Exercise intolerance due to sustained atrial bigeminy with short coupling interval.

Atrial bigeminy is a supraventricular arrhythmia rarely associated with severe symptoms. We report the case of a 22-year-old woman with no prior cardiac disease presenting with exercise intolerance since several months. No apparent heart disease other than a spontaneous conducted atrial bigeminy with a short coupling interval was found. At bicycle ergometric testing, symptoms occurred, because of an inadequate increase in pulse rate, due to sustained atrial bigeminy. At electrophysiological study, an ectopic atrial focus at the right atrial septum was successfully ablated.