REN and myocardial ischemia: Beta-agonists can stimulate beta-receptors on airway smooth muscle to produce bronchodilator effects and are the basis for COPD, while beta-blockers can counteract the toxicity of catecholamine adrenergic transmitters, especially through beta1 receptors mediated cardiotoxicity, as well as anti-hypertension, anti-myocardial ischemia, blocking the renin-angiotensin-aldosterone system by inhibiting renin release, improving cardiac function and increasing left ventricular ejection fraction, antiarrhythmic and other effects, is the standard treatment of many CVD drugs.