Prinzmetal's angina with Torsade de Pointes ventricular tachycardia

Two cases of Prinzmetal's angina with Torsade de Pointes Ventricular Tachycardia are described. The patients had severe obstructive coronary disease and developed the arrhythmias while on large doses of conventional antiarrhythmic therapy. Each patient developed multiple episodes of Torsade de Pointes which had to be terminated with defibrillation or right ventricular endocardial pacing. Both patients underwent successful aortocoronary by-pass graft surgery. The possible relationship of prolonged repolarization by the antiarrhythmic therapy and coronary occlusion to the development of Torsade de Pointes is discussed.