[The assessment of factors influencing occurrence of adequate interventions of cardiac resynchronization therapy with cardioverter-defibrillator implanted in primary prevention of sudden cardiac death in dilative cardiomyopathy and percentage of biventricular pacing].

Abstract

The assessment of factors influencing occurrence of adequate interventions of cardiac resynchronization therapy with cardioverter-defibrillator implanted in primary prevention of sudden cardiac death in dilative cardiomyopathy and percentage of biventricular pacing.

Introduction: The function of cardiac resynchronization therapy with cardioverter-defibrillator (CRT-D) is to treat heart failure (HF) and to treat ventricular arrhythmia, if it occurs, with adequate intervention.

Aim: The aim of the study was to find predictors of adequate interventions and in how many patients biventricular pacing percentage decreases during the follow-up.

Material and methods: The study comprised of 228 patients (178 M, mean age 66±10, 31-89 years) with implanted CRTD. The following data were analyzed: age, sex, presence of dilative cardiomyopathy, diabetes mellitus, lowered creatinine clearance, atrial fibrillation (AF), LVEF, NYHA class, adequate interventions, number of arrhythmias, pharmacotherapy modifications, device parameters and mortality.

Results: Mean ejection fraction of the left ventricle was 20.9±6.4, (10.0- 35%). During the mean follow up of 770±490 days in 84 (37%) patients adequate interventions of the device occurred. The adequate interventions concerned mainly patients with diabetes mellitus (HR 2.95), in NYHA class II, with paroxysmal atrial fibrillation (HR 2.15). In 39 patients (17%) the mean percentage of biventricular pacing was below 90%, and in 18 (8%) below 85%.

Conclusions: Diabetes mellitus, NYHA class II, paroxysmal atrial fibrillation have significantly increased the risk of adequate intervention. The most common causes of loss of biventricular pacing were: inappropriate AV delay, supraventricular arrhythmias and premature ventricular complexes. A significant correlation between low biventricular pacing percentage and the occurrence of supraventricular arrhythmias and adequate interventions was observed.