A 66-year-old woman with a history significant for heavy smoking and chronic alcohol use and dyspnea on mild exertion for the past 3 years is presenting to the Emergency Department with palpitation, faintness and dyspnea of 1 hour duration with no chest pain.

• Ventricular tachycardia

There is a regular wide QRS tachycardia, 174/min. The QRS duration is only moderately prolonged to 120 msec. There may be P waves with AV dissociation in the lead II 10 sec. strip, however,this is questionable. The QRS pattern in the chest leads, with positive concordance (broad R waves in V1 to V6) strongly favours the diagnosis of ventricular tachycardia.

DC cardioversion and drug therapy were at first unsuccessful, however, the patient converted to sinus rhythm after 4 hours and the following ECG was recorded:

• Poor R wave progression from V1 to V3, suggestive of possible septal infarction

There was elevation of the serum troponin, suggestive of a recent infarction. Coronary angiography demonstrated a moderate stenosis in the midsegment of the left anterior descending artery and a total occlusion of the right coronary artery. The left ventricular ejection fraction was 30%, with akinesis of the inferior wall. An ICD (Implantable Cardioverter-Defibrillator) was implanted.