[Signal-averaged electrocardiogram in right bundle branch block patients after surgical repair for congenital heart disease].

Right bundle branch block (RBBB) type was investigated using signal-averaged electrocardiogram (SAECG) in 35 RBBB patients after surgical repair of ventricular septal defect and tetralogy of Fallot. The type of RBBB was first identified by body surface mapping; 12 patients had proximal RBBB, and 23 had peripheral RBBB. The control group consisted of 20 healthy volunteers. The following three findings were seen in most patients with proximal RBBB, and were useful for determining the type of RBBB; a filtered QRS duration equal to or longer than 160 msec, a fragmented signal number equal to or greater than 10 and the whole type of filtered QRS pattern. The sensitivity and specificity of SAECG for proximal RBBB were shown to be high. In conclusion, SAECG was found to be useful for non-invasive determination of RBBB types.