THE INFLUENCE OF CARDIAC RESYNCHRONIZING THERAPY ON VEGETATIVE HEART RHYTHM REGULATION IN INDIVIDUALS WITH CONGESTIVE HEART FAILURE

Abstract

Aim. To study the influence of cardiac resynchronizing therapy (CRT) on autonomous cardiac regulation during follow-up in patients (pts) with chronic heart failure (CHF). Material and methods. 22 pts (14 (63,6%) males, mean age 50±10,0 years) with implanted cardiac resynchronization devices were examined. 14 (63,6%) pts had ischemic cardiomyopathy, 12 pts (54,6%) were in NYHA class II, 6(27,3%) – III, 4(18,1%) – IV. Mean follow-up was 12,5 [9,3;13,3] months. Heart rate variability (HRV) analysis was performed on 5-minute ECG recordings made at rest and in active orthostatic test (AOT). Echocardiographic and electrocardiographic parameters were estimated. Pts with a decrease in left ventricular end-systolic volume ≥15% was classified as responders (n=11 – gr.I) and <15% – nonresponders (n=11 – gr. II). Results. At baseline in gr.II higher pulmonary artery systolic pressure (PASP) and right ventricle dimension were detected. At baseline in gr.I significant LF/HF increase, SDNN and TP decrease in AOT were observed. During prospective study in gr.I LF/HF increase in AOT was significant and LF and LF% were higher as compared with initial. At baseline and during follow-up in gr.II HRV parameters were unchanged. Conclusion. CRT exerts positive influence on autonomic cardiac regulation in CHF patients. Preservation of sympathetic reactivity in AOT probably can be used as a marker of a good CRT response.