PREOPERATIVE ASSESSMENT OF THE PATIENT WITH CARDIOVASCULAR DISEASE

The morbidity and mortality of anaesthesia and surgery are increased by cardiac diseases. It is essential, therefore, to recognize the presence of cardiovascular diseases and to assess their severity in order to prevent serious complication during anaesthesia and the period after operation. Relatively silent cardiac or vascular diseases are often first diagnosed during the preoperative visit (Kyei-Mensah and Thornton, 1974; Frost, 1976). Where the diagnosis has already been made it is important to evaluate the severity of heart disease, to determine whether or not medical treatment could further improve cardiac function (Howat, 1971; Friedlander, 1973) and to consider the pathophysiology of the disease. The optimal anaesthetic management and the decision on in-vasive monitoring rest on the correct diagnosis of the disease and of its repercussions on the circu-lation. Detailed medical history and careful clini-cal examination, supplemented by electrocardio-gram and chest x-ray, form the basis of evaluation before operation and may have to be comple-mented by echocardiography, cardiac catheteriza-tion and angiography. ISCHAEMIC HEART DISEASE Coronary heart disease causes more than 160000 deaths each year in the United Kingdom. The frequency of coronary artery disease is very high and the disease may not be clinically apparent unless several vessels are obstructed. Cardiac function may be impaired in almost asymptomatic patients. Presence of coronary heart disease causes a two- to three-fold increase of perioperative mortality and a 10-fold increase in coronary occlu-sion after surgery. The risk of postoperative infarction is particularly high when surgery takes place within a few months of a previous infarction. Improvements in anaesthetic management have reduced the frequency of reinfarction from almos