13th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 1998

January 24-31, 1998
Marilleva, Trento, Italy

RT-32

Syncope in aortic stenosis

Peter Rakovec, Matjaz Sinkovec, Primoz Rode.
Department of Cardiology, University Medical Centre, Ljubljana, Slovenia

Introduction

Traditionally, the mechanism of syncope in aortic stenosis has been thought to be most commonly due to the reduced cerebral perfusion occurring during exertion, when arterial pressure declines consequent to systemic vasodilatation in the presence of a fixed cardiac output. Ischaemic myocardial depression leads, along with mechanical obstruction, to inappropriately low cardiac output^1,2. Syncope may also be caused by arrhythmias, eg ventricular tachycardia or fibrillation³, or by conduction abnormalities, eg atrioventricular block⁴, which is quite common in aortic stenosis. More recently, some case reports, documented by ambulatory electrocardiographic tracings, pointed out the possibility of another mechanism, ie cardioinhibitory response to stimulated left ventricular mechanoreceptors.