Cardiac evaluation before non-cardiac surgery

Cardiac evaluation before non-cardiac surgery

Purpose of preoperative evaluation is not to give medical clearance, but an evaluation of patient’s current medical status to make perioperative recommendations on evaluation, management and risk of cardiac problems. It is also necessary to provide a clinical risk profile to the patient, non-physician caregivers, primary physician, anesthesiologist and surgeon for making treatment decisions which will influence short- and long-term cardiac outcomes.

Active cardiac conditions which should be treated before noncardiac surgery

Unstable coronary syndromes which include unstable or severe angina (Class III / IV) and recent myocardial infarction; decompensated heart failure – class IV, worsening or new-onset heart failure; significant arrhythmias which include high-grade AV block, Mobitz II AV block, complete heart block, symptomatic bradycardia, symptomatic ventricular arrhythmias and supraventricular arrhythmias with uncontrolled ventricular rates above 100/ min; severe valvular disease like severe aortic stenosis and symptomatic mitral stenosis require treatment before noncardiac surgery.

Targeted history in assessing cardiac status

Any history of implanted devices like pacemaker or ICD has to be sought. History of orthostatic intolerance, any recent change in symptoms of cardiovascular disease, current medications used, including herbal and nutritional supplements, and dosages; use of alcohol, tobacco and OTC / illicit drugs should be documented.

Physical examination in assessing cardiac status

Measurement of blood pressure in both arms, carotid pulse contour and bruits, JVP and pulsations, precordial palpation and auscultation, auscultation of the lungs, abdominal palpation, examination of extremities for edema and vascular integrity are essential. Anemia may exacerbate myocardial ischemia and aggravate heart failure.

Revised cardiac risk index

Six independent risk correlates high risk correlates include (1) Ischemic heart disease – history of myocardial infarction, history of positive treadmill test, use of nitroglycerin, current complaints of cardiac pain or ECG with abnormal Q waves; (2) Congestive heart failure – history of heart failure, pulmonary edema, paroxysmal nocturnal dyspnoea, peripheral edema, bilateral rales, S3, chest x-ray with pulmonary vascular redistribution; (3) Cerebral vascular disease – history of transient ischemic attacks (TIA) or stroke; (4) High-risk surgery – abdominal aortic aneurysm, other vascular, thoracic, abdominal or orthopedic surgery; (5) Preoperative insulin treatment for diabetes mellitus and (6) preoperative serum creatinine more than 2 mg per dL.

Supplemental preoperative evaluation

Assessment of risk for coronary artery disease and functional capacity can be done with 12-Lead ECG, exercise stress testing and pharmacological stress testing whenever needed. Avoid stress testing in unstable patients and consider coronary angiography in such situations. Assessment of LV Function can be done by echocardiography, radionuclide angiography or contrast ventriculography.

Please note that emergency surgery for life threatening conditions should not be deferred just because of perceived cardiovascular risk.