Absolute indications
Central nervous system symptoms (e.g., ataxia, dizziness, near syncope)
Decrease in systolic blood pressure greater than 10 mm Hg despite an increase in workload and accompanied by other evidence of ischemia
Moderate to severe angina
Signs of poor perfusion (e.g., cyanosis, pallor) ST-segment elevation (> 1.0 mm) in leads without preexisting Q waves because of prior myocardial infarction (other than aVR, aVL, and V1)
Sustained ventricular tachycardia or other arrhythmia (including second- or third-degree atrioventricular block) that interferes with normal maintenance of cardiac output during exercise
Technical difficulties in monitoring electrocardiography or systolic blood pressure
The patient asks to stop
Relative indications
Arrhythmias other than sustained ventricular tachycardia, including multifocal ectopy, ventricular triplets, supraventricular tachycardia, and bradyarrhythmias that have the potential to become more complex or to interfere with hemodynamic stability
Bundle branch block that cannot immediately be distinguished from ventricular tachycardia
Claudication, fatigue, leg cramps, shortness of breath, or wheezing
Decrease in systolic blood pressure greater than 10 mm Hg (persistently below baseline) despite an increase in workload and without other evidence of ischemia
Exaggerated hypertensive response (systolic blood pressure > 250 mm Hg or diastolic blood pressure > 115 mm Hg)
Heart rate > 85% of age-predicted maximum
Increasing chest pain
Marked ST-segment displacement (horizontal or downsloping> 2 mm, measured 60 to 80 milliseconds after the J-point) in a patient with suspected ischemia