Circulatory Consequences of Changes in Cardiac Rhythm Produced in Patients by Transthoracic Direct-Current Shock*

Abstract

Hemodynamic measurements were made at rest and during exercise in 20 patients with heart disease before and after attempts to convert atrial arrhythmia to sinus rhythm by transthoracic direct-current shock. Conversion to normal sinus rhythm had little effect on cardiac output unless a rapid ventricular rate was lowered after conversion to sinus rhythm. The transport function of the atria in these patients with heart disease seemed to be of little importance in determining their cardiac outputs.