Interruption of T waves by premature QRS complexes and the relationship of this phenomenon to ventricular fibrillation

Abstract

The mechanism of interruption of the T wave has been described. It has been shown that interruption may be produced if an area of repolarized myocardium is stimulated before other areas have recovered from the passage of the preceding impulse. However, the extent of interruption of the T wave may be increased by propagation of the premature impulse before local repolarization has been completed. Interruption of the T wave was produced under the following conditions: (1) by the premature stimulation of the ventricular septum after the passage of a supraventricular impulse; (2) by the premature stimulation of the site of origin of an ectopic ventricular complex; and (3) by the premature stimulation of an ischemic area of ventricular myocardium after the passage of a supraventricular complex. Ventricular fibrillation was frequently observed to be precipitated by interruption of the T wave, and evidence has been produced which suggests that such very premature impulses may meet refractory tissue which is bypassed. Re-entry into such bypassed areas might well explain the onset of ventricular fibrillation. I think that these experimental results have provided a physiologic basis for the R-on-T phenomenon as encountered clinically and have confirmed the relationship of T-wave interruption to serious ventricular arrhythmias.