[Hemodynamic effect of the clamping of the carotid in the surgically treated coronary patient].

To determine both the incidence of myocardial ischaemia and haemodynamic response to carotid cross-clamping in coronary artery disease, 30 patients undergoing carotid endarterectomy were studied with a clear history of effort related disabling angina pectoris. Myocardial ischaemia was detected by a recording of lead CM5 of the electrocardiogram. A radial arterial and a thermodilution pulmonary catheter were inserted to obtain haemodynamic measurements before and after carotid cross-clamping and unclamping. Anaesthesia was induced with increments of thiopental, fentanyl 6 micrograms X kg-1 and pancuronium. Additional fentanyl (2 micrograms X kg-1) was injected before skin incision and before carotid cross-clamping. Carotid cross-clamping results in a significant increase in both mean arterial blood pressure and capillary wedge pressure. Two patients experienced myocardial ischaemia with ST segment depression during carotid cross-clamping. Nitroglycerin infusion led to the improvement of ST segment depression. When halothane was additionally administered to patients who developed hypertension in response to carotid cross-clamping, arterial blood pressure returned to normal value. These results indicate that carotid cross-clamping increases determinants of myocardial oxygen demand and may cause myocardial ischaemia in patients suffering from angina pectoris.