- Cardiovascular complications account for
25–50% of deaths following noncardiac surgery.
Perioperative myocardial infarction (MI), pulmonary edema, congestive
heart failure (CHF), arrhythmias, and thromboembolism are most commonly
seen in patients with preexisting cardiovascular disease.
- The two most important preoperative risk factors
are an unstable coronary syndrome and evidence of CHF. Generally
accepted contraindications to elective noncardiac surgery include
a myocardial infarction less than 1 month prior to surgery with
evidence of persistent ischemic risk by symptoms or noninvasive
testing, uncompensated heart failure, and severe aortic or mitral stenosis.
- 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
- Patients with extensive (three-vessel or left
main) coronary artery disease, a history of MI, or ventricular dysfunction
are at greatest risk for cardiac complications. Perioperative risk
following MI appears to be related to the amount of residual ischemia
remaining (additional myocardium at risk of infarction).
- Holter monitoring, exercise electrocardiography,
myocardial perfusion scans, and echocardiography are important in
determining perioperative risk and the need for coronary angiography. But
these tests are indicated only if their outcome would alter patient
- Sudden withdrawal of antianginal medication perioperatively—particularly β-blockers—can
precipitate a sudden increase in ischemic episodes (rebound).
- 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.
Down-sloping and horizontal ST depression are of greater specificity
for ischemia than up-sloping depression. 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 fluid therapy.
- Anesthetic management should be tailored to
the severity of mitral regurgitation as well as the underlying left
ventricular function. Factors that exacerbate the regurgitation,
such as slow heart rates (long systole) 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,
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 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 ...
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