Approaches to the prevention of perioperative myocardial ischemia.

Goals for the perioperative management of patients with coronary artery disease include: * Prevent increases in sympathetic nervous system activity: reduce anxiety preoperatively; prevent stress response and release of catecholamines by appropriate use of opioids or volatile anesthetics and beta-adrenoceptor antagonists; beta-blocker therapy should be initiated before and continued during and after the surgical procedure. * Decrease heart rate: reduction in heart rate increases oxygen supply to ischemic myocardium and reduces oxygen demand; the use of beta-blockers is the most effective means to reduce or attenuate deleterious increases in heart rate. * Preserve coronary perfusion pressure: decreases in diastolic arterial pressure in the presence of severe coronary artery stenoses will lead to decreases in blood flow; preservation of perfusion pressure by administration of fluid or phenylephrine or a reduction in anesthetic concentration may be critical. * Decrease myocardial contractility: reduces myocardial oxygen demand and can be accomplished with beta-adrenoceptor antagonists or volatile anesthetics. * Precondition myocardium against stunning and infarction: in the future, this may accomplished by stimulating the adenosine triphosphate- dependent potassium channel with agents such as volatile anesthetics and opioid delta1-receptor agonists.