Atrioventricular dissociation as a cause of syncope determined by head-up tilt test

This report describes a patient with syncopal attacks in a sitting position on a reclining seat, in whom atrioventricular dissociation due to accelerated ventricular rhythm was determined to be the cause by recording of the electrocardiogram, blood pressure, and mitral and aortic Doppler flow during a 60 degree head-up tilt test.