- Cardiovascular complications account for 25% to 50% of deaths following noncardiac surgery. Perioperative myocardial infarction (MI), pulmonary edema, congestive heart failure, arrhythmias, and thromboembolism are most commonly seen in patients with preexisting cardiovascular disease.
- Regardless of the level of preoperative blood pressure control, many patients with hypertension display an accentuated hypotensive response to induction of anesthesia, followed by an exaggerated hypertensive response to intubation. Hypertensive patients may display an exaggerated response to both endogenous catecholamines (from intubation or surgical stimulation) and exogenously administered sympathetic agonists.
- Patients with extensive (three-vessel or left main) coronary artery disease, a history of MI, or ventricular dysfunction are at greatest risk of cardiac complications.
- Holter monitoring, exercise electrocardiography, myocardial perfusion scans, and echocardiography are important in determining perioperative risk and the need for coronary angiography; however, these tests are indicated only if their outcome would alter patient care.
- Sudden withdrawal of antianginal medication perioperatively—particularly β-blockers—can precipitate a sudden, rebound increase in ischemic episodes.
- The overwhelming priority in managing patients with ischemic heart disease is maintaining a favorable myocardial supply-demand relationship. Autonomic-mediated increases in heart rate and blood pressure should be controlled by deep anesthesia or adrenergic blockade, and excessive reductions in coronary perfusion pressure or arterial oxygen content are to be avoided.
- Intraoperative detection of ischemia depends on recognition of electrocardiographic changes, hemodynamic manifestations, or regional wall motion abnormalities on transesophageal echocardiography. New ST-segment elevations are rare during noncardiac surgery and are indicative of severe ischemia, vasospasm, or infarction.
- The principal hemodynamic goals in managing mitral stenosis are to maintain a sinus rhythm (if present preoperatively) and to avoid tachycardia, large increases in cardiac output, and both hypovolemia and fluid overload by judicious administration of intravenous fluids.
- Anesthetic management of mitral regurgitation should be tailored to the severity of regurgitation and to the underlying left ventricular function. Factors that exacerbate the regurgitation, such as slow heart rates and acute increases in afterload, should be avoided. Excessive volume expansion can also worsen the regurgitation by dilating the left ventricle.
- Maintenance of normal sinus rhythm, heart rate, vascular resistance and intravascular volume is critical in patients with aortic stenosis. Loss of a normally timed atrial systole often leads to rapid deterioration, particularly when associated with tachycardia. Spinal and epidural anesthesia are relatively contraindicated in patients with severe aortic stenosis.
- Bradycardia and increase in systemic vascular resistance (SVR) increase the regurgitant volume in patients with aortic regurgitation, whereas tachycardia can contribute to myocardial ischemia. Excessive myocardial depression should also be avoided. The compensatory increase in cardiac preload should be maintained, but excessive fluid replacement can readily result in pulmonary edema.
- In patients with congenital heart disease, an increase in SVR relative to pulmonary vascular resistance (PVR) favors left-to-right shunting, whereas an increase in PVR relative to SVR favors right-to-left shunting.
- The presence of shunt flow between the right and left hearts, regardless of the direction of blood flow, mandates the meticulous exclusion of air bubbles or particulate material from intravenous fluids to prevent paradoxical embolism ...
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