Five-minute recording of heart rate variability in severe chronic heart failure: Correlates with right ventricular function and prognostic implications

ters of disease severity is still unclear. A reduced HRV has been related t o left but not to right ventricular function parameters. Moreover, the prog nostic role of spectral measures is not fully defined. We sought to assess HRV by using a short electrocardiographic recording in ambulatory patients with severe CHF to investigate the relation of HRV with clinical neurohormo nal and hemodynamic parameters and to determine its predictive prognostic p ower. Methods and Results HRV was obtained from 5-minute electrocardiographic rec ordings in 75 ambulatory patients with CHF referred for heart transplantati on screening. Standard frequency-domain parameters (total power, low-freque ncy power, and high-frequency power) were calculated Prognostic value of th ese autonomic markers and their correlation with clinical and instrumental parameters were also assessed. A low low-frequency/high-frequency ratio was an independent predictor of cardiac events (P = .015). No correlation was found between New York Heart Association class and HRV, whereas significant correlations were identified between norepinephrine plasma levels, several hemodynamic parameters, and spectral measures (P less than or equal to .03 ). A reduced HRV, particularly a low-frequency power reduction (P = .000), was highly related to indexes of right ventricular dysfunction. Conclusions The current data indicate that spectral analysis of HRV, calcul ated from short electrocardiographic recordings, may represent a simple but effective means contributing to risk stratification of patients with sever e CHF, Autonomic information obtained from this analysis suggests that righ t ventricular dysfunction may be a critical element determining autonomic i mbalance in patients with severe CHF.