Correlations Between Heart Rate Turbulence Indexes and Pre-ectopic Heart Rate in Heart Failure Patients.

Cardiovascular oscillations following spontaneous ventricular premature complexes (VPC) are described by the so-called heart rate turbulence (HRT) onset (TO) and slope (TS). Since HRT is a marker of baroreflex sensitivity, it can be hypothesized to be affected by the basal HR preceding VPC (pre_HR). The aim of this study was to investigate the relationship between HRT parameters and pre_HR in heart failure (HF) patients. We studied 75 24h ECG Holter recording of HF patients (62±9 years) performing a Spearman correlation analysis between TO, TS and pre_HR values. According to risk stratification standards, each post-VPC response was classified in 0-normal type or 1-abnormal category. T0 showed a weak but significant negative correlation vs. pre_HR in 0-category, completely loosing this association in abnormal responses. TS maintained a moderate significant positive correlation vs. pre_HR for all categories. The weak but significant relation between TS and TO reversed from a negative value in 0-type to a positive one in 1-category. The study demonstrated a weak-to-moderate association between pre_HR and HRT indexes in HF. Correlation patterns, related to different post-VPC response type, must be take into account for suggested HRT adjustment algorithms for HR.