Paul M. Zoll

Interarterial coronary anastomoses in the human heart, with particular reference to anemia and relative cardiac anoxia.

In an unselected series of 1050 human hearts the coronary arteries were uniformly injected at necropsy with a standardized radiopaque mass. Interarterial coronary anastomoses were clearly demonstrated by this method and were studied with respect to their incidence and pathogenesis. Anastomoses were significantly increased in hearts with coronary artery occlusion or marked narrowing in cor pulmonale, in cardiac hypertrophy and valvular lesions, and also in normal hearts from patients with anemia. Relative cardiac anoxia is present in all these conditions; it appears to be a common underlying stimulus for the development of interarterial coronary anastomoses.

External noninvasive temporary cardiac pacing: clinical trials.

An external cardiac pacemaker-monitor has been developed that provides safe, effective noninvasive ventricular stimulation that is well tolerated in conscious patients and allows clear recognition of electrocardiographic response. The noninvasive temporary pacemaker (NTP) has now been applied in 134 patients in five hospitals. Stimulation was tolerated well in 73 of 82 conscious patients, and nine found it intolerable. The NTP was effective in evoking electrocardiographic responses in 105 patients; the 29 failures were in the presence of prolonged hypoxia or severe discomfort. The NTP was clinically useful in 82 patients: 43 of 86 were resuscitated from emergency or expected arrest, 38 of 40 were maintained in standby readiness for up to 1 month but did not require stimulation, and one of eight patients with tachycardia obtained some clinical benefit. The NTP was especially useful in 25 patients with complications or contraindications to endocardial pacing and in 57 patients in whom insertion of an endocardial electrode was avoided.

The Pathogenesis of Spontaneous Cardiac Rupture

Twenty patients with cardiac rupture were compared with suitable control groups. In each ruptured heart there was an acute coronary artery occlusion and a recent, transmural myocardial infarction which was unprotected at the site of rupture by scar or anastomotic circulation. Clinically, rupture usually occurred during the first two weeks of an acute infarction in a hypertensive patient with no previous history of old infarction or congestive failure; persisting hypertension or excessive effort usually preceded rupture. The role of an increased intraventricular pressure in the pathogenesis of cardiac rupture has therapeutic implications.

The Experimental Production of Intercoronary Arterial Anastomoses and their Functional Significance

Animal experiments were done to learn the degree of coronary narrowing required to produce the larger intercoronary collateral channels, their speed of development, and the degree of protection afforded the myocardium. Twelve or more days of 75 per cent narrowing were required to produce sufficiently rich anastomotic communications to protect the myocardium from damage, and to permit survival after superimposed acute complete occlusion. The physiologic and pathologic significance of the intercoronary collateral communications and the clinical implications in coronary artery disease are discussed.

Treatment of Stokes-Adams Disease by External Electric Stimulation of the Heart

An external cardiac pacemaker was developed and was used to stimulate the heart electrically in a series of patients with recent Stokes-Adams syncope. It resuscitated patients from attacks due to ventricular standstill; it maintained an adequate circulation during persistent ventricular standstill; and it prevented the recurrence of irregular ventricular tachycardia. Several patients have now survived for many months without recurrent syncope. Such long survivals suggest that the periods of cardiac disturbance which cause syncope may subside if the patient is kept alive during the crucial period.

Angina pectoris: A clinical and pathologic correlation

Abstract 1.1. A clinico-pathologic study of angina pectoris was carried out in a group of 848 cases in which the coronary arteries were injected and dissected by the Schlesinger technic. The group consisted of 177 patients with angina pectoris of one months duration or longer and 671 control patients without cardiac pain. 2.2. Not a single patient with angina pectoris in the entire series was found to be free of heart disease. All anginal patients had either coronary, valvular or hypertensive heart disease; 90 per cent of them had coronary narrowing or occlusion. 3.3. To clarify the relative importance of various types of heart disease in the production of angina pectoris, the incidence of angina among patients with a single form of heart disease was determined. Angina was found in 52 per cent of patients with coronary occlusion, in 16 per cent of those with valvular lesions, in 5 per cent of those with coronary narrowing and in 3 per cent of those with hypertension. 4.4. There was a clear positive correlation between the degree of coronary obstruction and the incidence of angina pectoris; among patients with occlusions of three main coronary arteries the incidence of angina pectoris was 85 per cent. 5.5. The serious prognostic import of angina pectoris in this series is evident from the mortality figures. One-third of the patients were dead within one year after the onset of angina, half were dead within two years, three-quarters were dead within five years and nine-tenths within ten years. The average duration of angina pectoris differed according to the underlying etiology: it was shorter in valvular and longer in coronary heart disease. 6.6. Congestive failure was of more serious prognostic importance than angina pectoris in coronary disease and less serious in valvular disease. 7.7. An intercurrent episode of myocardial infarction did not shorten the prognosis of a patient with angina pectoris. 8.8. The underlying mechanism of angina pectoris appears to be a relative disproportion between the requirements of the heart for blood and the supply furnished by the coronary arteries; this disproportion results in paroxysmal relative ischemia. In coronary artery disease, angina pectoris, myocardial fibrosis and intercoronary anastomoses all result from myocardial ischemia; the first is a clinical expression, the second a pathologic end result and the third a compensatory response to ischemia.

The Effects of External Electric Currents on the Heart Control of Cardiac Rhythm and Induction and Termination of Cardiac Arrhythmias

Clinically, application of electric currents to the heart has been limited to defibrillation in the operating room when the heart is exposed. In this paper technics are described for the external application of stimulating and countershock currents. They have been used successfully in man to terminate ventricular standstill from any cause and to stop ventricular tachycardia or fibrillation. For experimental purposes an additional technic has been developed for producing various cardiac arrhythmias by rapid external stimulation of the heart.

Termination of Refractory Tachycardia by External Countershock

External electric countershock has been used to terminate refractory supraventricular and ventricular tachycardia and atrial fibrillation in eight patients. General anesthesia is necessary when the patient is conscious. This technic is indicated when the patients condition is desperate or intolerable and drug therapy is ineffective, too slow, or otherwise inadvisable.

External Mechanical Cardiac Stimulation

TEMPORARY cardiac stimulation in the emergency resuscitation from cardiac arrest and in other less urgent conditions is generally applied by way of a pervenous endocardial electrode and an external...

Prevention of Ventricular Tachycardia and Fibrillation by Intravenous Isoproterenol and Epinephrine

Isoproterenol and epinephrine were given intravenously in dilute solutions to nine patients with Stokes-Adams attacks due to ventricular tachycardia and fibrillation. The drugs produced ventricular acceleration and thereby controlled the attacks. This technic proved useful for prompt, short-term prevention of seizures; for the long term, direct electric stimulation with internal pacemakers was required.