Abstract 9455: Change of Heart Rate Variability and Correlation With Cardiac Function During Development Process of Chronic Heart Failure in Large Animal Model

Abstract

Introduction; Heart rate variability (HRV) is conceived to have a close relationship with prognosis of heart failure (HF). However, there is few study on HRV during diagnostic and treating process of HF in clinical settings. By investigating this process, HRV may become a more useful approach for non-invasive estimation of cardiac function. In this study, we examined the change of HRV and its correlation with cardiac function throughout the entire course of progressing HF in newly developed large animal chronic heart failure (CHF) models created by combination of micro-embolization and rapid pacing. Methods; CHF was introduced in 12 adult goats (60.9±4.1 kg) by coronary microsphere embolization (50μm, 0.201±0.014 million) to the left anterior descending artery and subsequent rapid ventricular pacing (HR[[Unable to Display Character: ≒]]200) for 5 weeks. Electrocardiogram was recorded continuously for 24 hours under pacing off per week. HRV was analyzed by Memcalc/CHIRAM (Suwa Trust, GMS Inc.), which calculated time-domain index (SDNN etc.) and frequency domain index (LF, HF etc.), evaluated correlation with left ventricle ejection fraction (EF) and cardiac output (CO). Results; Ten goats survived and developed CHF successfully, showing decreased EF (from 90.4±4.1% to 48.3±5.6%) and CO (from 5.6±0.5L/min to 4.0±0.6 L/min). All indexes of HRV were decreased along with progress of HF (SDNN decreased from 166.1±39.1msec to 51.9±33.3msec). LF/HF which is the index of sympathetic nerve activity increased from 1.4±0.9 to 10.7±8.3. A strong correlation was observed between SDNN and cardiac function (Fig). Two cases of sudden death in course showed significant decrease of HRV as compared with the surviving cases. Conclusions; HRV was decreased along with progress of HF, strongly indicating aggravation of sympathetic nerve activity. These findings suggest that HRV analysis has a potential to become a useful and reliable approach for non-invasive estimation of cardiac function and severity of HF.