Four cases of Ebstein's anomaly are described, revealing that the clinical features permit diagnosis in the majority of instances and that cardiac catheterization affords precise confirmation of the diagnosis. The occurrence of this anomaly in acyanotic adults is pointed out, and the similarity to acquired valvular rheumatic heart disease is stressed.

An analysis of the electrocardiograms from 25 patients during reduction of body temperature and total occlusion of circulation reveals marked abnormalities in conduction and rhythmicity. Hypothermia was accompanied by slowing of the heart rate, depression of intracardiac conductivity, and by inhibition of the normal centers of impulse formation with resultant atrial arrhythmias. Circulatory occlusion during hypothermia was associated with a high incidence of ventricular arrhythmias. Changes noted in electric activity of the myocardium tended to return to normal with release of occlusion and warming of the patient.H YPOTHERMIA and circulatory occlusion are technics recently introduced to permit direct vision, open heart surgery. Observations under these conditions have revealed a high incidence of cardiac arrhythmias, with ventricular arrhythmias in particular constituting one of the major hazards of the procedure. The purpose of this paper is to describe the changes in electric activity of the heart occurring during hypothermia and circulatory occlusion. MATERIAL AND METHODSThe 25 patients whose electrocardiograms were analysed ranged in age from 3 months to 36 years. They represented one-third of the total patients undergoing cardiovascular surgery under hypothermia up to February 1955. These patients were selected for study only in that technically satisfactory electrocardiographic records were obtained throughout the procedure. Twenty-four of these patients had congenital cardiovascular disease. insufficiency. Details of the technics of hypothermic cardiovascular surgery have been presented in previous reports from this Institution.'-3 Standard lead II was employed and was constantly monitored by oscillographic observation. Frequent director-writer recordings were made throughout immersion and surgery, with continuous recording during the occlusion period. Anesthetic agents employed were ether, cyclopropane and Pentothal. Medications administered during surgery included curare, succinyl choline and prostigmine. The patients were hyperventilated throughout the operative procedure. Two of the patients were receiving digitalis and one quinidine at the time of surgery. RESULTSThe electrocardiographic changes observed during the hypothermia and circulatory occlusion are considered under the following categories. Changes in Cardiac RateProgressive slowing of the cardiac rate occurred with decreasing body temperature. This relationship of cardiac rate to temperature is shown in figures 1 and 2. A steep decline in heart rate is demonstrated in both patients in the early phase of temperature reduction, with a more gradual slowing of rate with further decrease in temperature. The rate frequently increased abruptly, coincident with a change in cardiac rhythm, particularly atrial fibrillation; however, with persistence of the newly established rhythm the rate again gradually decreased with further temperature reduction.

The effect of the intravenous administration of procaine amide in 25 patients with supraventricular arrhythmias is reported. The data, including six conversions of auricular fibrillation, indicate a pronounced effect of this drug on the auricles as well as on the heart as a whole. Special attention is directed to the finding of frequent and undesirable electrocardiographic and hypotensive effects of this drug.

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