Modified from Washington RL, Bricker JT, Alpert BS, et al Guidelines for exercise testing in the pediatric age group From the Committee on Atherosclerosis and Hypertension in Children, Council on Cardiovascular Disease in the Young, the American Heart Association Circulation 1994;90:2166–2179 Relative contraindications require that the physician supervising the laboratory evaluate the relative risk and benefit for exercise testing for that particular patient.29,32 A relatively high risk during exercise testing may be acceptable Indeed, many of these relative contraindications can alternatively serve as indications for exercise testing, such as defining functional status in patients with subjectively asymptomatic but otherwise clinically severe aortic stenosis.116,117 Likewise, routine exercise testing in patients with advanced pulmonary vascular obstructive disease is not appropriate because of the high risk of exercise-induced sudden death Exercise testing, nonetheless, may be warranted in that situation as part of an evaluation to make a difficult decision concerning the timing of lung or heart-lung transplantation Reasons to Terminate an Exercise Test There are at least four reasons to terminate an exercise test: The patient requests termination Diagnostic criteria for performing the exercise test have been met The monitoring equipment has failed and this could compromise safety Signs or symptoms are present that suggest the patient could be at significant risk if exercise continues Judging the level of fatigue of the patient using a perceived exertion scale, such as the Borg scale, is useful in anticipating when a patient is likely to refuse further exercise Onset of dizziness, erratic respiratory patterns, or chest pain frequently indicates potential abnormalities requiring termination of testing A significant fall in systolic blood pressure may indicate inadequate cardiac output Likewise, an excessive rise in blood pressure greater than 250 mm Hg may be considered a reason to terminate a test, although there is no evidence of significantly increased risk related to such elevated blood pressure in asymptomatic children who have a structurally normal heart.32 ST segment depression of greater than 3 mm should be observed to indicate significant ventricular ischemia and may be an indication for termination Significant ST elevation is also indicative of important ischemia Increasing frequency of arrhythmias, or exercise-induced high-grade atrioventricular block, will often require termination but should be judged on an individual basis Reasons for potential termination are summarized in Box 23.5, but real-time clinician judgment is an integral part of distinguishing when a given abnormality truly poses risk Careful preparation and monitoring are essential to successful testing If adequate attention is given to appropriate preparation and monitoring, it is unusual that an exercise test will need to be terminated before achieving the diagnostic goals Box 23.5 Indications to Terminate an Exercise Test Patient requests termination Diagnostic criteria for the test are met Equipment failure Chest paina Suggestion of inadequate perfusion of the central nervous system (e.g., dizziness, headache, syncope)a A drop in systolic blood pressure >10 mm Hg Severe dyspneaa Advanced arrhythmias or progressive atrioventricular block ST segment depression >3 mm 10 ST elevation >1 mm in leads without Q waves, other than V1 or aVR 11 Systolic blood pressure >250 mm Hg 12 Progressive drop in systolic blood pressurea aSymptoms should be evaluated with all other monitored patient information to determine if the test needs to be terminated Modified from Washington RL, Bricker JT, Alpert BS, et al Guidelines for exercise testing in the pediatric age group From the Committee on Atherosclerosis and Hypertension in Children, Council on Cardiovascular Disease in the Young, the American Heart Association Circulation 1994;90:2166–2179 ... Modified from Washington RL, Bricker JT, Alpert BS, et al Guidelines for exercise testing in the pediatric age group From the Committee on Atherosclerosis and Hypertension in Children, Council on Cardiovascular