Simultaneous improvement of cardiac contractile performance and autonomic nervous regulation by chronic atenolol-added treatment in advanced congestive heart failure - A combined echocardiography and heart rate variability study

Direct neurohormonal suppression by β-blockers in congestive heart failure always carries the worry of further autonomic nervous perturbation despite the clinical success. To elucidate the dilemma, 15 patients of advanced congestive heart failure (idiopathic in 11, ischemic in 4) were prospectively studied of the temporal evolution of the subjective and objective cardiac function, versus the 24-hour heart rate variability representing autonomic nervous regulation, before and after 1, 3, 6-9 months of additional low-dose atenolol (6.25-25 mg daily) therapy. Two patients deceased prematurely due to unexpected cardiac events within the first month. All 13 survived patients had the clinical improvement of New York Heart Association functional class and objective echocardiographic cardiac contractile performance including the decrease of left ventricular dimensions and the increase of fraction shortening and ejection fraction after at least 3 months of atenolol therapy. The retarded therapeutic course was accompanied by the parallel upheaving of the total, very low, low and high frequency components and the time domain counterparts of the 24-hour heart rate variability, implicating the recovery of the parasympathetic modulation and the baroreceptor function. In conclusion, chronic β-blocker therapy in advanced congestive heart failure improved the global cardiac function and the heart rate variability favoring better sympathovagal balance in a parallel pace.