Beta-blockers are a class of drugs that selectively bind to beta-adrenergic receptors, thereby antagonizing the agonistic effects of neurotransmitters and catecholamines on beta-receptors. The main mechanism is to counteract the toxicity of catecholamine-type adrenergic transmitters, especially through β1 receptor-mediated cardiotoxicity, and other mechanisms include anti-hypertension, anti-myocardial ischemia, and some blockade of the renin-angiotensin-aldosterone system by inhibiting renin release. In addition, they include improvement of cardiac function, increase in left ventricular ejection fraction, and anti-arrhythmias.