Non digitalis induced paroxysmal atrial tachycardia with block I. Management with cardioversion

Experiences with direct current countershock in the treatment of 7 elderly patients with paroxysmal atrial tachycardia with block have been described. The procedure terminated the arrhythmia promptly and safely in 5 patients who had never received digitalis. Sinus rhythm was maintained for up to 27 months. Sinus rhythm was also restored by cardioversion in 1 of 2 patients who had received digitalis previously; the other developed a nodal rhythm. Administration of countershock was followed by the appearance of disturbances of rhythm or conduction in 4 patients who had not received digitalis. This is consistent with the observations of others that the severity of the underlying heart disease and the administered shock play a role in the development of these disturbances.