Phono-, echo-, and electro-cardiographic correlation in the Wolff-Parkinson-White syndrome, with special reference to the split pattern of second heart sound.

Twenty-three cases with WPW syndrome were studied by means of phonocardiography, echocardiography, and electrocardiography. All cases showed the abnormal cardiac motion in echocardiography, which could be divided into 2 types; ventricular (V) type in which the posterior left ventricular wall showed the abnormal humps in the early and late systole (18 cases), and septal (S) type in which the abnormal hump was noted in the early systole in the interventricular septum (5 cases). The cases with V type echocardiogram showed either type A, B, or C, and those with S type either type B or C of ECG. All cases with V type had the splitting of second heart sound of a normal fashion and the IIA-IIP interval ranged from 0.015 to 0.08 sec with a mean of 0.0356+/-0.0157 sec. In contrast, those with S type showed either a reversed splitting of second heart sound (4 cases) or a single second heart sound (1 case), and the IIA-IIP interval ranged from 0 to--0.05 sec with a mean of --0.0250+/-0.0170 sec. No consistent relationship was noted between the ECG type and the split interval of second heart sound. There was the significant positive correlation between the IIA-IIP interval and the QRS duration in the cases with V type echocardiogram. In S type, these 2 parameters showed the significant negative correlation.