, exercise, age, 544 00:34:25,120 --> 00:34:30,160 Speaker 1: tobacco used, diabetes, on and on and on. Through this research, 545 00:34:30,360 --> 00:34:33,520 Speaker 1: guidelines for how to define high blood pressure and how 546 00:34:33,560 --> 00:34:38,400 Speaker 1: to treat it have become increasingly aggressive and specific. For example, 547 00:34:38,520 --> 00:34:43,640 Speaker 1: in the US, the Joint National Committee on Prevention, Detection, Evaluation, 548 00:34:43,680 --> 00:34:46,440 Speaker 1: and Treatment of High blood Pressure issued its first report 549 00:34:46,480 --> 00:34:50,399 Speaker 1: in nineteen seventy seven. This report suggested that a person 550 00:34:50,440 --> 00:34:53,840 Speaker 1: who's blood pressure was one sixty over ninety five should 551 00:34:53,880 --> 00:34:56,600 Speaker 1: have it checked again in a month, while people fifty 552 00:34:56,600 --> 00:34:58,880 Speaker 1: and under should be checked every two to three months. 553 00:34:58,880 --> 00:35:02,000 Speaker 1: If their blood pressure was between one forty ninety and 554 00:35:02,000 --> 00:35:08,080 Speaker 1: one six probably not how a doctor would approach it today. 555 00:35:08,120 --> 00:35:11,360 Speaker 1: It's definitely not how my doctor did. And this report, 556 00:35:11,440 --> 00:35:14,720 Speaker 1: treatment was recommended only if a person's dia stylic blood 557 00:35:14,760 --> 00:35:17,280 Speaker 1: pressure was greater than or equal to one oh five. 558 00:35:18,040 --> 00:35:22,800 Speaker 1: Those numbers have dropped repeatedly since the seventies. Most recently 559 00:35:22,840 --> 00:35:26,600 Speaker 1: in seventeen, the American Heart Association and the American College 560 00:35:26,600 --> 00:35:31,400 Speaker 1: of Cardiology announced new guidelines that defined normal blood pressure 561 00:35:31,480 --> 00:35:34,640 Speaker 1: has less than one twenty over eighty, and everything above 562 00:35:34,760 --> 00:35:38,279 Speaker 1: one thirty over eighty is classified as some variety of hypertension. 563 00:35:39,000 --> 00:35:42,720 Speaker 1: A systylic reading above one eighty and a dia stylic 564 00:35:42,760 --> 00:35:46,680 Speaker 1: reading above one twenty either of those that's classified as 565 00:35:46,680 --> 00:35:51,680 Speaker 1: a hypertensive crisis, and the American Heart Association advises people 566 00:35:51,760 --> 00:35:54,440 Speaker 1: to contact their doctor immediately if this happens to them. 567 00:35:54,440 --> 00:35:57,359 Speaker 1: This is so radically different from earlier eras when there 568 00:35:57,360 --> 00:36:00,560 Speaker 1: were studies that classified one eight over one ten as normal. 569 00:36:01,320 --> 00:36:06,760 Speaker 1: There is also various conventional wisdom around hypertension that still 570 00:36:06,840 --> 00:36:10,920 Speaker 1: isn't fully supported or understood. We noted earlier that a 571 00:36:10,960 --> 00:36:14,800 Speaker 1: possible connection to sodium was first proposed in nineteen o four. 572 00:36:15,440 --> 00:36:19,200 Speaker 1: Today you can read all kinds of extremely authoritative, yet 573 00:36:19,239 --> 00:36:24,000 Speaker 1: totally contradictory, peer reviewed papers that describe sodium as everything 574 00:36:24,080 --> 00:36:27,600 Speaker 1: from the single biggest contributor to hypertension in the entire 575 00:36:27,680 --> 00:36:32,440 Speaker 1: world to something that can contribute to hypertension in some people, 576 00:36:32,840 --> 00:36:37,000 Speaker 1: but only if they are sensitive to sodium yets. I 577 00:36:37,160 --> 00:36:40,960 Speaker 1: found this very frustrating as I was trying to get 578 00:36:41,000 --> 00:36:44,799 Speaker 1: to this part of the episode. Another bit of conventional 579 00:36:44,840 --> 00:36:48,719 Speaker 1: wisdom has involved associating high blood pressure with being overweight, 580 00:36:48,880 --> 00:36:52,719 Speaker 1: and with recommendations for people to lose weight included as 581 00:36:52,760 --> 00:36:55,600 Speaker 1: a way to try to control their blood pressure. But 582 00:36:55,719 --> 00:36:58,960 Speaker 1: that is seemingly not as straightforward as all that number 583 00:36:58,960 --> 00:37:02,200 Speaker 1: one and abody can have high blood pressure regardless of 584 00:37:02,239 --> 00:37:05,760 Speaker 1: how much they weigh and number two. For a long time, 585 00:37:05,800 --> 00:37:09,240 Speaker 1: there was really only one size of blood pressure cuff 586 00:37:09,280 --> 00:37:11,800 Speaker 1: that was being used, and it was really too small 587 00:37:11,840 --> 00:37:16,080 Speaker 1: for people with bigger arms. It gave artificially high readings 588 00:37:16,120 --> 00:37:19,520 Speaker 1: for people who weighed more. Blessed people tends to weigh 589 00:37:19,520 --> 00:37:21,799 Speaker 1: more as they get older, and some of the very 590 00:37:21,960 --> 00:37:26,400 Speaker 1: earliest actuarial reports about this noted that quote the increase 591 00:37:26,440 --> 00:37:30,800 Speaker 1: of blood pressure with increasing percentage of overweight is exaggerated 592 00:37:31,280 --> 00:37:35,000 Speaker 1: because of that interaction between people's age and their weight. Today, 593 00:37:35,080 --> 00:37:40,200 Speaker 1: researchers are looking at people's genetics, salt sensitivity, congenital factors 594 00:37:40,239 --> 00:37:44,160 Speaker 1: like birth weight and stress during fetal development and so 595 00:37:44,239 --> 00:37:47,920 Speaker 1: many other factors. But the reality at this point is 596 00:37:47,960 --> 00:37:51,239 Speaker 1: that for the overwhelming number of people who have hypertension, 597 00:37:51,760 --> 00:37:54,879 Speaker 1: we don't know exactly why. We really don't know. It's 598 00:37:54,960 --> 00:37:59,520 Speaker 1: also frustrating. Also, while the blood pressure cuff has been 599 00:37:59,560 --> 00:38:02,640 Speaker 1: a stay entered piece of equipment for doctors and nurses 600 00:38:02,680 --> 00:38:06,120 Speaker 1: and various other health and medical practitioners for more than 601 00:38:06,160 --> 00:38:09,080 Speaker 1: a century, there are improvements in the works for that 602 00:38:09,160 --> 00:38:13,040 Speaker 1: as well. So beyond just cuffs that inflate themselves and 603 00:38:13,040 --> 00:38:15,279 Speaker 1: then give a readout of blood pressure and pulse on 604 00:38:15,320 --> 00:38:18,200 Speaker 1: a screen like I've been using at home as my 605 00:38:18,280 --> 00:38:22,360 Speaker 1: doctor instructed, there are also efforts to make noninvasive blood 606 00:38:22,360 --> 00:38:25,279 Speaker 1: pressure measurement tools that don't actually require a cuff at all. 607 00:38:26,120 --> 00:38:28,759 Speaker 1: They would work a little more like a pulse oxometer 608 00:38:28,880 --> 00:38:33,480 Speaker 1: that goes on a person's fingertip. That technology also needs 609 00:38:33,520 --> 00:38:36,360 Speaker 1: some work. Uh. We know at this point that pulse 610 00:38:36,360 --> 00:38:39,840 Speaker 1: oxometers often don't give readings that are correct on people 611 00:38:39,840 --> 00:38:43,120 Speaker 1: with darker skin, So there's there's a whole confluence of 612 00:38:43,120 --> 00:38:45,720 Speaker 1: things to keep in mind. There there are some finger 613 00:38:45,760 --> 00:38:48,400 Speaker 1: monitors that have already hit the market at various points, 614 00:38:48,400 --> 00:38:52,600 Speaker 1: but they've generally been seen as less accurate than monitors 615 00:38:52,600 --> 00:38:55,640 Speaker 1: that use a cuff, and then rist monitors that are 616 00:38:55,680 --> 00:38:58,840 Speaker 1: also on the market today are similarly seen as less 617 00:38:58,880 --> 00:39:03,160 Speaker 1: accurate than ones go around the upper arm. Um. There 618 00:39:03,200 --> 00:39:07,520 Speaker 1: would be a lot of pluses to having an accurate 619 00:39:07,560 --> 00:39:10,160 Speaker 1: way to measure blood pressure that didn't require a cuff, 620 00:39:11,239 --> 00:39:13,800 Speaker 1: in part because try and put a cuff on yourself 621 00:39:13,880 --> 00:39:22,560 Speaker 1: is annoying. So that's um. That's the brief history of hypertension, 622 00:39:22,680 --> 00:39:26,359 Speaker 1: especially up through the introduction of di rill. Uh. This 623 00:39:26,440 --> 00:39:29,560 Speaker 1: is not a solicitation for advice about my blood pressure. 624 00:39:29,600 --> 00:39:34,640 Speaker 1: Please and thank you. Tracy has a doctor. I sure 625 00:39:35,200 --> 00:39:38,719 Speaker 1: my doctors on the ball with my blood pressure. Do 626 00:39:38,840 --> 00:39:42,239 Speaker 1: you also have listener mail I do? This is from Samantha. 627 00:39:42,320 --> 00:39:44,319 Speaker 1: This is one of many, many, many notes that we 628 00:39:44,360 --> 00:39:47,279 Speaker 1: got about this. It was something that had crossed my 629 00:39:47,360 --> 00:39:50,040 Speaker 1: radar first thing in the morning. Um, and I'm sure 630 00:39:50,280 --> 00:39:53,160 Speaker 1: I will say it again on a future installment of 631 00:39:53,600 --> 00:39:56,960 Speaker 1: on Earth, but this the next Unearthed, is all the 632 00:39:56,960 --> 00:39:59,600 Speaker 1: way in October, and I would rather say something about 633 00:39:59,600 --> 00:40:02,480 Speaker 1: it now. So Samantha wrote, hello there. I came across 634 00:40:02,520 --> 00:40:04,919 Speaker 1: this article today and remembered that you both had done 635 00:40:04,920 --> 00:40:08,520 Speaker 1: an episode to part if I remember correctly on Jim Thorpe. 636 00:40:08,840 --> 00:40:11,040 Speaker 1: You probably already saw it, but I thought i'd pass 637 00:40:11,080 --> 00:40:13,960 Speaker 1: it along just in case. I'm always behind on the podcast, 638 00:40:14,000 --> 00:40:16,680 Speaker 1: so my apologies if it's already been mentioned. Can't wait 639 00:40:16,719 --> 00:40:20,520 Speaker 1: to hear more. And Samantha sent an article about Jim 640 00:40:20,560 --> 00:40:26,640 Speaker 1: Thorpe's Olympic record being restored. Jim Thorpe is the subject 641 00:40:26,640 --> 00:40:28,960 Speaker 1: of the only three parter we have ever done on 642 00:40:28,960 --> 00:40:31,040 Speaker 1: the show so far, and one of the things that 643 00:40:31,080 --> 00:40:35,400 Speaker 1: we talked about was a whole controversy involving whether some 644 00:40:35,560 --> 00:40:40,200 Speaker 1: of his athletic participation disqualified him from being an amateur athlete. 645 00:40:41,040 --> 00:40:44,920 Speaker 1: And so just on I think what was gonna be 646 00:40:45,040 --> 00:40:51,000 Speaker 1: the one anniversary of one of his Olympic wins, um 647 00:40:51,080 --> 00:40:56,759 Speaker 1: his Olympic record was restored. So uh, I'm sure I 648 00:40:56,760 --> 00:40:59,120 Speaker 1: will have a more thorough discussion of that at the 649 00:40:59,200 --> 00:41:02,200 Speaker 1: next un Earth, which is not until October, so it 650 00:41:02,320 --> 00:41:05,160 Speaker 1: was too good of a thing to wait until them. 651 00:41:05,200 --> 00:41:06,719 Speaker 1: If you would like to send us a note about 652 00:41:06,760 --> 00:41:09,520 Speaker 1: this or any other podcast, where a history podcast that 653 00:41:09,600 --> 00:41:12,400 Speaker 1: I heart radio dot com and we're all over social 654 00:41:12,440 --> 00:41:14,960 Speaker 1: media at miss in History. You'll find us there for 655 00:41:15,000 --> 00:41:18,239 Speaker 1: your Facebook, Twitter, Pinterest, and Instagram, and you can subscribe 656 00:41:18,280 --> 00:41:21,040 Speaker 1: to our show on the I heart Radio app and 657 00:41:21,120 --> 00:41:27,879 Speaker 1: wherever else you like to get podcasts. Stuff you Missed 658 00:41:27,880 --> 00:41:30,320 Speaker 1: in History Class is a production of I heart Radio. 659 00:41:30,680 --> 00:41:33,239 Speaker 1: For more podcasts from I heart Radio, visit the i 660 00:41:33,320 --> 00:41:36,520 Speaker 1: heart Radio app, Apple Podcasts, or wherever you listen to 661 00:41:36,560 --> 00:41:37,400 Speaker 1: your favorite shows.