Prognostic value of heart rate variability analysis in patients with depressed left ventricular function irrespective of cardiac rhythm

A new index of heart rate variability - HRF Fraction - was developed and its value for risk stratification was evaluated in 480 patients with coronary heart disease. The main purpose to introduce the HRVF was to overcome one of the most important constraints - cardiac arrhythmia, especially atrial fibrillation - that limits use of HRV measurement as a routine clinical tool. In 384 patients with sinus rhythm (SR) and 96 with AF HRV measurements from 24h ambulatory ECG were performed. Patients were followed for a median period of 28 months. The HRV indices in those who died were compared to those who survived. Authors found that HRV Fraction and - among standard time-domain indices - only SDANN, possessed properties that allow HRV measurement to be applied for risk stratification studies in unselected population of patients with cardiac arrhythmia.