Author + information
- Received August 17, 2008
- Accepted August 22, 2008
- Published online January 13, 2009.
A 64-year-old man with 3-vessel coronary artery disease underwent coronary artery bypass surgery. The surgery was uneventful and included placement of temporary epicardial pacing leads to the atrium and ventricle. On the first post-operative day, the patient had multiple episodes of polymorphic ventricular tachycardia that resulted in hemodynamic instability and defibrillation. Careful examination of recorded electrocardiograms showed identical R-on-T epicardial pacing (arrows in image above) preceding each polymorphic ventricular tachycardia episode. A 12-lead electrocardiogram after successful defibrillation revealed a normal QT interval and no ST-segment elevation. Laboratory testing showed no electrolyte abnormalities or cardiac biomarker elevations. Interrogation of the temporary epicardial pacemaker system revealed ventricular lead undersensing that resulted in inappropriate R-on-T pacing after an extended atrioventricular delay. After discontinuation of epicardial pacing, there was no recurrence of polymorphic ventricular tachycardia or other indications for implantable cardioverter-defibrillator. He was discharged home on the fifth post-operative day.
- Received August 17, 2008.
- Accepted August 22, 2008.
- American College of Cardiology Foundation