Victor F. Froelicher

ACC/AHA 2002 Guideline Update for Exercise Testing: Summary Article: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1997 Exercise Testing Guidelines)

The American College of Cardiology (ACC)/American Heart Association (AHA) Task Force on Practice Guidelines regularly reviews existing guidelines to determine when an update or full revision is needed. This process gives priority to areas where major changes in text, and particularly recommendations, are mentioned on the basis of new understanding or evidence. Minor changes in verbiage and references are discouraged. The ACC/AHA guidelines for exercise testing that were published in 1997 have now been updated. The full-text guidelines incorporating the updated material are available on the Internet (www.acc.org or www.americanheart.org) in both a version that shows the changes in the 1997 guidelines in strike-over (deleted text) and highlighting (new text) and a “clean” version that fully incorporates the changes. This article describes the 10 major areas of change reflected in the update in a format that we hope can be read and understood as a stand-alone document. The table of contents from the full-length guideline (see next page) indicates the location of these changes. Interested readers are referred to the full-length Internet version to completely understand the context of these changes. All new references appear in boldface type; all original references appear in normal type.⇓ View this table: Table of Contents The ACC/AHA classifications, I, II, and III are used to summarize indications as follows: Class I: Conditions for which there is evidence and/or general agreement that a given procedure or treatment is useful and effective. Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment. IIa: Weight of evidence/opinion is in favor of usefulness/efficacy. IIb: Usefulness/efficacy is less well established by evidence/opinion. Class III: Conditions for which there is evidence and/or general agreement that the procedure/treatment is not useful/effective and in some cases may be harmful. In the original …

Statement on exercise. Benefits and recommendations for physical activity programs for all Americans. A statement for health professionals by the Committee on Exercise and Cardiac Rehabilitation of the Council on Clinical Cardiology, American Heart association.

Physical inactivity is recognized as a risk factor for coronary artery disease. Regular aerobic physical activity increases exercise capacity and plays a role in both primary and secondary prevention of cardiovascular disease.1 2 3 4 5 The known benefits of regular aerobic exercise and current recommendations for implementation of exercise programs are described in this revised report.6 Exercise training increases cardiovascular functional capacity and decreases myocardial oxygen demand at any level of physical activity in apparently healthy persons as well as in most subjects with cardiovascular disease. Regular physical activity is required to maintain these training effects. The potential risk of physical activity can be reduced by medical evaluation, risk stratification, supervision, and education.4 Exercise can help control blood lipid abnormalities, diabetes, and obesity. In addition, aerobic exercise adds an independent blood pressure–lowering effect in certain hypertensive groups with a decrease of 8 to 10 mm Hg in both systolic and diastolic blood pressure measurements.7 8 9 10 There is a direct relation between physical inactivity and cardiovascular mortality, and physical inactivity is an independent risk factor for the development of coronary artery disease.11 12 13 14 There is a dose-response relation between the amount of exercise performed from approximately 700 to 2000 kcal of energy expenditure per week and all-cause mortality and cardiovascular disease mortality in middle-aged and elderly populations.14 15 The greatest potential for reduced mortality is in the sedentary who become moderately active.15 Most beneficial effects of physical activity on cardiovascular disease mortality can be attained through moderate-intensity activity (40% to 60% of maximal oxygen uptake, depending on age).14 15 16 The activity can be accrued through formal training programs or leisure-time physical activities. Although most of the supporting data are based on studies in men, more recent findings …

ACC/AHA Guidelines for Exercise Testing: Executive Summary A Report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines (Committee on Exercise Testing)

The American College of Cardiology/American Heart Association Task Force on Practice Guidelines was formed to make recommendations regarding the appropriate use of testing in the diagnosis and treatment of patients with known or suspected cardiovascular disease. Exercise testing is widely available and relatively low in cost. For the purposes of these guidelines, exercise testing is a cardiovascular stress test using treadmill or bicycle exercise and electrocardiographic and blood pressure monitoring. Pharmacological stress testing and imaging modalities (radionuclide imaging, echocardiography) are beyond the scope of these guidelines. These guidelines have been endorsed by the American College of Sports Medicine, the American Society of Echocardiography, and the American Society of Nuclear Cardiology. This executive summary appears in the July 1, 1997, issue of Circulation. The guidelines in their entirety are published in the July 1997 issue of the Journal of the American College of Cardiology. Reprints of both the executive summary and the full text are available from both organizations. Exercise testing is a well-established procedure that has been in widespread clinical use for many decades. It is described in detail in previous publications of the AHA, to which interested readers are referred. Although exercise testing is generally a safe procedure, both myocardial infarction and death have been reported and can be expected to occur at a rate of up to 1 per 2500 tests. Good clinical judgment should therefore be used in deciding which patients should undergo exercise testing. Absolute and relative contraindications to exercise testing are summarized in Table 1⇓. View this table: Table 1. Contraindications to Exercise Testing The vast majority of treadmill exercise testing is performed in adults with symptoms of known or suspected ischemic heart disease. Special groups who are exceptions to this norm are discussed in detail in sections VI and VII. Sections II through IV illustrate the variety …

American College of Cardiology/American Heart Association expert consensus document on electron-beam computed tomography for the diagnosis and prognosis of coronary artery disease

Coronary artery calcification is part of the development of atherosclerosis; it occurs exclusively in atherosclerotic arteries and is absent in the normal vessel wall. Electron-beam computed tomography (EBCT), the focus of this document, is a highly sensitive technique for detecting coronary artery calcium and is being used with increasing frequency for the screening of asymptomatic people to assess those at high risk for developing coronary heart disease (CHD) and cardiac events, as well as for the diagnosis of obstructive coronary artery disease (CAD) in symptomatic patients. The use of EBCT has the greatest potential for further determination of risk, particularly in elderly asymptomatic patients and others at intermediate risk. The calcium score has been advocated by some as a potential surrogate for age in risk-assessment models. EBCT has also been proposed as a useful technique for assessing the progression or regression of coronary artery stenosis in response to treatment of risk factors such as hypercholesterolemia. EBCT uses an electron beam in stationary tungsten targets, which permits very rapid scanning times. Serial transaxial images are obtained in 100 ms with a thickness of 3 to 6 mm for purposes of detecting coronary artery calcium. Thirty to 40 adjacent axial scans are obtained during 1 to 2 breath-holding sequences. Current EBCT software permits quantification of calcium area and density. Histological studies support the association of tissue densities of 130 Hounsfield units (HU) with calcified plaque. However, a plaque vulnerable to fissure or erosion can be present in the absence of calcium. Also, sex differences play a role in the development of coronary calcium, the prevalence of calcium in women being half that of men until age 60 years. EBCT calcium scores have correlated with pathological examination of the atherosclerotic plaque. This American College of Cardiology (ACC)/American Heart Association (AHA) Writing Group reviewed …

Comparison of the Ramp Versus Standard Exercise Protocols

To compare the hemodynamic and gas exchange responses of ramp treadmill and cycle ergometer tests with standard exercise protocols used clinically, 10 patients with chronic heart failure, 10 with coronary artery disease who were asymptomatic during exercise, 11 with coronary artery disease who were limited by angina during exercise and 10 age-matched normal subjects performed maximal exercise using six different exercise protocols. Gas exchange data were collected continuously during each of the following protocols, performed on separate days in randomized order: Bruce, Balke and an individualized ramp treadmill; 25 W/stage, 50 W/stage and an individualized ramp cycle ergometer test. Maximal oxygen uptake was 16% greater on the treadmill protocols combined (21.4 +/- 8 ml/kg per min) versus the cycle ergometer protocols combined (18.1 +/- 7 ml/kg per min) (p less than 0.01), although no differences were observed in maximal heart rate (131 +/- 24 versus 126 +/- 24 beats/min for the treadmill and cycle ergometer protocols, respectively). No major differences were observed in maximal heart rate or maximal oxygen uptake among the various treadmill protocols or among the various cycle ergometer protocols. The ratio of oxygen uptake to work rate, expressed as a slope, was highest for the ramp tests (slope +/- SEE ml/kg per min = 0.80 +/- 2.5 and 0.78 +/- 1.7 for ramp treadmill and ramp cycle ergometer, respectively). The slopes were poorest for the tests with the largest increments in work (0.62 +/- 4.0 and 0.59 +/- 2.8 for the Bruce treadmill and 50 W/stage cycle ergometer, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Does Size Matter? Clinical Applications of Scaling Cardiac Size and Function for Body Size

Extensive evidence is available that cardiovascular structure and function, along with other biological properties that span the range of organism size and speciation, scale with body size. Although appreciation of such factors is commonplace in pediatrics, cardiovascular measurements in the adult population, with similarly wide variation in body size, are rarely corrected for body size. In this review, we describe the critical role of body size measurements in cardiovascular medicine. Using examples, we illustrate the confounding effects of body size. Current cardiovascular scaling practices are reviewed, as are limitations and alternative relationships between body and cardiovascular dimensions. The experimental evidence, theoretical basis, and clinical application of scaling of various functional parameters are presented. Appropriately scaled parameters aid diagnostic and therapeutic decision making in specific disease states such as hypertrophic cardiomyopathy and congestive heart failure. Large-scale studies in clinical populations are needed to define normative relationships for this purpose. Lack of appropriate consideration of body size in the evaluation of cardiovascular structure and function may adversely affect recognition and treatment of cardiovascular disease states in the adult patient.

Heart Rate Recovery: Validation and Methodologic Issues

OBJECTIVES The goal of this study was to validate the prognostic value of the drop in heart rate (HR) after exercise, compare it to other test responses, evaluate its diagnostic value and clarify some of the methodologic issues surrounding its use. BACKGROUND Studies have highlighted the value of a new prognostic feature of the treadmill test-rate of recovery of HR after exercise. These studies have had differing as well as controversial results and did not consider diagnostic test characteristics. METHODS All patients were referred for evaluation of chest pain at two university-affiliated Veterans Affairs Medical Centers who underwent treadmill tests and coronary angiography between 1987 and 1999 as predicted after a mean seven years of follow-up. All-cause mortality was the end point for follow-up, and coronary angiography was the diagnostic gold standard. RESULTS There were 2,193 male patients who had treadmill tests and coronary angiography. Heart rate recovery at 2 min after exercise outperformed other time points in prediction of death; a decrease of <22 beats/min had a hazard ratio of 2.6 (2.4 to 2.8 95% confidence interval). This new measurement was ranked similarly to traditional variables including age and metabolic equivalents but failed to have diagnostic power for discriminating those who had angiographic disease. CONCLUSIONS Heart rate at 1 or 2 min of recovery has been validated as a prognostic measurement and should be recorded as part of all treadmill tests. This new measurement does not replace, but is supplemental to, established scores.

Electrocardiographic interpretation in athletes: the ‘Seattle Criteria’

Sudden cardiac death (SCD) is the leading cause of death in athletes during sport. Whether obtained for screening or diagnostic purposes, an ECG increases the ability to detect underlying cardiovascular conditions that may increase the risk for SCD. In most countries, there is a shortage of physician expertise in the interpretation of an athletes ECG. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from abnormal findings suggestive of pathology. On 13–14 February 2012, an international group of experts in sports cardiology and sports medicine convened in Seattle, Washington, to define contemporary standards for ECG interpretation in athletes. The objective of the meeting was to develop a comprehensive training resource to help physicians distinguish normal ECG alterations in athletes from abnormal ECG findings that require additional evaluation for conditions associated with SCD.

Cost-Effectiveness of Preparticipation Screening for Prevention of Sudden Cardiac Death in Young Athletes

BACKGROUND Inclusion of 12-lead electrocardiography (ECG) in preparticipation screening of young athletes is controversial because of concerns about cost-effectiveness. OBJECTIVE To evaluate the cost-effectiveness of ECG plus cardiovascular-focused history and physical examination compared with cardiovascular-focused history and physical examination alone for preparticipation screening. DESIGN Decision-analysis, cost-effectiveness model. DATA SOURCES Published epidemiologic and preparticipation screening data, vital statistics, and other publicly available data. TARGET POPULATION Competitive athletes in high school and college aged 14 to 22 years. TIME HORIZON Lifetime. PERSPECTIVE Societal. INTERVENTION Nonparticipation in competitive athletic activity and disease-specific treatment for identified athletes with heart disease. OUTCOME MEASURE Incremental health care cost per life-year gained. RESULTS OF BASE-CASE ANALYSIS Addition of ECG to preparticipation screening saves 2.06 life-years per 1000 athletes at an incremental total cost of

International application of a new probability algorithm for the diagnosis of coronary artery disease

89 per athlete and yields a cost-effectiveness ratio of