Intermittent ventricular parasystolic bigeminy accompanied by reentrant ventricular extrasystoles

An extremely rare case of intermittent ventricular parasystolic bigeminy is presented, in which coexisting reentrant ventricular extrasystoles of sinus origin, showing mainly trigeminy, and those of ventricular parasystolic origin, showing a close coupling to the ventricular parasystolic beat, are demonstrated. Such a unique case has never been reported. Timely parasystolic exit block occurring just prior to the anterograde ventricular activation of the sinus impulse was considered to be of critical importance in developing the reentrant extrasystolic trigeminy.