Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ KEY FEATURES +++ ESSENTIALS OF DIAGNOSIS ++ Objective evidence of myocardial ischemia is the absence of angina pectoris or its equivalent Most patients have underlying coronary artery disease Ambulatory ECG monitoring shows ischemic ST transients during normal activities or a positive stress test documenting ischemia +++ GENERAL CONSIDERATIONS ++ May occur in patients who have never developed symptoms or in patients who had prior symptomatic cardiac events Ambulatory ECG monitoring has increased the recognition of this condition Asymptomatic ST-segment deviation at night suggests 2- or 3-vessel disease Silent ischemia is a significant predictor of mortality Heart rate and blood pressure increase before silent ischemia Altered peripheral pain perception and cerebral cortical dysfunction have been proposed as mechanisms for silent ischemia Diabetics are more prone to silent ischemia Occurs in up to one-quarter of patients with coronary microvascular dysfunction +++ CLINICAL PRESENTATION +++ SYMPTOMS AND SIGNS ++ Sudden death Patients may not experience chest pain even during acute myocardial infarction (MI) +++ PHYSICAL EXAM FINDINGS ++ Generally noncontributory +++ DIFFERENTIAL DIAGNOSIS ++ False-positive ECG or cardiac imaging studies Variant or vasospastic angina with atypical symptoms +++ DIAGNOSTIC EVALUATION +++ LABORATORY TESTS ++ CBC, metabolic panel Lipid panel Troponin I or T Brain natriuretic peptide levels +++ ELECTROCARDIOGRAPHY ++ ECG may show ischemic changes Ambulatory ECG monitoring showing ST transients is diagnostic Exercise stress test may be positive +++ IMAGING STUDIES ++ Stress nuclear perfusion scan may be abnormal +++ DIAGNOSTIC PROCEDURES ++ Coronary angiogram indicated if: – The perfusion scan shows high-risk changes (large area of ischemia or left ventricular dilatation on stress) – There is asymptomatic nocturnal ST depression +++ TREATMENT +++ CARDIOLOGY REFERRAL ++ These patients require evaluation by a cardiologist +++ HOSPITALIZATION CRITERIA ++ After coronary angiogram if percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) is planned +++ MEDICATIONS ++ Beta blockers are the mainstay of therapy because most episodes are associated with increased myocardial oxygen demand Nitrates and calcium channel blockers are less effective Control any underlying atherosclerosis (ie, cholesterol lowering) +++ THERAPEUTIC PROCEDURES ++ PCI in selected patients +++ SURGERY ++ CABG in selected patients +++ MONITORING ++ ECG monitoring in hospital +++ DIET AND ACTIVITY ++ Cardiac low-fat diet Aerobic exercise as tolerated +++ ONGOING MANAGEMENT +++ HOSPITAL DISCHARGE CRITERIA +... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free a profile for additional features.