Termination and suppression of multifocal atrial tachycardia with verapamil.

Multifocal atrial tachycardia (MAT) is an ectopic atrial tachyarrhythmia most commonly observed in very ill, elderly patients with hypoxia due to chronic pulmonary or cardiac disease. We have described a patient with recurrent MAT whose paroxysms of arrhythmia were promptly terminated with intravenous verapamil and were ultimately prevented by orally administered verapamil.