[Incidence and prevention of coronary complications after general surgery].

The frequency, the nature and physiopathological mechanisms of cardiac complications of general surgical patients are well known. Acute myocardial infarction, the main complication, occurs in 3 to 5% of high risk cases. Though usually subendocardial and asymptomatic, it jeopardizes short and medium term survival of patients. It occurs in the first 48 hours after surgery in the majority of cases, the diagnosis being confirmed by increased serum troponine I levels. The circulatory, mechanical and inflammatory changes and hypercoagulability, which are present during the perioperative period, interact, disturbing the energetic equilibrium of the myocardium and causing episodes of myocardial ischaemia which, if prolonged, result in necrosis of the subendocardial myocardium. These effects must be taken into consideration if the operative risk of coronary patients is to be reduced. It is essential to monitor the haemodynamic parameters which affect myocardial energy consumption both during and after surgery. Particular attention must be paid in the postoperative period which is characterised by metabolic stress and sympathetic hyperreactivity which predispose to prolonged episodes of silent myocardial ischaemia. Betablockers, which effectively prevent per and postoperative ischaemia without causing jeopardy to the haemodynamic status and which reduce the cardiac risk of general surgery have a role to play in the prevention of acute myocardial infarction in the postoperative period when prescribed before surgery and continued by oral administration during the first 6 postoperative days. The alpha-2-agonists affect sympathetic reactivity during and after surgery and are very well tolerated haemodynamically. If the current on-going multicenter trials show that they prevent postoperative cardiovascular complications, they could be prescribed prophylactically in patients at risk.