Concealed Ventricular Extrasystoles

Abstract

Evidence is presented for the new concept that ventricular extrasystoles can be "concealed," i.e., that the extrasystolic focus may be discharged without its impulse invading the surrounding myocardium, as in the "exit block" of parasystole. Concealed bigeminy is recognized when only odd numbers of sinus beats intervene between consecutive extrasystoles. Concealed trigeminy is recognizable when a multiple of 3 plus 2, i.e., 5, 8, 11, 14, etc., sinus beats invariably occupy the interectopic intervals. These concealed extrasystolic rhythms are illustrated and discussed. A genetic relationship between ventricular bigeminy and parasystole is reaffirmed.