Autocorrelation of Ventricular Response in Atrial Fibrillation

Abstract

The autocorrelation function of the ventricular electrocardiogram was calculated on an IBM-650 computer. The resulting function can lie fitted by an exponential-cosine function. This result is typical for a mixture of periodic and unperiodic events. For different patients, various degrees of periodicity were put in evidence by this method on a quantitative basis; the ventricular response was never completely irregular. In all cases investigated so far, the period that corresponds to the periodic component of the autocorrelation function was more rapid than the average rate of ventricular conduction.

Clustering of RR Intervals Predicts Effective Electrical Cardioversion for Atrial Fibrillation

“…Of the total group of 66 patients with AF, the 3D plots indicated the presence of clustering in 31 patients (47%), leaving 35 patients in whom no clustering was demonstrable. As such, our study supports the work by previous investigators 7–10 that a certain degree of “hidden” clustering of RR intervals may be present in AF. Moreover, based on our data, it appears that clustering is not a rare phenomenon.…”

“…However, controversy exists whether the ventricular rhythm in AF is truly random. Although some investigators contend that ventricular rhythm in AF is indeed truly random, 6 others, using a variety of mathematical techniques, have shown that a certain degree of “patterning” (or “clustering”) may be present 7–10 . This in turn suggests a certain degree of organization of atrial fibrillatory activity.…”

Artificial Atrial Fibrillation in the Dog

“…These controversies arise from the fact that different groups of investigators have found differing patterns of ventricular irregularity in patients with atrial fibrillation (2)(3)(4)(5)(6) . Our findings (6) indicate that the ventricular rhythm is random, while others have produced evidence for a measurable amount of interdependence between successive R-R intervals ( time between R waves of two successive QRS complexes).…”

Frequency-dependent effects of diltiazem on the atrioventricular node during experimental atrial fibrillation.

“…Progressive amplification by increases in atrial rate led to maximal effects during atrial fibrillation. Although several models have been proposed to account for the ventricular response to atrial fibrillation, [16][17][18][19][20]22,[30][31][32][33][34][35][36][37][38][39][40] our results can be understood by the classic mechanisms proposed by Langendorf16 and extended by others. [17][18][19][20]22,36 It is assumed that rapid, irregular atrial impulses penetrate the AV node with variable strength from multiple directions.…”