Pacing in patients with congenital heart disease: part 1

The vast majority of patients requiring pacemaker or defibrillator implantation have structurally normal hearts and patients with congenital cardiac abnormalities constitute only a small proportion. The latter can be divided into two groups. The first includes those with undiscovered congenital abnormalities, which do not give rise to symptoms or obvious physical signs, such as dextrocardia, persistent left-sided superior vena cava, atrial septal defect and patent foramen ovale. The second group includes those who are known to have structural cardiac abnormalities, such as Ebstein’s anomaly, ventricular septal defect, transposition of great arteries, tetralogy of Fallot and tricuspid atresia, and some patients will have already undergone corrective cardiac surgery. These patients require special consideration before proceeding to the pacing theatre. In particular, the operator will need to know whether a transvenous approach is feasible, what problems might be encountered during lead implantation and how to seek the best and most stable of lead positions.