January 23, 1967

Synchronous Electronic Ventricular Pacing in Complete Heart Block

JAMA. 1967;199(4):261-264. doi:10.1001/jama.1967.03120040071013

On June 27, 1962, the first synchronous pacer with myocardial electrodes was implanted in man.1 This type of pacer functions by picking up the atrial signal and, after a delay roughly equivalent to a normal P-R interval, provides a stimulus to the ventricles. The concept of electronic atrioventricular sequential activation was first reported by Folkman and Watkins2 and later by Stephenson et al3-5 and Kahn et al.6 These early investigators successfully produced atrioventricular synchrony for short periods in dogs. Each added changes and refinements to the circuitry permitting closer simulation of the normal parameters of the heart by producing, electronically, a P-R interval and a blocking circuit for the limitation of ventricular rates in supraventricular tachycardia. Endocardial synchronous pacing was first accomplished by Battye and Weale7 using twin electrodes: one serving as the atrial lead, the other for ventricular stimulation. The electronics of such a