Electrocardiographically discrete right and left ventricular QRS complexes: a case report

A patient with congestive cardiomyopathy manifested a right ventricular QRS followed after 80 msec. by a left ventricular QRS in response to a single atrial depolarization. The ventricular sequence was reversible when the left ventricle was paced directly. Virtually the entire ipsilateral ventricular ejection period occurred during diastolic filling of the contralateral ventricle. Triggered left ventricular pacing, using the right ventricular electrogram as trigger, shortened the QRSRV-QRSLV interval and resulted in a reduction of left ventricular filling pressure and a significant rise in cardiac output. These findings indicated an independent contribution of this unique form of interventricular conduction disturbance to deterioration in hemodynamic performance.