Class I antiarrhythmic drug and coronary vasospasm-induced T wave alternans and ventricular tachyarrhythmia in a patient with Brugada syndrome and vasospastic angina

A 50-year-old man presented with a history of transient chest pain and palpitations. The 12-lead ECG at rest showed normal sinus rhythm. A slight ST segment elevation was observed in leads V-1 to V-3. During hospitalization, atrial fibrillation developed, and oral pilsicainide was administered. Thirty minutes after the drug was given, the ECG showed marked ST segment elevation in leads V-1 to V-3, and T wave alternans became visible in leads V-2 and V-3. Self-terminating ventricular tachycardia was initiated following frequent ventricular premature complexes, which showed a left bundle branch block pattern. The coronary angiogram was normal, but in the provocation test of vasospastic angina, acetylcholine administration into the left coronary artery resulted in complete occlusion of the left anterior descending and circumflex arteries. Marked ST segment elevation developed in leads I, aVL, and V-3 to V-6 concomitant with visible QT/T alternans in leads V-4 and V., and ventricular tachyarrhythmia was initiated. Brugada syndrome and vasospastic angina coexisted in this patient, and T wave alternans can be used as a predictor of ventricalar tachyarrhythmias in such patients.