Paroxysmal Atrial Tachycardia with Atrioventricular Block

Abstract
Paroxysmal atrial tachycardia with block is a cardiac arrhythmia that is usually a manifestation of digitalis toxicity in patients with serious heart disease. The arrhythmia generally ends promptly after potassium administration and withdrawal of digitalis. Since the ventricular rates may be slow and regular, the arrhythmia may be difficult to recognize clinically. Atrial rates as slow as 115 per minute may be seen in cases which are otherwise typical of the condition. In our series associated pulmonary disease was present in 54 per cent and cor pulmonale in 27 per cent of the cases.