[Effect of aortic clamping on heart function in elective operation of the abdominal aorta: immediate effects of...

Infrarenal aortic cross-clamping required during surgical treatment of abdominal aortic aneurysm is generally well tolerated but can be occasionally associated with severe cardiac and haemodynamic disturbances, particularly in patients suffering from coronary artery disease. We compared the haemodynamic changes and the ECG-records before and shortly after infrarenal aortic clamping in three groups of 20 patients (group I: without coronary artery disease, group II: with overt coronary disease without indication for prior myocardial revascularization, and group III: patients undergoing combined procedure: coronary artery bypass immediately prior to aortic repair, during the same anesthesia). There was no significant difference in demographical characteristics between the three groups. Aortic cross-clamping lead to an increase in systemic arterial pressure in all patients. Group I demonstrated a decrease in pulmonary artery pressure, pulmonary capillary wedge pressure and central venous pressure, whereas patients of group II demonstrated an increase of each value when the aorta was clamped. 11 patients of this group developed either arrhythmia and/or ischemia during aortic cross-clamping. Haemodynamic and cardiac effects of aortic clamping seen in patients who had received coronary bypass immediately prior to aortic repair (group III) were surprisingly similar to those of patients without coronary disease, probably owing to systematic application of 2 vasodilators. Tolerance to infrarenal aortic cross-clamping differs in patients with and without coronary artery disease. Development of myocardial ischemia may be predicted by an increase in wedge pressure after clamping. Afterload reduction was the best treatment of ischemia occurring when the aorta was clamped.