Session P79.1

Atrio-Ventricular Junction Behavior during Atrial Fibrillation

P Bonizzi*, O Meste, V Zarzoso

Université de Nice
Sophia Antipolis, France

Atrial Fibrillation (AF) is the most common sustained arrhythmia in adults. Epidemiologic studies have shown that its prevalence and incidence doubles with each advancing decade beyond 50 years reaching 10% in people over 80. Although the mechanism and effective treatments for most other supraventricular tachyarrhythmia have been discovered, the understanding of AF remains incomplete. In particular, no unifying mechanism has yet been found to explain the behaviour of the atrio-ventricular junction (AVJ) during AF. It is well known that heart rate variability is enhanced during AF, while other studies have revealed a more complex relationship between AVJ behavior and AF. To shed some light on the AVJ behavior during AF episodes, this study will analyse a possible relationship between the occurrence of a heart beat and the features of the atrial activity (AA) preceding this heart beat in an electrocardiogram (ECG) signal. Features such as the AA power, mean value, maximum value etc. are measured in the interval of the ECG between the onset of the heart beat under analysis and the ending of the previous heart beat (T-Q). After appropriate pre-processing (amongst others: removing baseline wander and normalization) a negative trend was discovered between values of AA power and the cardiac cycle length (RR interval on the ECG). This relation shows a possible coherence between power arriving at the AVJ and the triggering of the heart beat, which is in line with the assumptions made in the Cohen model. Future aspects in this work will include Blind Source Separation techniques to reveal the AA, previously masked by the QRS complex. This AA estimation will subsequently be used to strengthen the hypothesis of the negative trend further supporting the Cohen model.

(Abstract Control Number: 64)