“If I have seen farther, it is by standing on the shoulders of Giants.” — Sir Isaac Newton I have been involved with cardiac catheterization and electrophysiology for almost 30 years. I started out as a biomedical technician and then gravitated into the cath lab. My first day in the lab was in January of 1979. Over the following decades, I moved from the clinical environment to industry and back again...several times. My career path almost always revolved around cardiology, so I have built up a resume that looks like a patchwork quilt of experience; this has afforded me quite a perspective — meaning, I’ve heard a lot of stories. Now that I am back in the cath lab again, I’ve become one of those veteran techs who is always telling stories about the ‘olden days.’ Therefore, whenever we get a new member or an observing student in the lab, I will invariably be called upon to give the history of catheterization. I never get tired of telling it, but my colleagues always seem to wander off whenever I begin the litany. I always start off with Werner Forssmann cathing himself in 1929, and continue on through 1985 when Andreas Gruntzig tragically joined Mason Sones, Charles Dotter and Melvin Judkins, who all coincidentally passed away that year. I usually then take them through the interdependent developments in cardiac surgery and cardiac cath and mention such giants as Alfred Blalock, C. Walton Lillehei, Denton Cooley and Michael DeBakey, Eugene Braunwald, André Cournand, Paul Dudley White, and so on. However, I have recently noticed that I have been giving short shrift to the field of electrophysiology. Maybe that is because I still think of it as a “young” field…not realizing that it has been over 25 years since the first His bundle ablation was performed. I realize I need to start working on including some of the EP giants into my spiel. In addition, now that I think of it, I see that I will have to go back to the 1950s if I want to include some of the true EP giants. Unfortunately, I cannot start off with a Forssmann-like character (who received the Nobel Prize in Medicine, by the way, for that self-cathing episode) because there is no record of anyone who has paced or defibrillated themselves...or will at least admit to it! There are probably dozens of names that belong in the pantheon of EP giants, but I am going to start with just five for now. They are not necessarily the top five; they are five from the top. So here are some of the giants in electrophysiology that I will now include in my historical review. They are all associated with firsts, so here goes: Paul Zoll, MD: First Pacemaker, 1952 This is hard to believe, but in the 1940s and 1950s, the standard treatment for cardiac arrest was open-chest cardiac massage. I mention this in my Mason Sones story because back in the day, the big fear in selective coronary angiography was asystole since one had to crack the chest open in order to treat it. When Dr. Zoll came back from serving in World War II he was taken aback at this extreme method of resuscitation. He noted that “Our cardiologists carried large jackknives and even our poor eye surgeons were taken to the dog laboratories and shown how to cut chests open under emergency conditions.” He knew that there had to be a better way, and despite resistance from his contemporaries, in 1952 he proved that he could electrically stimulate the heart to make it beat effectively. That was the good news. The bad news was that he was using AC (alternating current); it was plugged into a 110-volt wall current, used external electrodes and was asynchronous…but it still worked! The first patient lived for only 20 minutes; but the second lived for 11 months, after 52 hours of pacing. By 1956, he had a working pacemaker (the Electrodyne PM-65) that also included the first cardiac monitor, which was used clinically even though it had to be plugged into the wall. Patients could only venture as far as the extension cord, and it sometimes caused skin burns, involuntary muscle contractions and intolerable pain. If you do an online search of the Electrodyne PM-65, you will see a picture of it being used on a patient. This leads us to our next giant…a person who is an engineer, not a physician. Earl Bakken: First Portable Pacemaker, 1957 In the 1950s, Dr. C. Walton Lillihei was pioneering open-heart surgery on children with “blue baby syndrome.” His patients often needed temporary pacing after surgery, so Dr. Lillihei used Dr. Zoll’s Electrodyne PM-65. However, on October 31, 1957, one of his young patients died because of a power failure. So, the next day he contacted Mr. Bakken, who along with his brother-in-law, was operating a small medical electronic equipment support company out of their Minneapolis garage. They were among the original “biomeds,” because hospitals did not have the staff to maintain and repair their electronic equipment. Dr. Lillihei asked Earl if he could solve his pacemaker problem. Earl went back to the shop and found a circuit diagram for an electronic metronome in Popular Electronics, and within a month, he delivered a small, battery-powered pacemaker to Dr. Lillihei. It was not much bigger than a couple of decks of cards and was transistorized. Best of all, it ran on batteries. Earl went on to test and refine the device in the laboratory, and after a few more weeks, he created one suitable for use on patients. When he brought that device to Dr. Lillihei, he was astonished to learn that his original pacemaker was already in use on a patient. The name of Earl Bakken’s two-man biomed company? Combining the words “medical” and “electronic” into one word, they named their company Medtronic. Bernard Lown, MD: First Defibrillator, 1961 The practice of medicine in the 1950s was of just that — medicine. If you had a heart attack, it was treated medically. For example, ventricular fibrillation was treated with drugs. CPR involved opening the chest and performing direct cardiac massage. So Dr. Bernie Lown, who was a young cardiologist at Peter Bent Brigham Hospital in Boston, searched for a better way to convert cardiac arrhythmias. He was aware of Paul Zoll’s work (who was just across town), and knew that the heart could be electrically controlled by external means. In 1956, Zoll published a paper in which he described the successful resuscitation during open-chest surgery using a 110-volt alternating current (from a regular wall outlet) using metal paddles applied directly to the heart. However, the dangers of burns and trauma from AC were well known, so in 1959, Dr. Lown embarked on a mission to find something that was more effective and less traumatic. Through animal research, he concluded that direct current was preferable to AC. He eventually settled on an optimal, sinusoidal waveform that only lasted for a few milliseconds and became known as the “Lown waveform.” He collaborated with the American Optical Company to produce the first clinical defibrillators in 1961. The original machines were large devices in a walnut-finished casing that delivered 100 joules for direct open-heart delivery and 200 to 400 joules for transthoracic shocks. They were still in use in 1976 when I was a young biomedical engineer tech. Melvin Scheinman, MD: First Catheter Ablation, 1981 We first saw how Paul Zoll was a genius when he came up with the idea of pacing (and resuscitating) the heart electrically. However, it wasn’t until Earl Bakken and Bernie Lown made the changes from alternating to direct current that pacing and defibrillating became clinically applicable. Here is yet another interesting example in which a radically new technique is developed but then becomes transformed when the energy modality is changed. After years of work on animals, Dr. Scheinman became the first person to successfully perform His bundle ablation in humans. It was accomplished by guiding an electrode catheter across the Bundle of His and then delivering a DC charge from a defibrillator. While there were definite successes, there were also cases in which His bundle activity returned. It was thought that in those cases, the tissue was only stunned rather than deactivated. It wasn’t until the energy source was changed to radiofrequency waves (microwaves) that this became a bona fide therapy. James L. Cox, MD: First Maze Procedure, 1987 Dr. Cox is a cardiac surgeon who developed the surgical Maze technique to treat atrial fibrillation. It is performed by open-heart surgery and involves the creation of a number of precise incisions in the left and right atria. The goal is to create scar tissue lines that will either block or re-route the renegade electrical impulses associated with atrial fibrillation. It also includes the removal of the left atrial appendage. The first procedure was done in 1987, and since then, the technique has been modified so that now the Cox-Maze III procedure has become the gold standard for the treatment of atrial fibrillation. It is a safe (operative mortality ≤ 1%) and effective (98% success rate) procedure; however, because it is an open-heart operation, it is not well suited for treating the substantially large population who have debilitating atrial fibrillation. Once again there remains the promise that a modality change could lead to a wider application of this concept. With the development of atrial ablation techniques and essentially creating a “maze” by means of transvenous catheters and RF ablation, the gold standard may be accomplished without the necessity of opening the chest and going on bypass. Summary That’s it — those are my first five EP giants, and giants they were and are! As I mentioned before, I selected each one because they were all involved in “firsts.” I suggest you Google or Wiki these giants — you will find some very interesting clinical anecdotes — the type of stories I like to share with my young Padawans. You may also want to check out a wonderful article by Roberta Gordon in the Harvard University Gazette that tells the story of Bernie Lown’s first clinical application of the DC defibrillator.