Wide complex tachycardia in a patient with congenital heart block: What is the mechanism?
A 20‐year‐old female with a known history of congenital complete heart block and patent ductus arteriosus status post coil embolization at age 10 was admitted with dizziness and palpitations. Telemetry revealed a sustained wide complex rhythm progressing to tachycardia (WCT). Her presenting electrocardiogram (ECG), at a slower rate, is shown in Figure 1. The QRS morphology was noted to be right bundle branch block (RBBB)‐like with a rightward inferiorly directed axis. The patient then underwent a diagnostic electrophysiology study (EPS) (Figs. 2 and 3).