Impaired heart rate variability is a risk factor for cardiovascular morbidity and mortality. The aim of our study was to assess the heart rate variability (HRV) of our coronary population and to determine the factors that influence it.

Retrospective study including 72 coronary patients with preserved or slightly altered LEQeft ventricular (LV) systolic function, having benefited from a 24-hour rhythmic Holter for palpitations or for paroxysmal arrhythmias not clearly established, between November 2018 and July 2019. HRV was compared to control subjects. A correlation between HRV and several clinical and biological factors has also been sought.

The mean age was 64.5years. All parameters of HRV were reduced in coronary patients compared to controls with a significant difference (P<0.0005). The mean HRV was 89±34.2ms, it was altered in 23 patients (31.9%) without significant difference between the sexes.

HRV was significantly reduced in the 36 diabetic patients in our series (P<0.01) and in the oldest patients (˃65years) (P=0.02). On the other hand, it seems improved in patients on beta-blockers.

Assessment of autonomic dysfunction by HRV measurement is an easy way to identify coronary patients with preserved or little altered LVEF at high-risk of morbidity and mortality. The negative effect of older age and diabetes, and the positive effect of beta-blockers on HRV found in our study, were also demonstrated in several previous studies.