ADRB2 and Ventricular arrhythmia: Following this line of reasoning, in vitro and in vivo studies using animal models of CIR showed that treatment with β-adrenoceptor (β-AR) agonist isoproterenol (ISO) or ischemic preconditioning (IPC) protocol reduced infarct size, cardiac necrosis and ventricular arrhythmia (VA), reinforcing the concept of sympathetic mechanisms involvement in cardioprotection8-.11