Syncope and sudden death in aortic stenosis

Abstract

A correlated study was made of the clinical manifestations and the electrocardiograms of 9 adult patients with aortic stenosis before, during and after the development of syncopal seizures. In 12 other patients with aortic stenosis, the mode of sudden death was registered by the “cardiac arrest” team of the hospital. All syncopal seizures were associated with a sudden drop in blood pressure, pallor, absent pulses and heart sounds and the disappearance of the aortic murmurs with loss of consciousness. If the attacks lasted from 20 to 40 seconds, the electrocardiograms revealed a regular sinus rhythm with changes in the form and height of the QRS complexes and the S-T segments. If the attacks were longer than 40 seconds, then either standstill of the whole heart, ventricular standstill, or ventricular flutter or fibrillation were the cardiac mechanisms responsible for the syncopal attacks. These longer seizures were accompanied by twitching of the body with convulsions and incontinence of feces and urine. Long periods of apnea alternated with Cheyne-Stokes respirations, and cyanosis supervened until the return of sinus rhythm. In addition, the electrocardiograms showed changes similar to those obtained experimentally and clinically during coronary artery obstruction and diminished coronary arterial blood flow. Sudden death in such patients was found to be due to ventricular standstill, ventricular flutter or ventricular fibrillation, or a combination of these. Syncope and sudden death in patients with aortic stenosis is an expression of diminished coronary arterial blood flow as a result of acute left ventricular failure and diminished cardiac output in a diseased heart.