THE EFFECTS OF CARVEDILOL ON LEFT VENTRICULAR FUNCTIONS AND ARRHYTHMIAS IN PATIENTS WITH SEVERE CARDIAC FAILURE

Objective: Arrhythmia are seen frequently in patients with heart failure (HF). Carvedilol which has both beta-blocker and alfa-blocker properties has led to new expectations in the treatment of HF. Our aim is to explore the effect of carvedilol on left ventricular (LV) function and development of arrhythmia in patients with HF. Materials and method: Thirty-one patients (60 +/- 10 years, F/M:11/20) were enrolled for the study who had advanced HF in sinus rhythm. After echocardiography, 24 hour Holter, heart rate variability analysis (HRV), signal averaged ECG, carvedilol was added to their treatment (diuretic and ACEI). Carvedilol dosage was increased to the upper tolerable limit. The same analysis were repeated in 12th and 24th week. Results: Marked improvement was found in LV function in 12 and 24th week (respectively; EF % 30.1 +/- 6.3 vs 33.8 +/- 6.8, p:0.005, Tei index: 0.50 +/- 0.21 vs 0.40 +/- 0.15, p:0.006 and EF % 30.1 +/- 6.3 vs 33.7 +/- 6.6, p:0.01, Tei index: 0.50 +/- 0.21 vs 0.41 +/- 0.19, p:0.03). Before carvedilol, arrhythmias including VT were found in eight patients in holter, whereas they were observed in five patients at 12th week. While late potential positivity was found in 10 patients initially and was found in 7 patients at 24th week. Total QRS was decreased significantly (120.6 +/- 28.8 vs 116.3 +/- 24.3, p: 0.03). Significant increases were observed in SDNN both at 12th week and 24th week (respectively 64.2 +/- 30.3, 89.5 +/- 36.2, 93.5 +/- 37, p<0.001) and SDANN (16.1 +/- 8.3, 22.8 +/- 16.5, 20.6 +/- 8.8, p:0.02, p:0.003). Conclusion: Carvedilol causes improvement in LV systolic function, decreases the frequency of arrhythmia, decreases late potential positivity and improves HRV parameters in HF patients.