Risk of anesthesia in patients with heart disease
Patients with moderate to severe valvular dysfunction represent a challenge to anesthesiologists because of their specific cardiac pathology. Certain cardiac lesions increase the risk of operation even though cardiac reserve seems good. Patients with severe aortic stenosis or incompetence are particularly susceptible to the development of ventricular fibrillation. Patients with mitral stenosis who have few symptoms can tolerate general surgical procedures reasonably well, but care should be taken not to increase the left atrial pressure and consequent pulmonary edema.1
Management of these patients requires understanding of the altered cardiovascular state, hemodynamic impairment caused by the anatomic lesions, and their altered response to the support of cardiac function. Hemodynamic requirements of different lesions dictate the appropriate choice of anesthetic drugs and techniques. Careful titration of agents to preserve circulatory stability is essential while the patient is undergoing surgery. Selection of anesthetic agents for the patient with certain types of cardiac lesions is also important, such as enflurane and halothane, which are associated with junctional rhythm. Gallamine and ketamine may increase the heart rate; therefore, those agents may not be the optimum choice for tight mitral stenosis. However, narcotics would not depress contractility and change the rhythm, and therefore would be more suitable. The number of patients who have valve disease and undergo operation has declined in the past decade because of the progress made in replacing diseased valves with prosthetic valves. However, replacement of an old, damaged valve with a prosthesis does not guarantee perfect myocardial function. A degree of cardiac . . .