A 63-year-old man presents to the cardiac catherization lab six days after an acute myocardial infarction. His symptoms initially had improved with fibrinolysis, however he had recurrent chest pain after 24 hours, and developed complete heart block, requiring pacemaker implantation. The following ECG was recorded on arrival in the cardiac catheterization lab:

• Sinus rhythm with complete heart block
• Electronic ventricular pacemaker, with paced ventricular rhythm, 66/min

After injection of the left anterior descending artery showing 75% proximal stenosis, the patient developed an arrhythmia and lost consciousness:

• Sinus rhythm with complete heart block
• Paced ventricular rhythm with premature ventricular complexes (R-on-T phenomenon) followed by polymorphic ventricular tachycardia (Torsade de Pointes) and ventricular fibrillation 

The patient was promptly defibrillated:

• Successful defibrillation
• Sinus rhythm with complete heart block
• Paced ventricular rhythm, 66/min

Angiography demonstrated presence of severe diffuse coronary artery disease. The patient underwent aorto-coronary bypass surgery.