MI, myocardial infarction; AV, atrioventricular; ECG, electrocardiogram; LVH, left ventricular hypertrophy; LBBB, left bundle branch block. Adapted from Fleisher LA, Beckman JA, Brown KA, et al. 2009 ACCF/AHA focused update on perioperative beta blockade incorporated into the ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation 2009;120:e169–e276.
Table 22.16 Functional Capacity Assessment from Clinical History
Carry 24 lb up eight steps Carry objects that weigh 80 lb Outdoor work (shovel snow, spade soil) Recreation (ski, basketball, squash, handball, jog, or walk 5 mph)
Have sexual intercourse without stopping Walk at 4 mph on ground level Outdoor work (garden, rake, weed) Recreation (roller-skate, dance)
Shower and dress without stopping Basic housework Walk 2.5 mph on level ground Recreation (golf, bowl)
Adapted from Mehta RH, Bossone E, Eagle KA. Perioperative cardiac risk assessment for noncardiac surgery. Cardiologia 1999;44:409–418.
prior cardiomyopathy, or with any of the above factors and no cardiac assessment in the past 12 months should consider echocardiogram testing preoperatively (179). Exercise stress testing before surgery can identify patients who have ischemic heart disease not apparent at rest.
AHA guidelines recommend noninvasive stress testing for patients with one to two clinical risk factors, undergoing intermediate risk surgery with poor functional capacity of METS less than 4. Likewise, it is recommended for patients with greater clinical risk factors or those undergoing high-risk surgery (179). These patients are at increased risk of developing cardiac complications in the perioperative period. In a study of patients undergoing peripheral vascular surgery, a high-risk group of patients was identified who had ischemic electrocardiographic changes when they exercised to less than 75% of their maximal predicted heart rate. In this group, the incidence of perioperative myocardial infarction was 25% and the overall cardiac mortality rate was 18.5%. Conversely, no perioperative infarctions occurred in patients who were able to exercise to more than 75% of their maximal predicted heart rate and who had no electrocardiographic evidence of ischemia (181). The prognostic value of stress testing was not supported in another prospective study that found that only an abnormal preoperative resting electrocardiography result was an independent risk factor (182). The exercise stress test must be selectively applied to a high-risk population because its predictive value depends on the prevalence of the disease. It is not prudent to screen all patients preoperatively; it is preferable to rely on a careful history to identify patients with symptoms of cardiac disease for whom the test would be most predictive.