Permanent complete heart block following surgical correction of congenital heart disease

BACKGROUND: The risk of complete heart block (CHB) from congenital heart repairs in Ghana is unknown. This information is important for referring physicians and in pre-operative counselling of patients and facilitates the process of obtaining informed consent for such repairs. OBJECTIVES: This study was undertaken to determine the incidence of permanent post-operative CHB requiring pacemaker implantation; and the post-operative problems related to the pacemaker. DESIGN: Retrospective study design. SETTING: The National Cardiothoracic Centre (NCTC), Korle-Bu Teaching Hospital, Accra, Ghana. METHOD: Review of all patients who had intra-cardiac repair of congenital heart disease known to predispose to post-operative complete heart block from January 1993 to December 2008 was carried out with computation of the frequency of complete heart block according to the intra-operative diagnoses. RESULTS: Six out of 242 patients (2.5%) developed permanent post-operative CHB. All underwent closure of a large perimembranous ventricular septal defect (VSD) either as an isolated defect (2 of 151 or 1.3%) or in the setting of conotruncal anomalies (4 of 73 or 5.5%). The dominant parental concern relating to the implanted device was the financial implications of future multiple surgeries to replace a depleted pulse generator. CONCLUSION: Permanent post-operative complete heart block occurred in 1.3% of patients undergoing VSD repair and 5.5% of those undergoing repair of conotruncal anomalies (Fallot's tetralogy). The dominant anatomic risk factor was a large perimembranous VSD as an isolated defect or as part of a conotruncal anomaly. Permanent pacemaker implantation in this setting is attended by a low morbidity.