Polymorphous ventricular tachycardia following cardiopulmonary bypass.

A 62-year-old African-American man who underwent coronary artery bypass surgery was found to have repetitive ventricular tachycardia of the "Torsade des pointes" type. The arrhythmia was resistant to bretylium, lidocaine, and pacing, but was controlled by intravenous magnesium sulfate. The recurrent attacks were abolished by a bolus of 1 g magnesium sulfate and controlled using a 1 mg/minute drip for 12 hours. This case shows the effectiveness of intravenous magnesium in controlling Torsade des pointes in postoperative coronary bypass patients.