Accelerated Junctional Escape

During the routine interpretation of electrocardiograms, 49 cases of spontaneously occurring accelerated, or borderline accelerated, junctional escape complexes (escape intervals of 1200 ± 20 msec) were encountered. Forty-seven of the 49 patients whose cardiograms demonstrated the accelerated junctional escapes had the clinical setting recognized to be associated with the more protracted accelerated junctional rhythm, nonparoxysmal junctional tachycardia. In addition, five patients demonstrated nonparoxysmal junctional tachycardia immediately preceding or subsequent to the cardiograms demonstrating accelerated junctional escape. It is suggested, therefore, that the two arrhythmias, i.e., accelerated junctional escape and nonparoxysmal junctional tachycardia, may be of similar clinical significance.The determinants of the length of the manifest escape interval could be assessed in those cases where two or more junctional escape complexes occurred in sequence, allowing the true interectopic interval to be ascertained. The dominant role of the rate of atrioventricular conduction and the sequence of ventricular and junctional activation in determining the length of the manifest escape interval was apparent.