Retrograde conduction from premature ventricular contractions, a common occurrence in the human heart.

On the basis of studies of esophageal electrocardiograms the authors conclude that retrograde conduction to the atria from premature ventricular beats is common and that the theory of normal unidirectional block in the A-V node is not tenable. In most of the cases with retrograde conduction, the latter is not discernible in simultaneously recorded lead II, which explains why the phenomenon has previously been considered rare. Observations on the ventriculoatrial conduction time and the compensatory pause are presented. In two of the cases there are two orders of magnitude of ventriculoatrial conduction time, which, the authors postulate, may be due to two separate pathways of retrograde conduction. R RETROGRADE conduction to the atria from premature ventricular contractions is generally believed to be rare although Ash-man and Hu1l2 state that they have observed this phenomenon repeatedly. We studied the esophageal leads of 33 individuals with premature ventricular beats and believe there is evidence of retrograde conduction in 15. These include cases in which there was no evidence of heart disease as well as cases of heart disease and cases in which the premature beats may have been related to the use of digitalis. The esophageal leads were recorded simultaneously with lead II in 12 of the 15 cases and in most of these the retrograde conduction, apparent in the esophageal leads, is difficult or impossible to recognize in lead II. Little attempt has been made to use this technic in the past. Brown' showed that retrograde P waves could be discerned in esophageal leads. Kline, Conn and Rosenbaum'5 used esophageal leads to demonstrate ventriculoatrial conduction in a case of complete atrioventricular block; at one time they could demonstrate the retrograde conduc-Sponsored by the Veterans Administration and published with the approval of the Chief Medical Director. The statements and conclusions published by the authors are a result of their own study and do not necessarily reflect the opinion or policy of the Veterans Administration. 738 tion in the esophageal leads but not in the simultaneously recorded standard leads. Technic For esophageal exploring electrodes a modified Nyboer tube* was used consisting of rings of Monel metal about 5 mm. in diameter and 3 to 5 mm. long mounted on a soft rubber tube. The optimum position of the esophageal exploring electrode was determined in each case by trial, or several esophageal leads were recorded. The positions of the exploring electrodes in centimeters from …