1 00:00:01,320 --> 00:00:04,240 Speaker 1: Welcome to Stuff You Missed in History Class, a production 2 00:00:04,400 --> 00:00:14,360 Speaker 1: of iHeartRadio. Hello, and welcome to the podcast. I'm trace 3 00:00:14,400 --> 00:00:16,480 Speaker 1: E V. Wilson, and I'm Holly Frye. 4 00:00:16,960 --> 00:00:19,680 Speaker 2: I went to the doctor the other day. I think 5 00:00:19,720 --> 00:00:22,800 Speaker 2: that's where I picked up the cold that I feel 6 00:00:22,840 --> 00:00:25,360 Speaker 2: like is still present in my voice a little bit. 7 00:00:27,080 --> 00:00:29,400 Speaker 1: Probably that's for sick people off and arm. 8 00:00:29,600 --> 00:00:32,240 Speaker 2: No. I know I had a mask on the whole time, 9 00:00:32,320 --> 00:00:37,519 Speaker 2: but you know, stuff happens while I was there. The 10 00:00:37,560 --> 00:00:41,440 Speaker 2: doctor wanted to get an EKG, also called an ECG 11 00:00:41,920 --> 00:00:47,879 Speaker 2: or electro cardiogram. People use those EKG and ECG abbreviations 12 00:00:47,880 --> 00:00:51,600 Speaker 2: pretty much interchangeably. EKG is just the same word, but 13 00:00:51,840 --> 00:00:55,360 Speaker 2: in German. While I was waiting for somebody to come 14 00:00:55,400 --> 00:00:58,320 Speaker 2: back with the machine to do this test, I thought, 15 00:00:58,400 --> 00:01:01,640 Speaker 2: what was this inventedrobably like the twenties or the thirties, 16 00:01:02,680 --> 00:01:04,679 Speaker 2: And while waiting I looked it up on my phone 17 00:01:04,720 --> 00:01:08,280 Speaker 2: and the answer was eighteen ninety five. Of course, that 18 00:01:08,319 --> 00:01:11,360 Speaker 2: eighteen ninety five device looked a lot different from today's 19 00:01:11,480 --> 00:01:15,039 Speaker 2: electro cardiographs, which is what the machine is called. And 20 00:01:15,080 --> 00:01:18,080 Speaker 2: there are some other years on either side of eighteen 21 00:01:18,160 --> 00:01:22,679 Speaker 2: ninety five, that you could also say was the first regardless, 22 00:01:22,680 --> 00:01:27,559 Speaker 2: so that was earlier than I was expecting. So sitting 23 00:01:27,560 --> 00:01:29,640 Speaker 2: there at the doctor's office, I dropped what I was 24 00:01:29,720 --> 00:01:33,040 Speaker 2: working on for this show to do an electro cardiogram 25 00:01:33,080 --> 00:01:36,480 Speaker 2: episode instead as a confession. I was also working on 26 00:01:36,520 --> 00:01:40,040 Speaker 2: something that had turned out to be really unwieldy, and 27 00:01:40,120 --> 00:01:42,080 Speaker 2: while I was in the waiting room, I had been 28 00:01:42,120 --> 00:01:44,679 Speaker 2: sort of thinking through how in the world I was 29 00:01:44,760 --> 00:01:47,360 Speaker 2: going to get this unwieldy thing done in time to 30 00:01:47,440 --> 00:01:50,320 Speaker 2: record it. The unwieldy thing is still coming, it's just 31 00:01:50,360 --> 00:01:53,960 Speaker 2: coming later. Also, my ECG was normal in case people 32 00:01:54,000 --> 00:01:58,600 Speaker 2: are wondering, Like most of our episodes on medical developments, 33 00:01:58,640 --> 00:02:03,080 Speaker 2: this does include some animal experimentation. Also, if you're a 34 00:02:03,120 --> 00:02:06,480 Speaker 2: cardiologist or otherwise if you work with a lot of ECGs, 35 00:02:06,560 --> 00:02:09,519 Speaker 2: I'll just go ahead and apologize. We're not going to 36 00:02:09,560 --> 00:02:13,040 Speaker 2: talk in a lot of detail about what the actual 37 00:02:13,120 --> 00:02:18,000 Speaker 2: readout means. I don't feel remotely qualified to get into that, 38 00:02:18,520 --> 00:02:21,280 Speaker 2: and I also don't think are either muddling through it 39 00:02:21,400 --> 00:02:24,240 Speaker 2: or just reading somebody else's definition word for word would 40 00:02:24,360 --> 00:02:28,000 Speaker 2: actually add to the history of this in a way 41 00:02:28,000 --> 00:02:31,880 Speaker 2: that would sort of add to it. For like typical 42 00:02:32,680 --> 00:02:38,440 Speaker 2: non cardiologist, non physician type people. So the heart is 43 00:02:38,480 --> 00:02:42,440 Speaker 2: a muscle and its beats are controlled by electrical activity 44 00:02:42,560 --> 00:02:46,160 Speaker 2: generated in the sinus node also called the cinoaitrial node 45 00:02:46,560 --> 00:02:49,440 Speaker 2: that's a part of the heart. An electric cardiogram is 46 00:02:49,480 --> 00:02:53,320 Speaker 2: a non invasive test that measures this electrical activity using 47 00:02:53,360 --> 00:02:56,080 Speaker 2: electrodes placed on the skin, which are connected to an 48 00:02:56,080 --> 00:03:02,080 Speaker 2: electric cardiograph or ECG machine with leadwire. The machine translates 49 00:03:02,160 --> 00:03:05,520 Speaker 2: those electrical signals into a graphical representation of a wave 50 00:03:05,880 --> 00:03:08,919 Speaker 2: and that is immediately available to be read and interpreted. 51 00:03:08,960 --> 00:03:10,880 Speaker 2: With today's technology. 52 00:03:10,800 --> 00:03:14,680 Speaker 1: This is typically a fast, painless test, although people who 53 00:03:14,720 --> 00:03:18,000 Speaker 1: are sensitive to adhesives or to the material the electrodes 54 00:03:18,040 --> 00:03:22,640 Speaker 1: are made from can experience some irritation. That happened to 55 00:03:22,639 --> 00:03:24,760 Speaker 1: me the first time I ever had one, yes, say 56 00:03:24,840 --> 00:03:27,919 Speaker 1: something years ago, but not with this one most recently. 57 00:03:29,280 --> 00:03:33,040 Speaker 1: This technology grew from both the study of electricity and 58 00:03:33,120 --> 00:03:35,920 Speaker 1: the study of anatomy and physiology, and then all that, 59 00:03:36,040 --> 00:03:39,360 Speaker 1: of course, started way before the end of the nineteenth 60 00:03:39,400 --> 00:03:43,600 Speaker 1: century when the first ECGs were invented. People have been 61 00:03:43,760 --> 00:03:48,480 Speaker 1: observing phenomena like static electricity and lightning since before the 62 00:03:48,480 --> 00:03:52,480 Speaker 1: start of recorded history, and While different societies have had 63 00:03:52,520 --> 00:03:56,840 Speaker 1: taboos around things like dissections and autopsies, people have also 64 00:03:56,960 --> 00:04:01,200 Speaker 1: been doing them and examining hearts and other muscles for 65 00:04:01,320 --> 00:04:05,800 Speaker 1: thousands of years. The word electricity was first used in 66 00:04:05,800 --> 00:04:09,160 Speaker 1: writing by English polymath and member of Parliament Sir Thomas 67 00:04:09,200 --> 00:04:14,160 Speaker 1: Brown in sixteen forty six in his Pseudodoxia Epidemica, or 68 00:04:14,360 --> 00:04:19,120 Speaker 1: Enquiries into Very Many Received Tenets and Commonly Presumed Truths. 69 00:04:19,920 --> 00:04:21,680 Speaker 1: This is a book that he wrote to try to 70 00:04:21,720 --> 00:04:26,920 Speaker 1: correct an assortment of superstitions and commonly held misinformation. It's 71 00:04:26,960 --> 00:04:29,960 Speaker 1: actually arranged into seven books, and as an example, the 72 00:04:30,080 --> 00:04:34,599 Speaker 1: third book is devoted to dispelling misinformation about animals, including 73 00:04:34,640 --> 00:04:38,440 Speaker 1: the idea that elephants don't have joints, that beavers escape 74 00:04:38,520 --> 00:04:42,320 Speaker 1: hunters by biting off their testicles, although who could blame them, 75 00:04:42,400 --> 00:04:47,960 Speaker 1: and that the ostrich digestith iron. Brown's descriptions of electricity 76 00:04:48,000 --> 00:04:52,120 Speaker 1: are focused on static electricity, including the ability of materials 77 00:04:52,200 --> 00:04:56,400 Speaker 1: like amber and jet to attract lightweight objects after being rubbed. 78 00:04:57,240 --> 00:05:01,039 Speaker 1: Similar words like electric and electric were coined in the 79 00:05:01,080 --> 00:05:02,719 Speaker 1: seventeenth century as well. 80 00:05:04,000 --> 00:05:06,880 Speaker 2: I was extremely delighted by just the table of contents 81 00:05:07,000 --> 00:05:13,320 Speaker 2: at this book. In the sixteen sixties, Dutch naturalist Yon 82 00:05:13,400 --> 00:05:18,600 Speaker 2: Swammerdam carried out experiments on frogs and other animals. This 83 00:05:18,640 --> 00:05:23,200 Speaker 2: included using his scalpel or another instrument to stimulate nerve 84 00:05:23,279 --> 00:05:27,520 Speaker 2: tissue during dissections, and that would cause the corresponding muscles 85 00:05:27,520 --> 00:05:31,760 Speaker 2: to twitch. He believed that these muscular contractions were caused 86 00:05:31,760 --> 00:05:36,839 Speaker 2: by the flow of animal spirits or nervous fluid. There's 87 00:05:36,960 --> 00:05:41,120 Speaker 2: some debate about whether these experiments involved electricity. Some of 88 00:05:41,160 --> 00:05:44,320 Speaker 2: his instruments were made of multiple different metals, and they 89 00:05:44,360 --> 00:05:48,760 Speaker 2: had voltage differences that could have produced a small current 90 00:05:49,560 --> 00:05:52,640 Speaker 2: if that's the case, though he definitely was not aware 91 00:05:52,920 --> 00:05:54,320 Speaker 2: that that was what was happening. 92 00:05:55,120 --> 00:05:58,760 Speaker 1: About one hundred years later, researchers were studying animals like 93 00:05:58,880 --> 00:06:03,800 Speaker 1: electric rays also called common torpedoes, as well as electric eels. 94 00:06:04,600 --> 00:06:08,719 Speaker 1: One was American scientist and spy Edward Bancroft, who described 95 00:06:08,760 --> 00:06:11,760 Speaker 1: torpedoes and their ability to shock people in his book 96 00:06:12,040 --> 00:06:15,960 Speaker 1: An Essay on the Natural History of Guiana. His description 97 00:06:16,200 --> 00:06:20,000 Speaker 1: didn't really line up with how people understood electrical charges. 98 00:06:20,040 --> 00:06:23,640 Speaker 1: At this point, it was known that metal could conduct electricity, 99 00:06:23,680 --> 00:06:27,000 Speaker 1: but that glass and sealing wax couldn't, and the idea 100 00:06:27,080 --> 00:06:30,400 Speaker 1: of electricity coming from a living thing just seemed bizarre. 101 00:06:31,240 --> 00:06:34,560 Speaker 1: Earlier descriptions of these animals had concluded that the jolts 102 00:06:34,560 --> 00:06:38,560 Speaker 1: they produced were physical, not electrical, but Bancroft did some 103 00:06:38,640 --> 00:06:42,080 Speaker 1: experiments showing that the shock from a torpedo was similar 104 00:06:42,120 --> 00:06:44,400 Speaker 1: to the electrical charge that could be stored in a 105 00:06:44,480 --> 00:06:45,120 Speaker 1: Leiden jar. 106 00:06:46,440 --> 00:06:50,800 Speaker 2: In seventeen seventy two, British scientist John Walsh worked off 107 00:06:50,839 --> 00:06:55,679 Speaker 2: of Bancroft's ideas to experiment with electric rays and found 108 00:06:55,680 --> 00:06:59,440 Speaker 2: that it was possible to direct the shocks these rays 109 00:06:59,480 --> 00:07:03,839 Speaker 2: produced through a circuit of four people. He wrote letters 110 00:07:03,839 --> 00:07:07,080 Speaker 2: about this to Benjamin Franklin, and he was awarded the 111 00:07:07,200 --> 00:07:10,440 Speaker 2: Royal Society's Coply Medal for his paper on the torpedo 112 00:07:10,640 --> 00:07:14,920 Speaker 2: in seventeen seventy three. Then, in seventeen seventy five, Danish 113 00:07:14,960 --> 00:07:19,960 Speaker 2: physician and veterinarian Peter Christian Ablegard used electrical shocks to 114 00:07:20,200 --> 00:07:25,160 Speaker 2: quote render lifeless a bird and then to revive it. 115 00:07:25,160 --> 00:07:30,720 Speaker 2: Italian researcher Luigi Galvani experimented with frogs, and on September twentieth, 116 00:07:30,760 --> 00:07:34,120 Speaker 2: seventeen eighty six, he wrote, quote, I had dissected and 117 00:07:34,200 --> 00:07:37,000 Speaker 2: prepared a frog in the usual way, and while I 118 00:07:37,120 --> 00:07:39,880 Speaker 2: was attending to something else, I laid it on a 119 00:07:39,920 --> 00:07:43,760 Speaker 2: table on which stood an electrical machine, at some distance 120 00:07:43,800 --> 00:07:48,800 Speaker 2: from its conductor and separated from it by a considerable space. Now, 121 00:07:48,880 --> 00:07:53,239 Speaker 2: when one of the persons present touched accidentally and lightly 122 00:07:53,560 --> 00:07:56,040 Speaker 2: the inner cural nerves of the frog with the point 123 00:07:56,080 --> 00:07:58,800 Speaker 2: of a scalpel, all the muscles of the legs seemed 124 00:07:58,800 --> 00:08:01,880 Speaker 2: to contract again an again, as if they were affected 125 00:08:01,920 --> 00:08:07,800 Speaker 2: by powerful cramps. Other eighteenth century researchers experimented with using 126 00:08:07,840 --> 00:08:12,760 Speaker 2: electricity to revive the apparently dead, including English surgeon Charles 127 00:08:12,880 --> 00:08:17,560 Speaker 2: Kite and Italian scientist Alessandro Volta. It's possible that these 128 00:08:17,600 --> 00:08:21,320 Speaker 2: experiments were one of the inspirations for Mary Shelley's Frankenstein 129 00:08:21,720 --> 00:08:23,160 Speaker 2: or the modern Prometheus. 130 00:08:24,080 --> 00:08:28,120 Speaker 1: In the early nineteenth century, Johann Schwager of Nuremberg developed 131 00:08:28,160 --> 00:08:32,680 Speaker 1: the first galvanometer that was an instrument to measure electrical current, 132 00:08:32,760 --> 00:08:37,080 Speaker 1: which was later named in honor of Luigi Galvani. Around 133 00:08:37,120 --> 00:08:41,480 Speaker 1: the same time, Danish physicist Hans Christian Ersted noted that 134 00:08:41,559 --> 00:08:44,800 Speaker 1: it was possible for changes in electrical current to deflect 135 00:08:44,920 --> 00:08:49,960 Speaker 1: a compass needle showing a connection between electricity and magnetism. 136 00:08:50,400 --> 00:08:54,280 Speaker 1: By the eighteen thirties and forties, researchers were using galvanometers 137 00:08:54,280 --> 00:08:58,320 Speaker 1: to study electrical activity in animals, not just ones that 138 00:08:58,360 --> 00:09:02,640 Speaker 1: could produce an obvious chart like electric raisin eels. This 139 00:09:02,760 --> 00:09:07,880 Speaker 1: included Italian physicist Leopoldo Nobili. In eighteen thirty four, he 140 00:09:08,040 --> 00:09:12,240 Speaker 1: developed an instrument called an astatic galvanometer to detect very 141 00:09:12,280 --> 00:09:15,439 Speaker 1: small electric currents, and he used it to detect a 142 00:09:15,520 --> 00:09:19,520 Speaker 1: current between a frog's limbs and spinal cord. In eighteen 143 00:09:19,600 --> 00:09:24,480 Speaker 1: forty two, Carlo Matiucci used Nobili's invention to detect electrical 144 00:09:24,559 --> 00:09:26,520 Speaker 1: currents in the hearts of pigeons. 145 00:09:27,679 --> 00:09:31,640 Speaker 2: Within a decade, researchers had started to realize a connection 146 00:09:31,800 --> 00:09:36,520 Speaker 2: between the electrical activity of the heart and irregular heartbeats, 147 00:09:36,720 --> 00:09:42,480 Speaker 2: specifically ventricular fibrillation. Maritz Haffe described this in eighteen fifty 148 00:09:42,640 --> 00:09:46,079 Speaker 2: following experiments in the lab of his teacher Karl Ludwig, 149 00:09:46,600 --> 00:09:50,640 Speaker 2: he was able to induce ventricular fibrillation in dogs by 150 00:09:50,640 --> 00:09:54,560 Speaker 2: exposing their hearts to electrical currents. A few years later, 151 00:09:54,720 --> 00:09:58,600 Speaker 2: in eighteen fifty six, Albert von Kolliger and Heinrich Mueller 152 00:09:59,240 --> 00:10:03,560 Speaker 2: detected electionlectrical activity in frog hearts in a lab in Germany, 153 00:10:04,120 --> 00:10:08,200 Speaker 2: discovering that the heart generated electricity and that there was 154 00:10:08,240 --> 00:10:11,480 Speaker 2: a rhythm to it that was associated with each beat. 155 00:10:12,480 --> 00:10:16,960 Speaker 1: Much of this animal research involved dissections or vivisections, and 156 00:10:17,080 --> 00:10:21,959 Speaker 1: scientists were detecting electrical signals from exposed skeletal muscles and hearts. 157 00:10:22,520 --> 00:10:25,679 Speaker 1: But by the late nineteenth century people started figuring out 158 00:10:25,679 --> 00:10:29,920 Speaker 1: ways to record the heart's electrical activity from outside the body. 159 00:10:30,480 --> 00:10:32,960 Speaker 1: We'll talk more about that after a sponsor break. 160 00:10:42,720 --> 00:10:47,599 Speaker 2: In eighteen sixty nine, Scottish electrical engineer Alexander Muirhead was 161 00:10:47,679 --> 00:10:51,880 Speaker 2: working at Saint Bartholomew's Hospital in London and he found 162 00:10:51,880 --> 00:10:55,199 Speaker 2: a way to record the electrical rhythm of a patient's 163 00:10:55,280 --> 00:10:59,480 Speaker 2: beating heart. He attached an electrode to the patient's wrist 164 00:10:59,600 --> 00:11:03,200 Speaker 2: and the case connected that to a siphon recorder. This 165 00:11:03,360 --> 00:11:07,520 Speaker 2: recorder was developed by William Thompson as a receiver for 166 00:11:07,600 --> 00:11:12,240 Speaker 2: the extremely weak electrical signals that had traveled along underwater 167 00:11:12,360 --> 00:11:16,400 Speaker 2: telegraph cables. That used a glass tube with an increas 168 00:11:16,440 --> 00:11:19,200 Speaker 2: of war at one end, which swayed back and forth 169 00:11:19,280 --> 00:11:24,120 Speaker 2: in response to positive and negative electrical signals. This created 170 00:11:24,160 --> 00:11:29,840 Speaker 2: a continuous wavering line on a recording paper. For telegraph cables, 171 00:11:29,920 --> 00:11:34,480 Speaker 2: that wavering line represented the dots and dashes of Morse code, 172 00:11:34,920 --> 00:11:38,040 Speaker 2: but in muir head set up, it represented the electrical 173 00:11:38,120 --> 00:11:42,560 Speaker 2: rhythm of the heart. This was most likely the first 174 00:11:42,679 --> 00:11:46,600 Speaker 2: ever recording of electrical activity in the heart of a 175 00:11:46,760 --> 00:11:50,960 Speaker 2: human patient, but Muirhead did not publicize this work. 176 00:11:51,760 --> 00:11:54,400 Speaker 1: The next major step in the development of the electric 177 00:11:54,400 --> 00:11:59,120 Speaker 1: cardiogram was the work of British physiologist Augustus Desiree Waller 178 00:11:59,200 --> 00:12:03,200 Speaker 1: at Saint Mary's Hospital, London in eighteen eighty seven. He 179 00:12:03,320 --> 00:12:07,400 Speaker 1: used a capillary electrometer developed by Gabriel Lippmann to record 180 00:12:07,440 --> 00:12:12,760 Speaker 1: electrical activity from patient's hearts. This electrometer was made out 181 00:12:12,800 --> 00:12:16,720 Speaker 1: of a glass tube filled with mercury. One end of 182 00:12:16,760 --> 00:12:20,400 Speaker 1: the tube was formed into a tiny capillary that could 183 00:12:20,440 --> 00:12:25,320 Speaker 1: be submerged in diluted sulfuric acid. There was an electrical 184 00:12:25,400 --> 00:12:29,280 Speaker 1: potential difference between the mercury and the sulfuric acid, so 185 00:12:29,360 --> 00:12:32,320 Speaker 1: when this setup was connected to the patient's body through 186 00:12:32,400 --> 00:12:37,040 Speaker 1: electrodes and leads, the curved surface of the mercury in 187 00:12:37,120 --> 00:12:40,520 Speaker 1: the tube or the meniscus would shift in response to 188 00:12:40,559 --> 00:12:45,280 Speaker 1: the current from the patient's heart. These shifts were tiny, 189 00:12:45,760 --> 00:12:51,439 Speaker 1: so they were projected onto photosensitive paper using a projecting microscope. 190 00:12:51,559 --> 00:12:56,320 Speaker 1: British physiologist John Burdon Sanderson and Frederick Page had used 191 00:12:56,360 --> 00:12:59,880 Speaker 1: a similar device to record a two phase current in 192 00:13:00,160 --> 00:13:05,439 Speaker 1: frog heartbeats in eighteen seventy eight. Waller called this a cardiograph, 193 00:13:05,559 --> 00:13:08,320 Speaker 1: and he did a number of experiments with it, including 194 00:13:08,400 --> 00:13:12,440 Speaker 1: working with different numbers of leads, sometimes a single lead, 195 00:13:12,640 --> 00:13:17,679 Speaker 1: sometimes two, and eventually five. Those five electrodes were on 196 00:13:17,800 --> 00:13:20,880 Speaker 1: all four of the patient's limbs and one in their mouth. 197 00:13:21,720 --> 00:13:24,760 Speaker 1: He used electrodes strapped to the surface of the patient's body, 198 00:13:24,800 --> 00:13:27,800 Speaker 1: as well as jars of saline solution that acted as 199 00:13:27,840 --> 00:13:31,679 Speaker 1: electrodes for the hands and feet. He also did demonstrations 200 00:13:31,679 --> 00:13:34,720 Speaker 1: of this concept with his dog, Jimmy, who would stand 201 00:13:34,760 --> 00:13:38,520 Speaker 1: with two of his feet in jars of saline. Jimmy 202 00:13:38,600 --> 00:13:40,680 Speaker 1: was reportedly a very patient dog. 203 00:13:42,800 --> 00:13:46,160 Speaker 2: While Waller was able to record electrical signals from the 204 00:13:46,280 --> 00:13:50,520 Speaker 2: heart with the capillary electrometer, he didn't really think this 205 00:13:50,720 --> 00:13:54,400 Speaker 2: was going to be useful in clinical practice. He eventually 206 00:13:54,480 --> 00:13:57,000 Speaker 2: came to see more value in it, but earlier on 207 00:13:57,080 --> 00:13:59,920 Speaker 2: he's quoted as saying he didn't imagine that it would 208 00:14:00,120 --> 00:14:04,520 Speaker 2: thee extensive use in hospitals quote that can be at 209 00:14:04,640 --> 00:14:08,080 Speaker 2: most of rare and occasional use to afford a record 210 00:14:08,120 --> 00:14:11,240 Speaker 2: of some rare anomaly of cardiac action. 211 00:14:12,320 --> 00:14:15,280 Speaker 1: One of the people who saw one of Waller's demonstrations 212 00:14:15,320 --> 00:14:20,080 Speaker 1: with Jimmy was Dutch physiologist VILLEM. Eintoven. He had been 213 00:14:20,080 --> 00:14:23,640 Speaker 1: born in Semarang, Java in eighteen sixty and he had 214 00:14:23,720 --> 00:14:27,760 Speaker 1: Jewish ancestry. Ancestors on his father's side had fled to 215 00:14:27,800 --> 00:14:31,840 Speaker 1: the Netherlands during the Spanish Inquisition. His father and his 216 00:14:31,880 --> 00:14:35,240 Speaker 1: grandfather were both doctors, and he earned both an MD 217 00:14:35,440 --> 00:14:39,520 Speaker 1: and a PhD from the University of Utrecht. Ethoven saw 218 00:14:39,600 --> 00:14:43,720 Speaker 1: Waller's demonstration at the International Congress of Physiology in London 219 00:14:44,120 --> 00:14:49,320 Speaker 1: in eighteen eighty seven. After seeing this demonstration, Aintoven started 220 00:14:49,360 --> 00:14:53,160 Speaker 1: working on his own device, describing it as an electro 221 00:14:53,280 --> 00:14:58,200 Speaker 1: cardiogram at the eighteen ninety three Dutch Medical Meeting. Although 222 00:14:58,280 --> 00:15:02,000 Speaker 1: Eintoven is usually credited with coining this term, he actually 223 00:15:02,000 --> 00:15:05,680 Speaker 1: gave the credit to Waller. Intoven started out with a 224 00:15:05,800 --> 00:15:10,000 Speaker 1: five lead setup similar to Waller's, but ultimately dropped the 225 00:15:10,040 --> 00:15:13,400 Speaker 1: two leads that he thought provided the lowest yield for 226 00:15:13,440 --> 00:15:16,040 Speaker 1: the signal. Those two leads were the one in the 227 00:15:16,080 --> 00:15:20,560 Speaker 1: mouth and the right leg. That left three leads for 228 00:15:20,640 --> 00:15:24,160 Speaker 1: both of the patient's hands and their left leg. All 229 00:15:24,200 --> 00:15:29,080 Speaker 1: the electrodes for the setup were buckets of saline. Inoven 230 00:15:29,160 --> 00:15:32,960 Speaker 1: studied the curves produced by this device, noticing that there 231 00:15:33,040 --> 00:15:36,880 Speaker 1: was a pattern of five deflections for each heartbeat. He 232 00:15:36,960 --> 00:15:42,239 Speaker 1: labeled these deflections ABCD, and E. He worked with mathematician 233 00:15:42,400 --> 00:15:45,360 Speaker 1: Heindrich Lorentz to create a formula that would account for 234 00:15:45,400 --> 00:15:50,040 Speaker 1: inertia and friction within the device. The resulting pattern looked 235 00:15:50,080 --> 00:15:54,280 Speaker 1: like what we see in an EKG today. Every person's 236 00:15:54,280 --> 00:15:57,200 Speaker 1: heartbeat is their own, but in a healthy heart that's 237 00:15:57,240 --> 00:15:59,960 Speaker 1: beating normally, the basic pattern is the same. 238 00:16:01,040 --> 00:16:06,880 Speaker 2: Eintoven labeled those five corrected deflections as PQRS, and T. 239 00:16:07,520 --> 00:16:10,920 Speaker 2: He probably chose p AT as the starting point because 240 00:16:10,960 --> 00:16:13,760 Speaker 2: of a tradition dating back to Renee Descartes of using 241 00:16:13,880 --> 00:16:17,440 Speaker 2: letters from the second half of the alphabet. The letters 242 00:16:17,560 --> 00:16:20,960 Speaker 2: N and O were already widely being used for other purposes. 243 00:16:21,600 --> 00:16:25,000 Speaker 2: Aintoven published a paper detailing all this in eighteen ninety 244 00:16:25,040 --> 00:16:28,200 Speaker 2: five called Form of the Human electro cardiogram. 245 00:16:29,080 --> 00:16:32,160 Speaker 1: Then Eintoven started working on developing a device with a 246 00:16:32,200 --> 00:16:36,680 Speaker 1: more sensitive galvanometer. He did this with a string galvanometer 247 00:16:37,000 --> 00:16:40,840 Speaker 1: made from a thread of quartz coated in silver. This 248 00:16:40,960 --> 00:16:44,320 Speaker 1: thread was suspended between the poles of an electromagnet, and 249 00:16:44,400 --> 00:16:48,160 Speaker 1: it shifted within the electromagnetic field in response to the 250 00:16:48,200 --> 00:16:53,360 Speaker 1: electrical signals from the heart. While this galvanometer was more sensitive, 251 00:16:53,480 --> 00:16:56,720 Speaker 1: its movements were still teeny tiny, so they had to 252 00:16:56,720 --> 00:17:00,560 Speaker 1: be magnified and projected onto a running sheet of photographic film. 253 00:17:01,240 --> 00:17:04,040 Speaker 1: He presented this device for the first time in nineteen 254 00:17:04,080 --> 00:17:04,480 Speaker 1: oh one. 255 00:17:05,480 --> 00:17:08,040 Speaker 2: This was pretty similar to a device that had been 256 00:17:08,160 --> 00:17:13,000 Speaker 2: created by French engineer and aviator Clement Adair for receiving 257 00:17:13,080 --> 00:17:17,320 Speaker 2: underwater transmissions through wires. It seems like these two men 258 00:17:17,480 --> 00:17:20,840 Speaker 2: each came up with their devices independently of one another, 259 00:17:21,000 --> 00:17:24,720 Speaker 2: but Intoven later did acknowledge Adair's similar work. 260 00:17:25,800 --> 00:17:29,760 Speaker 1: Although Eintoven's string galvanometer was more sensitive and precise than 261 00:17:29,760 --> 00:17:33,080 Speaker 1: the capillary device had been, that did not mean that 262 00:17:33,160 --> 00:17:36,680 Speaker 1: it was small or easy to use. It weighed more 263 00:17:36,680 --> 00:17:40,399 Speaker 1: than six hundred sixty pounds or three hundred kilograms, and 264 00:17:40,480 --> 00:17:44,840 Speaker 1: it took up two rooms It required a large electromagnet 265 00:17:44,880 --> 00:17:47,800 Speaker 1: which had to be continually cooled with flowing water to 266 00:17:47,920 --> 00:17:52,240 Speaker 1: keep it from overheating, and it required five people to operate. 267 00:17:53,000 --> 00:17:56,159 Speaker 1: So by nineteen oh three Etoven was working on making 268 00:17:56,280 --> 00:17:59,560 Speaker 1: a commercial version of this device which could actually be 269 00:17:59,680 --> 00:18:05,400 Speaker 1: used and clinical medicine. This was not really that would 270 00:18:05,440 --> 00:18:08,159 Speaker 1: be a long process and in the meantime it just 271 00:18:08,280 --> 00:18:11,520 Speaker 1: it wasn't possible to move his device from the laboratory, 272 00:18:11,560 --> 00:18:14,080 Speaker 1: where it took up two rooms, to a hospital where 273 00:18:14,119 --> 00:18:17,760 Speaker 1: it could be used with patients more easily. His colleague 274 00:18:17,800 --> 00:18:21,280 Speaker 1: Johannes Bosha made a suggestion, and that was to connect 275 00:18:21,320 --> 00:18:24,760 Speaker 1: to the electro cardiogram at the lab to the academic 276 00:18:24,840 --> 00:18:29,000 Speaker 1: hospital in Leiden, roughly a mile or fifteen hundred meters away. 277 00:18:29,960 --> 00:18:33,119 Speaker 1: They did this with a telephone line. Patients in the 278 00:18:33,200 --> 00:18:35,840 Speaker 1: hospital placed both of their arms and one of their 279 00:18:35,920 --> 00:18:40,000 Speaker 1: legs in buckets of saline, with those buckets acting as electrodes, 280 00:18:40,560 --> 00:18:43,440 Speaker 1: and they were connected to a telephone line that carried 281 00:18:43,560 --> 00:18:47,080 Speaker 1: their electrical signal to the galvanometer in the lab. 282 00:18:48,160 --> 00:18:51,080 Speaker 2: Then they could read the electro cardiogram in the lab 283 00:18:51,119 --> 00:18:54,200 Speaker 2: almost a mile away. On March twenty second of nineteen 284 00:18:54,200 --> 00:18:58,040 Speaker 2: oh five, the first telecardiogram was transmitted from the hospital. 285 00:18:58,880 --> 00:19:03,639 Speaker 1: Einthoven published a paper called Leutelecardiogram in nineteen oh six. 286 00:19:04,280 --> 00:19:07,720 Speaker 1: This work detailed a number of arrhythmias and other issues 287 00:19:07,720 --> 00:19:10,639 Speaker 1: that could be detected by examining the results of an 288 00:19:10,680 --> 00:19:18,440 Speaker 1: electro cardiogram, including mitral insufficiency, left ventricular hypertrophy, premature ventricular contractions, 289 00:19:18,560 --> 00:19:23,840 Speaker 1: and atrial flutter. By this point, Cambridge Scientific Instrument Company 290 00:19:23,880 --> 00:19:28,040 Speaker 1: of London had developed a commercial version of the Eintoven 291 00:19:28,200 --> 00:19:32,040 Speaker 1: electric cardiograph, and it had sold three of them. All 292 00:19:32,080 --> 00:19:34,879 Speaker 1: three were for use in laboratory research, though not for 293 00:19:35,160 --> 00:19:39,399 Speaker 1: clinical work in human medical patients. The first purchase of 294 00:19:39,400 --> 00:19:42,520 Speaker 1: one of these machines for clinical work was in nineteen 295 00:19:42,640 --> 00:19:48,000 Speaker 1: oh eight. We'll talk about how electric cardiographs and electrocardiograms 296 00:19:48,119 --> 00:20:00,800 Speaker 1: developed from here. After another sponsor break, in. 297 00:20:00,840 --> 00:20:05,600 Speaker 2: Nineteen eleven, Cambridge Instrument Company released a table model of 298 00:20:05,680 --> 00:20:09,760 Speaker 2: William Eintoven's electro cardiograph. This one was still a lot 299 00:20:09,800 --> 00:20:13,440 Speaker 2: bigger than most of today's machines that you might see 300 00:20:13,480 --> 00:20:16,720 Speaker 2: in a doctor's office. It still required patients to sit 301 00:20:16,800 --> 00:20:18,879 Speaker 2: with both of their hands and one of their feet 302 00:20:18,960 --> 00:20:23,119 Speaker 2: in buckets of saline, so it was still relatively cumbersome, 303 00:20:23,160 --> 00:20:26,120 Speaker 2: but it was way more compact than that two room, 304 00:20:26,280 --> 00:20:30,080 Speaker 2: six hundred pound original version, and doctors had also figured 305 00:20:30,119 --> 00:20:33,359 Speaker 2: out all kinds of conditions and abnormalities that could be 306 00:20:33,400 --> 00:20:37,720 Speaker 2: detected and diagnosed through the patterns in an electro cardiogram. 307 00:20:38,200 --> 00:20:41,159 Speaker 2: Doctors and hospitals were a little slower to adopt this 308 00:20:41,280 --> 00:20:44,440 Speaker 2: technology than they had been with the first X ray machines, 309 00:20:44,800 --> 00:20:47,960 Speaker 2: but by the time this table model was introduced, electric 310 00:20:47,960 --> 00:20:51,840 Speaker 2: cardiograms were starting to be regarded as critical to cardiac care. 311 00:20:52,720 --> 00:20:55,280 Speaker 2: We talked about the development of X rays in our 312 00:20:55,320 --> 00:20:58,800 Speaker 2: episode on mimography on January thirty first, twenty twenty four, 313 00:20:59,200 --> 00:21:01,520 Speaker 2: and the modern blood pressure cuff in our episode on 314 00:21:01,640 --> 00:21:06,040 Speaker 2: hypertension on August first, twenty twenty two. X ray machines, 315 00:21:06,080 --> 00:21:09,679 Speaker 2: blood pressure cuffs, and electric cardiograms were all developed and 316 00:21:09,800 --> 00:21:13,240 Speaker 2: refined around the turn of the twentieth century, and together 317 00:21:13,400 --> 00:21:16,679 Speaker 2: they were critical to the development of cardiology as a 318 00:21:16,720 --> 00:21:21,680 Speaker 2: specific medical field. I've also realized these are three episodes 319 00:21:21,760 --> 00:21:24,960 Speaker 2: from our catalog, including this one, all inspired by my 320 00:21:25,080 --> 00:21:31,680 Speaker 2: own medical experiences. In nineteen twelve, Welsh cardiologist Thomas Lewis 321 00:21:31,720 --> 00:21:36,040 Speaker 2: delivered a lecture at University College Hospital titled on the 322 00:21:36,080 --> 00:21:42,920 Speaker 2: evidences of Auricular Fibrillation Treated Historically. He described various arrhythmias 323 00:21:43,000 --> 00:21:47,040 Speaker 2: as clearly visible and recognizable in the waves of an 324 00:21:47,080 --> 00:21:51,720 Speaker 2: electro cardiogram, including fibrillations that is, a heart that's fluttering 325 00:21:51,800 --> 00:21:55,320 Speaker 2: or twitching in an unsynchronized way rather than beating in 326 00:21:55,359 --> 00:21:59,560 Speaker 2: a regular pattern. He also discussed the examination of a 327 00:21:59,640 --> 00:22:03,760 Speaker 2: horse that showed evidence of atrial fibrillation due to heart disease, 328 00:22:04,600 --> 00:22:08,440 Speaker 2: not something that had been induced in the horse through experimentation, 329 00:22:08,600 --> 00:22:10,320 Speaker 2: which had been the case in some of the other 330 00:22:10,400 --> 00:22:15,000 Speaker 2: animal research. He found that the waves from the horse's 331 00:22:15,080 --> 00:22:17,920 Speaker 2: heart were basically the same as that of a human's, 332 00:22:18,000 --> 00:22:21,760 Speaker 2: and he confirmed that the heart really was in atrial 333 00:22:21,800 --> 00:22:25,800 Speaker 2: fibrillation by actually looking at it during a surgical examination. 334 00:22:26,920 --> 00:22:30,080 Speaker 2: Lewis was a regular correspondent with Einthoven, and he was 335 00:22:30,160 --> 00:22:33,840 Speaker 2: also building on the work of Scottish cardiologist James Mackenzie, 336 00:22:34,080 --> 00:22:37,880 Speaker 2: who developed a polygraph machine that traced patient's pulses at 337 00:22:37,880 --> 00:22:41,560 Speaker 2: the wrist and neck, which could also show evidence of arrhythmias. 338 00:22:42,400 --> 00:22:45,760 Speaker 2: This was simpler than the polygraph machines that supposedly work 339 00:22:45,760 --> 00:22:50,680 Speaker 2: as light detectors. Today those also measure other physiological responses. 340 00:22:51,560 --> 00:22:55,160 Speaker 2: Like Augustus Waller, who we mentioned earlier, Lewis didn't really 341 00:22:55,200 --> 00:22:59,040 Speaker 2: think electric cardiograms could be very useful in clinical medicine, 342 00:22:59,600 --> 00:23:03,720 Speaker 2: but this largely because they were still pretty cumbersome. ECGs 343 00:23:03,800 --> 00:23:07,080 Speaker 2: could only capture a few seconds of activity, and since 344 00:23:07,080 --> 00:23:10,760 Speaker 2: the results were projected onto photosensitive paper, they had to 345 00:23:10,800 --> 00:23:15,080 Speaker 2: be developed before they could be interpreted. But Mackenzie's polygraph 346 00:23:15,240 --> 00:23:18,320 Speaker 2: used ink on a running roll of paper, its pulse 347 00:23:18,359 --> 00:23:23,439 Speaker 2: tracings were visible immediately. Lewis also noted that at this point, 348 00:23:23,720 --> 00:23:28,040 Speaker 2: treatment for suspected cardiac issues was the same regardless of 349 00:23:28,080 --> 00:23:31,200 Speaker 2: whether a person had been given an electric cardiogram or not. 350 00:23:32,200 --> 00:23:36,600 Speaker 2: As the technology improved, though, Lewis updated his opinion, saying, quote, 351 00:23:36,880 --> 00:23:39,960 Speaker 2: the time is at hand, if not already come, when 352 00:23:39,960 --> 00:23:43,280 Speaker 2: an examination of the heart is incomplete, if this new 353 00:23:43,359 --> 00:23:48,080 Speaker 2: method is neglected. Eindoven was still making new discoveries, and 354 00:23:48,200 --> 00:23:52,080 Speaker 2: in nineteen twelve he described his system of three leads 355 00:23:52,160 --> 00:23:56,600 Speaker 2: as an equilateral triangle that the concept known as Eindhoven's 356 00:23:56,600 --> 00:24:00,720 Speaker 2: triangle today. His written work on this it was probably 357 00:24:00,760 --> 00:24:04,080 Speaker 2: the first use in writing of the abbreviation EKG. 358 00:24:05,520 --> 00:24:10,440 Speaker 1: In nineteen eighteen, physician and professor James Herrick of Chicago 359 00:24:10,520 --> 00:24:14,159 Speaker 1: demonstrated that it was possible to use an ECG to 360 00:24:14,280 --> 00:24:19,480 Speaker 1: diagnose a myocardial infarction commonly called a heart attack. American 361 00:24:19,520 --> 00:24:24,400 Speaker 1: cardiologist Harold Party published work on diagnosing coronary artery obstructions 362 00:24:24,680 --> 00:24:29,400 Speaker 1: through electric cardiograms in nineteen twenty. In nineteen twenty four, 363 00:24:29,600 --> 00:24:33,239 Speaker 1: Villain Einsoven was awarded the Nobel Prize in Physiology or 364 00:24:33,280 --> 00:24:37,600 Speaker 1: Medicine for his discovery of the mechanism of the electro cardiogram. 365 00:24:38,119 --> 00:24:41,600 Speaker 1: The presentation speech made it clear that this award was 366 00:24:41,680 --> 00:24:47,120 Speaker 1: not only about Eindhoven's development of the electro cardiograph device. 367 00:24:47,760 --> 00:24:52,280 Speaker 1: It was also about his interpretations of the electro cardiograms, 368 00:24:52,720 --> 00:24:57,720 Speaker 1: what pqrs and T each corresponded to in a beating heart, 369 00:24:58,040 --> 00:25:02,000 Speaker 1: and how to identify so many different disorders and diseases 370 00:25:02,000 --> 00:25:05,560 Speaker 1: of the heart through the analysis and interpretation of that 371 00:25:05,680 --> 00:25:10,880 Speaker 1: one wave. Other researchers had offered other methods of interpretation, 372 00:25:11,080 --> 00:25:14,400 Speaker 1: but in the words of the award speech quote, Eintoven's 373 00:25:14,440 --> 00:25:17,960 Speaker 1: concept is the only one which has proved to be tenable. 374 00:25:18,880 --> 00:25:22,240 Speaker 1: The Nobel prize came with a monetary award that Eintoven 375 00:25:22,280 --> 00:25:25,119 Speaker 1: wanted to split with his assistant, who had worked with 376 00:25:25,200 --> 00:25:27,280 Speaker 1: him during the early years of his work and the 377 00:25:27,320 --> 00:25:31,639 Speaker 1: development of this device. His name was von Deiverd. Vondiverd 378 00:25:31,680 --> 00:25:35,679 Speaker 1: had died, though, and Eintoven instead divided the forty thousand 379 00:25:35,720 --> 00:25:39,080 Speaker 1: dollars prize money with Vondiverd's two sisters, who had been 380 00:25:39,119 --> 00:25:43,440 Speaker 1: living in poverty. Three years later, on September twenty ninth, 381 00:25:43,520 --> 00:25:48,560 Speaker 1: nineteen twenty seven, Billem Eintoven died of cancer. Also in 382 00:25:48,640 --> 00:25:53,040 Speaker 1: nineteen twenty seven, Japanese physician Tarro Takem developed the first 383 00:25:53,200 --> 00:25:58,520 Speaker 1: portable ECG machine. Two years later, the Sanborn Company of Waltham, 384 00:25:58,600 --> 00:26:03,399 Speaker 1: Massachusetts released the Sanborn Visocardiac, which was a portable version 385 00:26:03,440 --> 00:26:06,040 Speaker 1: that could print the results immediately on a roll of 386 00:26:06,080 --> 00:26:09,679 Speaker 1: paper that weighed about twenty six pounds or twelve kilograms, 387 00:26:09,680 --> 00:26:13,119 Speaker 1: and it was powered by a car battery. In nineteen 388 00:26:13,160 --> 00:26:18,240 Speaker 1: thirty four, physiologist Frank N. Wilson started working on standardizing 389 00:26:18,280 --> 00:26:22,399 Speaker 1: the use and placement of electrodes and leads. He realized 390 00:26:22,440 --> 00:26:25,439 Speaker 1: that the typical three lead system left some areas of 391 00:26:25,440 --> 00:26:28,840 Speaker 1: the heart that weren't fully represented in the ECG wave. 392 00:26:29,720 --> 00:26:33,560 Speaker 1: He added another lead, described as an exploring lead, which 393 00:26:33,600 --> 00:26:36,600 Speaker 1: could be used along with the three standard leads to 394 00:26:36,680 --> 00:26:40,040 Speaker 1: read the electrical activity of specific parts of the heart. 395 00:26:41,040 --> 00:26:45,160 Speaker 1: I couldn't pinpoint exactly when these machines moved away from 396 00:26:45,240 --> 00:26:48,160 Speaker 1: having people put their hands and feet in buckets of saline, 397 00:26:48,400 --> 00:26:51,840 Speaker 1: but these exploratory leads typically went somewhere on the chest, 398 00:26:52,000 --> 00:26:55,280 Speaker 1: so they would have used surface electrodes at some point, 399 00:26:55,280 --> 00:26:59,240 Speaker 1: though ECG's did start to use only electrodes that were 400 00:26:59,280 --> 00:27:03,800 Speaker 1: placed on the body. Today, these are usually little adhesive discs. 401 00:27:04,600 --> 00:27:08,120 Speaker 1: By the nineteen thirties, it had become clear that ECGs 402 00:27:08,200 --> 00:27:11,359 Speaker 1: could be used to help diagnose whether a patient's chest 403 00:27:11,440 --> 00:27:15,879 Speaker 1: pain had a cardiac or non cardiac cause. In nineteen 404 00:27:15,920 --> 00:27:20,520 Speaker 1: thirty five, Boston physicians Sylvester McGinn and Paul White published 405 00:27:20,560 --> 00:27:24,159 Speaker 1: work describing changes in ECG readings that were apparent in 406 00:27:24,240 --> 00:27:29,760 Speaker 1: patients who were experiencing an acute pulmonary embolism. These changes 407 00:27:29,800 --> 00:27:32,160 Speaker 1: are now known as the m again White pattern. 408 00:27:33,080 --> 00:27:36,159 Speaker 2: In nineteen thirty eight, the American Heart Association and the 409 00:27:36,200 --> 00:27:40,520 Speaker 2: Cardiac Society of Great Britain tried to standardize the placements 410 00:27:40,520 --> 00:27:44,240 Speaker 2: of that exploratory lead that had been introduced about four 411 00:27:44,320 --> 00:27:49,320 Speaker 2: years before. They recommended six specific sites, now known as 412 00:27:49,440 --> 00:27:52,320 Speaker 2: V one to V six. These are called the pre 413 00:27:52,440 --> 00:27:57,080 Speaker 2: cordial leads or the chest leads today. In nineteen forty two, 414 00:27:57,320 --> 00:28:01,719 Speaker 2: New York cardiologist Emmanuel Goldberger also worked with the number 415 00:28:01,840 --> 00:28:05,199 Speaker 2: and types of leads, and that started moving toward the 416 00:28:05,400 --> 00:28:10,080 Speaker 2: twelve lead electro cardiogram that is most commonly used today. 417 00:28:10,440 --> 00:28:13,480 Speaker 2: There are also other numbers of leads that are used 418 00:28:13,480 --> 00:28:16,800 Speaker 2: for particular purposes, but like the most common standard in 419 00:28:16,840 --> 00:28:21,920 Speaker 2: a medical setting today is twelve leads. In nineteen forty eight, 420 00:28:22,080 --> 00:28:26,480 Speaker 2: Swedish engineer Runa Emquist, who had also trained as a physician, 421 00:28:26,960 --> 00:28:31,080 Speaker 2: developed the first inkjet ECG printer. He would also go 422 00:28:31,160 --> 00:28:33,080 Speaker 2: on to be a big part of the development of 423 00:28:33,119 --> 00:28:38,240 Speaker 2: the first implantable pacemaker. By the nineteen fifties, researchers were 424 00:28:38,240 --> 00:28:43,120 Speaker 2: working on finding ways to automate ECG readings. The development 425 00:28:43,200 --> 00:28:47,480 Speaker 2: of automated readings also made other life saving developments possible, 426 00:28:47,720 --> 00:28:52,800 Speaker 2: like automated external defibrillators, which automatically diagnose arrhythmias and then 427 00:28:52,880 --> 00:28:57,200 Speaker 2: deliver shocks only when they are warranted. Today, a lot 428 00:28:57,240 --> 00:29:03,440 Speaker 2: of ECGs are automatically analyzed before being reviewed by cardiologists, internists, 429 00:29:03,520 --> 00:29:08,080 Speaker 2: primary care doctors, or other medical professionals. The automation of 430 00:29:08,160 --> 00:29:11,960 Speaker 2: ECG readings was possible thanks to the advent of computers 431 00:29:12,000 --> 00:29:15,600 Speaker 2: and microprocessors, which have continued to have a huge role 432 00:29:15,640 --> 00:29:20,080 Speaker 2: in making electric cardiograph machines much smaller and easier to use. 433 00:29:20,840 --> 00:29:25,280 Speaker 2: In nineteen fifty seven, American biophysicist Norman Jeffrey's Halter developed 434 00:29:25,280 --> 00:29:29,360 Speaker 2: the dynamic ECG, often known as the Halter ECG or 435 00:29:29,400 --> 00:29:32,520 Speaker 2: a Halter monitor, which is a portable device that can 436 00:29:32,560 --> 00:29:37,720 Speaker 2: continually monitor a patient's heart for twenty four hours or more. Today, 437 00:29:37,880 --> 00:29:41,240 Speaker 2: Holter monitors are wearable devices, weighing a couple of pounds 438 00:29:41,280 --> 00:29:44,760 Speaker 2: at most, but they initially weighed about eighty three pounds 439 00:29:44,880 --> 00:29:47,520 Speaker 2: or thirty eight kilograms and had to be worn like 440 00:29:47,600 --> 00:29:52,800 Speaker 2: a huge heavy backpack. Magneto cardiograms were introduced in nineteen 441 00:29:52,880 --> 00:29:56,640 Speaker 2: sixty three, which could record heart rhythms without the patient 442 00:29:56,760 --> 00:30:01,160 Speaker 2: needing to have electrodes on their body. Very expensive, though, 443 00:30:01,200 --> 00:30:04,880 Speaker 2: so they never really took off. That same year, American 444 00:30:04,920 --> 00:30:08,600 Speaker 2: cardiologist Robert A. Bruce developed a protocol to record a 445 00:30:08,680 --> 00:30:12,720 Speaker 2: person's cardiac signals while they did progressively more intense exercise 446 00:30:12,760 --> 00:30:16,200 Speaker 2: on a treadmill that today is known as the Bruce protocol. 447 00:30:17,080 --> 00:30:21,040 Speaker 1: And of course, ECGs have continued to evolve with changes 448 00:30:21,080 --> 00:30:24,920 Speaker 1: in technology. By nineteen ninety nine, there were twelve lead 449 00:30:24,960 --> 00:30:30,160 Speaker 1: ECGs that could send their results directly to handheld computers. Today, 450 00:30:30,280 --> 00:30:33,760 Speaker 1: there are a range of consumer ECG devices that are tiny, 451 00:30:34,280 --> 00:30:37,480 Speaker 1: everything from the ECG function on an Apple Watch to 452 00:30:37,560 --> 00:30:40,280 Speaker 1: a device the size of a credit card that communicates 453 00:30:40,320 --> 00:30:43,360 Speaker 1: with an app, to home devices that can record an 454 00:30:43,400 --> 00:30:47,560 Speaker 1: ECG and also measure a person's blood pressure. There are 455 00:30:47,680 --> 00:30:50,160 Speaker 1: pros and cons to all of these, a big one 456 00:30:50,200 --> 00:30:53,840 Speaker 1: being that while a twelve lead ECG is considered standard 457 00:30:53,840 --> 00:30:57,440 Speaker 1: in medical settings today, most of these home use models 458 00:30:57,520 --> 00:31:01,040 Speaker 1: only use one or two leads. The device or app 459 00:31:01,120 --> 00:31:05,480 Speaker 1: also typically interprets the ECG automatically and displays the results, 460 00:31:05,800 --> 00:31:09,440 Speaker 1: and that can lead to various false negatives or false positives. 461 00:31:10,760 --> 00:31:12,680 Speaker 2: If you're me and you have an Apple Watch, it 462 00:31:12,720 --> 00:31:15,560 Speaker 2: could also be that the Apple to Watch just incessantly 463 00:31:15,600 --> 00:31:19,480 Speaker 2: starts over telling you like cycling through all the things 464 00:31:19,520 --> 00:31:23,080 Speaker 2: that thinks you're doing wrong, rather than ever fully recording 465 00:31:23,200 --> 00:31:27,280 Speaker 2: the ECG I've done a lot of troubleshooting on that 466 00:31:27,280 --> 00:31:30,280 Speaker 2: that has not been successful. I also have some listener 467 00:31:30,280 --> 00:31:33,080 Speaker 2: mail that is also somewhat medical related. 468 00:31:33,120 --> 00:31:34,000 Speaker 1: It is from Edith. 469 00:31:35,320 --> 00:31:38,480 Speaker 2: Edith says, Hi, Holly and Tracy. I've been wanting to 470 00:31:38,520 --> 00:31:40,800 Speaker 2: write forever, but never had anything I thought worthy of 471 00:31:40,800 --> 00:31:43,640 Speaker 2: writing about until now. So this will probably be a 472 00:31:43,680 --> 00:31:46,040 Speaker 2: combination of things I didn't think worthy but still want 473 00:31:46,080 --> 00:31:48,880 Speaker 2: to say, and a story. First of all, I'm writing 474 00:31:48,880 --> 00:31:50,920 Speaker 2: this while in the airport on a way from Boston 475 00:31:50,960 --> 00:31:53,760 Speaker 2: to Atlanta, which I find kind of funny and coincidental. 476 00:31:54,200 --> 00:31:55,920 Speaker 2: On my drive to the airport, I was listening to 477 00:31:55,960 --> 00:31:58,880 Speaker 2: the behind the scenes following the tetanus episode. More on 478 00:31:58,960 --> 00:32:01,920 Speaker 2: this later. That's the story, first of all, as a 479 00:32:02,120 --> 00:32:05,840 Speaker 2: fifty year old former theater kid who loves to sew, 480 00:32:06,280 --> 00:32:08,680 Speaker 2: has far too much clothing and too many pairs of shoes, 481 00:32:08,680 --> 00:32:13,160 Speaker 2: and doesn't like my body to be unexpectedly exposed to unpleasantness. 482 00:32:13,200 --> 00:32:18,280 Speaker 2: Slippers for the wind, Holly, I see you now. I 483 00:32:18,320 --> 00:32:21,080 Speaker 2: have to thank you for your unintentional PSA. I just 484 00:32:21,120 --> 00:32:24,360 Speaker 2: turned fifty in April and really had not thought about vaccinations. 485 00:32:24,400 --> 00:32:26,720 Speaker 2: I mean, I still think and maybe act like I'm thirty. 486 00:32:26,760 --> 00:32:29,280 Speaker 2: But when you all mentioned that we, yes, us are 487 00:32:29,320 --> 00:32:32,720 Speaker 2: of an age where we probably only got one measle shot, 488 00:32:32,760 --> 00:32:34,440 Speaker 2: I was like, huh, I did not know that, So 489 00:32:35,240 --> 00:32:37,640 Speaker 2: now I know to ask about that at my next physical. 490 00:32:37,720 --> 00:32:41,320 Speaker 1: Thanks. Okay, okay, finally the story and the behind the scenes. 491 00:32:41,360 --> 00:32:43,920 Speaker 1: You both told stories about extra tetanus shots, so I 492 00:32:43,920 --> 00:32:46,760 Speaker 1: wanted to tell you about mine. I was in high 493 00:32:46,800 --> 00:32:49,760 Speaker 1: school in Cambridge, Massachusetts, and I did crew. Of course, 494 00:32:49,800 --> 00:32:52,680 Speaker 1: we rowed on the Charles River. One day when we 495 00:32:52,680 --> 00:32:55,080 Speaker 1: were putting the boats away, I somehow got caught in 496 00:32:55,120 --> 00:32:57,720 Speaker 1: a bad spot going around the corner and ended up 497 00:32:57,800 --> 00:33:00,280 Speaker 1: in the water. Now I know that the. 498 00:33:00,320 --> 00:33:03,720 Speaker 2: Charles isn't thought of as very clean now, but back then, 499 00:33:04,080 --> 00:33:06,520 Speaker 2: well the things you would see floating there were bad. 500 00:33:06,600 --> 00:33:09,560 Speaker 2: So I fell in and that's how I ended up 501 00:33:09,600 --> 00:33:14,320 Speaker 2: getting a tetanus booster. I will pause and say that 502 00:33:14,360 --> 00:33:17,440 Speaker 2: the title of this email is love that dirty Water, Boston, 503 00:33:17,480 --> 00:33:20,040 Speaker 2: You're My Home, which is of course a song lyric reference, 504 00:33:20,240 --> 00:33:23,360 Speaker 2: referencing also the very dirtiness of both the. 505 00:33:23,400 --> 00:33:25,360 Speaker 1: Charles and Boston Harbor at that time. 506 00:33:25,520 --> 00:33:29,720 Speaker 2: Anyway, the email continues, anyway, I don't have any pets, 507 00:33:29,760 --> 00:33:33,080 Speaker 2: so I'm attaching a variety of collected animal pictures, including 508 00:33:33,080 --> 00:33:35,959 Speaker 2: a pig video, some horses from our neighbor's farm, an 509 00:33:36,000 --> 00:33:38,440 Speaker 2: old picture of my daughter and my brother in law's 510 00:33:38,440 --> 00:33:40,600 Speaker 2: old dog, and a current picture of my daughter on 511 00:33:40,640 --> 00:33:42,760 Speaker 2: a horse wor comparison. Thank you for all you do 512 00:33:43,280 --> 00:33:45,680 Speaker 2: as a former Medford resident. For the statement at the 513 00:33:45,720 --> 00:33:49,000 Speaker 2: beginning of the latest Unearthed episode, love you guys. I 514 00:33:49,040 --> 00:33:51,520 Speaker 2: tried but failed to keep it short, Edith, Edith, I 515 00:33:51,560 --> 00:33:55,880 Speaker 2: love this email. Regarding vaccinations. We had talked in I 516 00:33:55,920 --> 00:33:58,880 Speaker 2: think behind the scenes on the show about how I 517 00:33:58,960 --> 00:34:01,520 Speaker 2: was turning fifty. I knew that I meant that meant 518 00:34:01,520 --> 00:34:03,120 Speaker 2: that I was going to need to go and get 519 00:34:03,160 --> 00:34:05,640 Speaker 2: some vaccines that are recommended at the age of fifty. 520 00:34:05,720 --> 00:34:11,640 Speaker 2: I did do that those vaccines were shingles in newmacocle pneumonia. 521 00:34:12,040 --> 00:34:14,960 Speaker 2: I did both of those at the same time, because 522 00:34:14,960 --> 00:34:18,200 Speaker 2: somehow I thought that the people saying that sometimes the 523 00:34:18,239 --> 00:34:21,759 Speaker 2: shingles vaccine can make you feel a little unwell, I 524 00:34:21,960 --> 00:34:25,719 Speaker 2: just thought that might not apply to me, because I 525 00:34:25,760 --> 00:34:28,040 Speaker 2: am not known to have ever actually had chicken box, 526 00:34:28,120 --> 00:34:30,840 Speaker 2: but it is recommended at the age of fifty. Anyway, 527 00:34:32,560 --> 00:34:37,719 Speaker 2: I did feel I felt unwell. Still much better than 528 00:34:37,760 --> 00:34:42,040 Speaker 2: getting shingles or pneumonia. So yeah, that's done. I will 529 00:34:42,040 --> 00:34:45,640 Speaker 2: need shot two of the shingles shot a little bit later. Also, 530 00:34:45,920 --> 00:34:49,040 Speaker 2: lots of great animal pictures. Man, I love horse pictures. 531 00:34:49,840 --> 00:34:53,799 Speaker 2: They're so beautiful. Are a horse and a fold just 532 00:34:54,040 --> 00:34:55,520 Speaker 2: running through a field? Oh? 533 00:34:55,560 --> 00:34:56,239 Speaker 1: Great? Is that? 534 00:34:57,040 --> 00:34:59,480 Speaker 2: I don't think I'll watch the big video while we 535 00:34:59,520 --> 00:35:00,279 Speaker 2: are sitting here. 536 00:35:01,680 --> 00:35:05,920 Speaker 1: I love a little pig action. You just reminded me 537 00:35:05,960 --> 00:35:07,560 Speaker 1: of the funniest thing I've ever seen a pig do 538 00:35:08,120 --> 00:35:12,920 Speaker 1: just now, have you ever seen a pig eat spaghetti? No, 539 00:35:14,440 --> 00:35:22,200 Speaker 1: our mutual friend, who is often prone to wacky high jinks, 540 00:35:23,120 --> 00:35:26,799 Speaker 1: briefly had a pig. I don't remember how she came 541 00:35:26,800 --> 00:35:29,560 Speaker 1: in to possession of the pig. She only had it 542 00:35:29,560 --> 00:35:31,600 Speaker 1: a brief period of time while she was rehoming it 543 00:35:31,840 --> 00:35:34,440 Speaker 1: and trying to find somebody that actually had like acreage 544 00:35:34,480 --> 00:35:36,960 Speaker 1: that they could raise a pig on. But in the meantime, 545 00:35:37,120 --> 00:35:39,919 Speaker 1: she and her amazing mother were just trying to keep 546 00:35:39,960 --> 00:35:43,320 Speaker 1: the pig fed and happy, and her mother started regularly 547 00:35:43,360 --> 00:35:46,640 Speaker 1: making the pig plates of spaghetti. It was the cutest 548 00:35:46,640 --> 00:35:49,480 Speaker 1: thing I ever saw in my life. I'm imagining what 549 00:35:49,520 --> 00:35:51,359 Speaker 1: it would look like, and it does seem very cute. 550 00:35:51,520 --> 00:35:54,200 Speaker 1: We were tiny at the time. He was still a piglet, 551 00:35:54,680 --> 00:35:56,840 Speaker 1: and so he would get the spaghetti all wound around 552 00:35:56,880 --> 00:35:58,719 Speaker 1: his snout and then try to chase it around the 553 00:35:58,760 --> 00:36:02,000 Speaker 1: house trying to get the spaghett Yeah. I wish this 554 00:36:02,080 --> 00:36:04,160 Speaker 1: were like a required thing that everybody could see in 555 00:36:04,200 --> 00:36:05,880 Speaker 1: their life because it brings so much joy. 556 00:36:06,440 --> 00:36:10,719 Speaker 2: Yeah, because I am a fan of Game Changer, I 557 00:36:10,800 --> 00:36:14,880 Speaker 2: am imagining this pig wearing a tiny hat while eating 558 00:36:15,160 --> 00:36:22,040 Speaker 2: the he was not, so thank you so much for 559 00:36:22,080 --> 00:36:25,400 Speaker 2: this email, Edith, the Charles River is a lot cleaner 560 00:36:25,440 --> 00:36:28,319 Speaker 2: than it used to be. As somebody who moved to 561 00:36:28,880 --> 00:36:33,680 Speaker 2: the Boston area from elsewhere, I have a fondness for 562 00:36:33,880 --> 00:36:36,120 Speaker 2: seeing people rowing out on the river. I don't know 563 00:36:36,160 --> 00:36:38,759 Speaker 2: how local people feel about the rowers. I'm always a 564 00:36:38,760 --> 00:36:41,799 Speaker 2: little happy when I'm usually on the tee and I 565 00:36:41,880 --> 00:36:43,879 Speaker 2: go over the bridge and I'm like, oh, people rowing 566 00:36:43,920 --> 00:36:46,040 Speaker 2: out on the river. So, if you would like to 567 00:36:46,040 --> 00:36:48,120 Speaker 2: send us a note about this or any other podcast 568 00:36:48,719 --> 00:36:52,319 Speaker 2: or a history podcast at iHeartRadio dot com, and you 569 00:36:52,320 --> 00:36:55,160 Speaker 2: can subscribe to our show on the iHeartRadio app and 570 00:36:55,400 --> 00:37:03,000 Speaker 2: anywhere else if you like to et your podcasts. Stuff 571 00:37:03,040 --> 00:37:05,800 Speaker 2: you Missed in History Class is a production of iHeartRadio. 572 00:37:06,120 --> 00:37:10,759 Speaker 2: For more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, 573 00:37:10,880 --> 00:37:12,880 Speaker 2: or wherever you listen to your favorite shows.