Drugs have long been the mainstay in the treatment of ectopic arrhythmias. The modern pharmacologic era was ushered in by the work of Wenckebach and Fry about 40 years ago. Many agents are now in use for terminating rapid heart action including quinidine, procaineamide, digitalis glycosides, potassium and magnesium salts, and the antihistaminic and sedative drugs. This era may now be drawing to a close.
In this issue of The Journal, Lown and coworkers (p. 548) describe a new method which no longer depends on drugs. By delivering a brief electrical discharge of 3,000 to 7,000 volts across the intact chest, they have been able to terminate a number of arrhythmias, including chronic atrial fibrillation and drug refractory ventricular tachycardia. The electrical impulse depolarizes the entire heart, extinguishes the ectopic complex, and permits the sinus node to resume as pacemaker.
Electrical countershock in the form of alternating current (AC) has