Do Not Dismiss That Wenckebach

A patient in their mid-70s with a medical history of hypertension and no known history of cardiac disease presented with recurrent syncopal attacks. An electrocardiogram (ECG) showed second-degree Mobitz type 1 (Wenckebach) AV conduction block with right bundle-branch block. The patient did not show higher levels of AV conduction disease at rest; orthostatic blood pressure and the results of additional routine cardiac evaluation were unremarkable. Hanayneh and Goel decided to assess the patient's AV conduction response to exercise. In the treadmill stress laboratory, they obtained a standing ECG before the Bruce protocol was initiated and afterwards at stage 1 of the Bruce protocol.