See Also:Biography of Paul Zoll
| August 28, 1952 Paul Zoll performs the first human clinical cardiac pacing in Boston, Massachusetts. (see "Transthoracic Cardiac Pacing" below) 
Dr. Zoll's Patient - 1952
|
| Transthoracic Cardiac Pacing 
The first transthoracic cardiac pacing was accomplished with a Thyratron physiologic stimulator designed for laboratory use. The "stimulating electrodes were attached to needles placed subcutaneously in the chest wall at points in a line transversing the ventricles." "Electric shocks 2 milliseconds in duration were given at frequencies from 25 to 600 per minute. The intensity of the shocks was increased until ventricular responses were observed." "…On August 28, 1952, because of 2 severe Stokes-Adams attacks," a 75 year old man was the "first time it was possible to keep a patient alive during a ventricular asystole…" In the discussion Dr. Zoll speculates that a simplified pulse generator might be better suited for clinical purposes and that an additional circuit permitting bursts of alternating current might possibly be able "to defibrillate the human heart across the unopened chest initially and then to arouse it from ventricular standstill by pacing." In the accompanying editorial, this article is described as "an exceedingly promising report…" Zoll PM. Resuscitation of the Heart in Ventricular Standstill by External Electric Stimulation. New Eng J Med 1952; 247: 768-771 Back to Top |
Letter to Dwight E. Harken
In a letter to Dwight E. Harken dated March 7, 1990:
"First, I would like to be known as the one who introduced the modern era of cardiac pacing with a noninvasive cardiac pacemaker to resuscitate patients from ventricular standstill. Then, in 1956 I first applied transthoracic electric shocks to terminate ventricular fibrillation in man, and also in the same year developed the first cardiac monitors for clinical use."
Photo: Paul M. Zoll with long time surgical collaborator Howard Frank.
Lasker Award
After several unsuccessful attempts to build a pulse generator, I followed Callaghan's lead and obtained a standard laboratory model of a physiologic pacemaker (Grass physiological thyratron pulse generator), which was provided through the kindness of Professor Otto Krayer, head of the pharmacology department at the Harvard Medical School. With a long wire electrode in the esophagus and a second electrode over the precordium in a dog, we were able to demonstrate that an electric stimulus would indeed arouse atrial or ventricular electrical responses and effective myocardial contractions with which cardiac arrest could be reversed and the circulation maintained.
Zoll PM. Development of Electric Control of Cardiac Rhythm. Lasker Awards. JAMA 1973; 226:881-882.
Back to Top
Vitamin B1 Deficiency in Rats
Vitamin B1 deficiency in rats and pigeons has been found to be associated with bradycardia. Because of the discrepancy between electrocardiographic findings in deficiency states attributed to vitamin B in man (beriberi, pellagra, polyneuritis) and in animals, a study was undertaken on the electrocardiographic effect of vitamin B1 deficiency on the rat heart. Nine rats were placed on diets deficient in B1. Standardized ECGs were obtained. After 3 weeks the animals exhibited marked loss of weight, neurologic, bradychardia and ECG complex changes. The heart rate gradually fell from a normal level of from 564 to 666 per minute (average 581) to from 354 to 134 (average 286). In 5 of the rats' T wave changes of high origin were observed. Increase in T wave amplitude developed in 2 animals. T wave inversion occurred in one, and questionable inversion in another. Administration of crystalline vitamin B1 abolished both the bradycardia and the ECG changes when the rate was 300 or over, but usually failed to save the animals when the rate was below this level. That changes in the ECG complexes could be abolished with crystalline vitamin B1 in animals kept in a fasting state indicates that the cardiac changes are directly related to B1 deficiency rather than to malnutrition. The results of the experiments were reported and the character of the ECG changes are consistent with those observed in human deficiency states (pellagra, polyneuritis, beriberi). The essential difference is that in man tachycardia is present in vitamin B deficiency.
Zoll PM, Weiss, S. Electrocardiographic changes in rats deficient in vitamin B1. Proc Soc Exper Biol Med 1936; 35: 259-262
Back to Top
Foreign Bodies In and Around the Heart
1. A series of 78 foreign bodies that have been removed from within, or in relation to, the thoracic great vessels is discussed. Three of these were embolic.
2. A series of 56 foreign bodies that have been removed from within or on the heart is discussed. Thirteen of these were removed from the chambers of the heart…in our series of 134 patients who have had foreign bodies removed, there have been no deaths and the men are clinically well."
Foreign bodies, shrapnel, bullets and other detritus were first routinely removed from within and about the heart during the Second World War. At war's end the heart, previously considered inviolate and too dangerous to be operated upon, was demonstrated to be approachable. The intellectual climate changed and led to the cardiac procedures of the post-war era.
Zoll later wrote: "I became interested in electrical stimulation of the heart shortly after World War II, after I had observed much of the pioneering cardiac surgery done by Dr. Dwight Harken for the removal of foreign bodies in and about the heart. The heart appeared, indeed, to be a very sensitive organ that responded readily with ventricular contractions to stimuli; arousal from ventricular standstill by appropriate stimulation should, therefore, not be difficult."
Harken DE, Zoll PM. Foreign bodies in and in relation to the thoracic blood vessels and heart. III Indications for the removal of intracardiac foreign bodies and the behavior of the heart during manipulation. Amer Heart J 1946; 32: 1-19.
Back to Top
Coronary Artery Visualization
Zoll spent 50% of his time in clinical practice. His early work with Monroe Schlesinger in injecting coronary arteries of cadaveric hearts with different colors of lead-agar mass under a pressure of 150 to 200 mm Hg, yielded useful clinical pathological correlations with untoward outcomes of coronary artery disease. The hearts were then dissected and unrolled with the coronary arteries in one plane, x-rayed and then coronary arteries dissected again. The report included 177 patients with angina pectoris and 671 controls without cardiac pain were reported. (Fig. 1: X-ray of normal control.) The authors discussed the importance of ventricular hypertrophy and spasm in provoking angina as well as the importance of collateral circulation in diminishing ischemia (Fig 2: Diagram of a heart with coronary pathology.) We should note that the Shlesinger technique was a forerunner of coronary angiography. H.L. Blumgart, a co-author in this study and Chief of Medicine at Beth Israel Hospital, Boston, encouraged and supported Zoll's interest in electrical methods of resuscitating the heart.
| Fig. 1 |
 |
| Fig. 2 |
 |
Zoll PM, Wessler S, Blumgart HL. Angina Pectoris. A Clinical and Pathological Correlation. Amer J Med 1951; 9: 331-357.
Back to Top
