Autoregulation limits in organs such as the brain and the kidney may have become reset to higher levels and, thus, these organs will cope poorly with low perfusion pressure. Also, hypertension is associated with cerebrovascular disease and, if carotid artery stenosis is present, this mandates prompt and relatively aggressive support of blood pressure. Ischaemic Heart Disease Spinal anaesthesia is not contraindicated in patients with coronary artery disease. Spinal anaesthesia is capable of substantially modifying the stress response in many types of infra-umbilical surgery. There is no advantage to having the patient awake so that they can report the occurrence of angina.
Silent ischaemia is common, possibly more so if the cardiac sympathetics are blocked.
Appropriate ST-segment ECG monitoring is a more sensitive method of detecting myocardial ischaemia than verbal reports of chest discomfort. Large prospective, properly-randomised studies need to be performed to clarify these issues. The maintainence of adequate circulating fluid volume in these patients is essential. Patients with aortic stenosis have been safely managed with spinal anaesthesia but in this situation the maintainence of arterial pressure is crucial and epidural anaesthesia is often chosen so that the spread of the block can be titrated more gradually. The avoidance of the myocardial depressant effects of many general anaesthetic agents by the use of spinal anaesthesia is an advantage.