PREOPERATIVE ASSESSMENT OF THE CORONARY C IRCULATION

It is not easy to define a plan for the preoperative assessment of the coronary circulation: some studies carried out in the context of vasc ular surgery are contradictory and no method has a sensitivity and spe cificity of 100 %. Nevertheless, it is essential to select patients wi th a high risk of perioperative cardiac complications so that their me dical treatment can be reinforced or anatomical correction envisaged. A first assessment is obtained from the history, the clinical examinat ion and simple investigations (resting ECG, chest X-ray). Surgical ope rations which do not impose a major strain on the cardiovascular syste m do not require further investigations. The risk of postoperative car diac complications is low in the absence of the nine risk factors defi ned by Goldman and/or an ischemic syndrome (residual angina after mild physical activity, unstable angina, myocardial infarct). The problem arises in patients with the Goldman risk factors and/or a history of c oronary insufficiency and/or coronary insufficiency risk factors (diab etes, tobacco, hypercholesterolemia, age > 70 years, arterial hyperten sion), who require an operation likely to cause a particularly serious strain on the cardiovascular system. An exercise ECG, by the Holter m ethod, is helpful, particularly in known or potential coronary arterio paths who cannot exercise. Echocardiography under dobutamine has good sensitivity and good specificity when exercise is impossible. Thallium -dipyridamole scanning has not been shown to be helpful in vascular su rgery. This method could be refined by a quantitative analysis of the number of areas and segments involved. Finally, patients showing ischa emic changes on continuous ECG recording, abnormalities on echocardiog raphy under dobutamine, abnormalities on thallium-dipyridamole myocard ial scanning or on exercise ECG, should be considered for coronary ang iography with a view to a preliminary anatomical correction.