Pseudo-Wolff-Parkinson-White syndrome observed in a patient with Lutembacher's syndrome.

Pre-and post-operative vectorcardiograms (Frank system) and angio-cardiograms in a patient with Lutembacher's syndrome, were correlated. Preoperative vectorcardiogram showed the initial conduction delay, complete RBBB, increased QRS voltage, and open QRS loop, while left ventriculography and left atriography demonstrated the markedly posteriorly dislocated left ventricular major axis surrounded by the huge right ventricle and right atrium. Two months after operation, when the left ventricular major axis shifted from abnormally posteriorly directed to left and inferiorly, with the decreased right-sided heart chambers, the initial conduction delay disappeared with decreased QRS voltage. As these vectorcardiographic and angiocardiographic changes at the postoperative stage were parallel, we concluded that the initial conduction delay was a representation of" the pseudo-W-P-W syndrome" and due to the abnormally posteriorly dislocated left ventricular apex and the delayed excitation of the right ventricular free wall caused by the huge dilatation.