Exercise testing is a cardiovascular stress test that uses treadmill bicycle exercise with electrocardiography (ECG) and blood pressure monitoring.Pharmacologic stress testing, established after exercise testing, is a diagnostic procedure in which cardiovascular stress induced by pharmacologic agents is demonstrated in patients with decreased functional capacity or in patients who cannot exercise. Pharmacologic stress testing is used in combination with imaging modalities such as radionuclide imaging and echocardiography.
Exercise stress testing, which is now widely available at a relatively low cost, is currently used most frequently to estimate prognosis and determine functional capacity, to assess the probability and extent of coronary disease, and to assess the effects of therapy. Ancillary techniques, such as metabolic gas analysis, radionuclide imaging, and echocardiography, can provide further information that may be needed in selected patients, such as those with moderate or prior risk.
Cardiovascular exercise stress testing in conjunction with ECG has been established as one of the focal points in the diagnosis and prognosis of cardiovascular disease, specifically coronary artery disease (CAD).
Treadmill stress testing is indicated for diagnosis and prognosis of cardiovascular disease, specifically CAD. Contraindications have been outlined in guidelines from the American College of Cardiology (ACC) and the American Heart Association (AHA).
Absolute contraindications include the following:
- Acute myocardial infarction (MI; within 2 days)
- Unstable angina not previously stabilized by medical therapy – Appropriate timing of tests depends on the level of risk of unstable angina as defined by the Agency for Health Care Policy and Research Unstable Angina Guidelines
- Uncontrolled cardiac arrhythmias causing symptoms or hemodynamic compromise
- Symptomatic severe aortic stenosis
- Uncontrolled symptomatic heart failure
- Acute pulmonary embolus or pulmonary infarction
- Acute myocarditis or pericarditis
- Acute aortic dissection
Relative contraindications can be superseded if the benefits of exercise outweigh the risks. They include the following:
- Left main coronary stenosis
- Moderate stenotic valvular heart disease
- Electrolyte abnormalities
- Severe arterial hypertension – In the absence of definite evidence, the committee suggests an SBP higher than 200 mm Hg, a DBP higher than 110 mm Hg, or both
- Tachyarrhythmias or bradyarrhythmias
- Hypertrophic cardiomyopathy and any other forms of outflow tract obstruction
- Mental or physical impairment leading to an inability to exercise adequately
- High-degree atrioventricular (AV) block
When the diagnosis of CAD is confirmed on the basis of age, sex, description of chest pain, and history of previous MI, a clinical need may arise for risk or prognostic assessment to reach a decision regarding possible coronary angiography or revascularization to guide further medical management. (IW 2724)
Ref: Libby P, Bonow RO, Mann DL, Zipes DP. Exercise stress testing. In: Braunwald E, ed. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Philadelphia, Pa: WB Saunders; 2007.
Botvinick EH. Current methods of pharmacologic stress testing and the potential advantages of new agents. J Nucl Med Technol. Mar 2009;37(1):14-25.