Preconditioning in humans.

Brief ischemia to the myocardium initiates a cascade of biochemical events in cardiac myocytes that protects the heart muscle during subsequent ischemic insults. This phenomenon is called ischemic preconditioning. If an acute myocardial infarction is preceded by preinfarction angina, it results in smaller infarction size, fewer cardiac arrhythmias, and better-left ventricular function. During coronary intervention, brief balloon inflation protects the heart during subsequent inflations. Patients vary in the degree of preconditioning and those patients who have the ability to demonstrate a significant preconditioning effect will have lesser incidence of subsequent cardiac events. Preconditioning protects the myocardium during coronary artery bypass surgery, particularly in the off-pump procedure, yet the thoracic surgery community has not universally adopted this technique.