Russian Heart Failure Journal 2006year Relationship between different parameters of heart rhythm variability and the mechanism of death in patients with heart failure and left ventricular systolic dysfunction
Relationship between different parameters of heart rhythm variability and the mechanism of death in patients with heart failure and left ventricular systolic dysfunction
Arbolishvili G.N., Mareev V.Yu., Orlova Ya.A., Belenkov Yu.N.
Urgency. Prediction and mechanism of death in patients with CHF is a most important clinical objective. At the same time, studies have shown that analysis of heart rhythm variability (HRV) permits evaluation of the risk for unfavorable outcome in patients with CHF. Aim. To determine the role of HRV in relation to traditional RF (impaired pumping ability; ventricular arrhythmias) for prediction in patients with CHF; and systolic dysfunction in the era of commonly used β–blockers. Material and methods. Study included 135 patients with II–IV FC CHF which had developed against a background of LV systolic dysfunction, with sinus rhythm. Mean age of patients was 52.4±11.9 years; 56 (42%) patients had II FC, 55 (40%) patients had III FC, and 24 (18%) patients had IV FC; mean LV EF was 30.1±6.7%. Ninety–one patients (68%) had ischemic and 43 (32%) patients had non–ischemic myocardiopathy. All patients underwent Holter ECG monitoring with HRV analysis in both temporal and spectral regions. At the time of enrollment 89% of patients were receiving ACEI and 78% of patients were taking β–blockers. Results. Over the follow–up period (mean 28.8±21 months) 63 patients died. Of them 21 (33%) patients died suddenly; 36 (57%) patients died of progressive decompensation, and 3 (5%) patients died of fatal MI. Stepwise regression analysis was used for treatment of the data. A multivariate model included III–IV NYHA FC and a mean value of all RR intervals <705 msec for 24 hours (HR ≥85 bpm) (RR=1.5; 95 % CI 1.1–3.8; p=0.02) as independent predictors. In a combination of the independent predictors, the relative risk of death resulting from CHF progression increased 14.5 times (RR 14.5; 95% CI 7.5–24.6; p=0.0001). In the multivariate model, independent predictors of sudden death were II FC, LV EF ≤26% and a reduced low frequency to high frequency spectrum ratio (LF/HF) ≤1.5 (RR=1.5; 95% CI 1.2–2.9). When the three above–mentioned independent predictors of high risk for sudden death were combined, the relative risk was 9.5 times increased (RR 9.5; 95% CI 4.4–14.4; р<0.0001). Neither runs of ventricular tachycardia nor frequent ventricular ectopic activity were independent predictors of a high risk for sudden death.