Ventricular response in atrial fibrillation. A model based on retarded excitation.

Abstract

The data on durations of the intervals between successive R-R waves in the ECG from patients during atrial fibrillation, reported by Horan and Kistler (Circulation Research 9: 305, 1961) show that the larger the mean and modal value in a record the larger were the shortest and longest durations. The finding that the latter extreme was usually a few times larger than the former has been used in an attempt to organize the data with the help of a probabilistic model. It is assumed that a sequence of intervals is generated, the durations of which are symmetrically distributed, but in fibrillation the process is distorted from time to time and larger intervals occasionally occur. The effects of atrial impulses on conduction through the A-V node are discussed. A mathematical expression describing this phenomenon is derived.