Beta-bloccanti e sistema cardiovascolare: Attuali acquisizioni e controversie

In this paper we summarize present trends and controversies in the use of beta-blockers in cardiovascular diseases. Beta-blockers are catecolamine competitive inhibitors and act through alpha and beta adrenergic receptors blockade. Different agents have a dose-dependent affinity for different beta adrenergic receptors (beta 1, beta 2, beta 3) which is less with higher doses. The most important therapeutic effects of beta-blockers are on cardiovascular system, where they act as negative chronotropic and inotropic agents, lowering cardiac work and improving oxygen demand/supply ratio. Clinical indications are numerous. For their anti-ischemic activity beta-blockers are used as anti-anginal drugs and in acute and previous myocardial infarction for preventing total and cardiovascular mortality. Combined use of beta-blockers and ACE inhibitors slows down heart failure progression and reduces cardiovascular mortality. Beta-blockers are useful in treating focal atrial tachycardia and supra ventricular paroxysmal tachycardia, by reducing sinus node automaticity and delay atrio-ventricular conduction; they also prevent sudden cardiac death and ventricular tachycardia associated with increased sympathetic activity. There is no indication in treating primary non-complicated hypertension with beta-blockers as first-line drugs. Different metabolic effects of selective and non-selective beta-blockers are actually debated. In conclusion, betablockers have indication in the treatment of many cardiovascular diseases. Further studies are needed for better understanding the differences in cardiac and peripheral beta-blockers effects depending on their selectivity.