Study on the frequency of right bundle branch block after surgical closure of ventricular septal defect

Im, Ho Joon; Park, Jin Nyoung; Kim, Nam Su; Shin, Jeh Hoon; Seol, In Joon; Moon, Soo Ji

Abstract

The purpose of this study is to evaluate the ventricular conduction abnormalities, especially RBBB, observed electrocardiographically after surgical closure of VSD. The present study population consists of 92 patients with VSD who were surgically corrected at the Hanyang University Hospital during 6 years period from Jan. 1985 to Dec. 1990. We reviewed their clinical records including surgical notes and EKG findings before and after operations. The results of the study were as follows: 1) Male to female ratio was 1.1:1 (48:44) 2) Out of a total of 92 cases of VSD, 65cases(70.7%)were perimembranous type and 27 cases (29.3%)were subarterial type. 3) The normal preoperative EKG findings were seen in 22 patients, LVH in 21 patients, BUH in 47patients, and RVH in 3 patiens. 4) A transatrial approach was performed in 55 cases, right ventriculotomy with or without resection of muscles in right ventricle in 13 cases, and pulmonary arteriotomy alone in 24 cases. 5) The right bundle branch block after operation developed in 33 patients out of the 65 patinets with perimembranous defect and 5 patients out of the 27 patients with subarterial defects. Postoperative RBBB developed more frequently in perimembranous defect than in subarterial defect. 6) Postoperative RBBB occured in 31.8% of the patients with normal preoperative EKG findings, 23.8% with preoperative LVH, 52.1% with BVH and 66.7% with RVH. Postoperative RBBB was more frequently observed in the patients group with preoperative BVH or RVH than the patients with normal or LVH. 7) Postoperative RBBB was observed in 84.6% after right wentriculotomy, in 43.6% after right atriotomy and in 12.5% with pulmonary arteriotomy alone.