Impact of optimal medical therapy on the arrhytmias and heart rate variability detected with 24 hour Holter in a series of patients from a heart failure clinic

Pharmacological treatment of heart failure (HF) patients usually induces improvements in their functional class (FQ. Heart rate variability and Hotter-detected arrhythmias are sudden cardiac death predictors and should be evaluated in the presence of optimal medical treatment. Methods. We conducted a prospective, observational and linear study to evaluate ventricular arrhythmia presence and heart rate variability through 24-hr Holter. A first recording was made upon admission to the HF clinic and the second was obtained when a stable FC was reached or optimal medication doses where attained. Results. We have controls among 47 patients 11.6 +/- 8.1 months after the enrollment Holler. We have 26 (55.3%) men, with an average age of 60.2 +/- 13.9 years. The main ejection fraction (EF) went from 31.9 to 37.4% during follow-up (p = 0.01). At enrollment, 44.7% of our patients were in a FC I, 27.7% in FC H and 27.7%, in FC III. At the end of follow-up, 67.4% were in FC 1, 27.9% in FC 11 and 4.7% in FC III. Time-domain variability did not show significant changes and remained in normal average values. Premature atrial contractions diminished (324.1 +/- 811.1 vs. 316 +/- 809.2) but the ventricular ones went from 1,493.6 +/- 3,530.9 in 24 hours, to 1,582.4 +/- 4,394.5 (p = ns) during control, among those with, an EF < 40% and SDNN < 100 ms, we found an increase from 7,026.6 +/- 12,168.8 to 9,336 +/- 16,137.8 PVCs in 24-hours (p = 0.008). Conclusion. Optimal medical therapy for heart failure can positively change certain aspects of these patients, but it does not improve the arrhythmic sudden death risk profile.