[Beta-adrenergic blockers in congestive heart failure: pro et contra?]

In every patient with congestive heart failure there is a secondary neurohumoral response including increase in serum noradrenaline, renin, angiotensin, aldosteron and antidiuretic hormone or arginine-vasopressin values. Plasma and urine noradrenaline levels are increased proportionally to the severity of ventricular dysfunction, but its reserve is often reduced in the myocardium as well as the density of beta receptors and sensitivity to catecholamines and inotropic responses to the stimulation of adrenergic nerves. Down-regulation of beta-adrenoceptors in the myocardium, verified by the technique of radioligands, with the reduced number of beta-adrenoceptors, is accompanied by the appearance of refractoriness and desensitization to endogenous and exogenous catecholamines. Chronic beta-blockade may improve haemodynamic and clinical function in patients with dilated cardiomyopathy or congestive heart failure, because beta-blockers have potentially beneficial actions: protection of the myocardium from damage by chronic excessive catecholamine stimulation, restoration toward normal of the down-regulated membrane beta-receptor density often seen in heart failure, reduction in the risk of potentially lethal ventricular arrhythmias and beneficial effects on substrate utilization. Our results of investigation in 20 patients with congestive heart failure treated with beta-blockers short and long-term (average 22 months) gave substantial increases in ejection cardiac index and improved functional class and also improved working capacity.