ABC | Volume 112, Nº3, March 2019

Updated The Brazilian Society of Cardiology and Brazilian Society of Exercise and Sports Medicine Updated Guidelines for Sports and Exercise Cardiology - 2019 Arq Bras Cardiol. 2019; 112(3):326-368 family history or the presence of abnormal findings during physical examination. 35,36 Recommendation grade: I. Evidence level: A. 2.3.3. Exercise Stress Testing As part of a strategy for early cardiovascular disease identification, an exercise stress testing can be recommended for the initial evaluation of amateur or professional athletes of any age group. This test can contribute to the prognosis of asymptomatic patients or when there are symptoms potentially indicative of some pathological condition. 37,38 Its may also be used to evaluate cardiorespiratory fitness during training for certain sports, especially those with a predominantly aerobic component. 39,40 Asymptomatic individuals with no cardiovascular risk factors can be cleared without this examination. However, an exercise stress testing may be recommended in other conditions. 41 After 35 years of age, CAD is the main cause of mortality. An exercise stress testing is recommended for individuals in this age range, mainly to identify myocardial ischemia, since the results can indicate the probable presence of the disease. In asymptomatic individuals, and even in those with known CAD, exercise stress testing is used for prescribing an adequate level of physical activity. Changes in resting ECG, often due to physiological LVH, reduce the method’s accuracy for diagnosing myocardial ischemia. Simultaneous analysis of other examination variables contributes to a more global assessment. 42 When a patient mentions having palpitations during physical activity, this should be investigated with an exercise stress testing to reproduce the conditions of the complaint in a controlled environment. 2.3.3.1. Variables to be Evaluated in an Exercise Stress Testing 2.3.3.1.1. Functional Capacity Low functional capacity indicates a poor prognosis. A number of observational studies have demonstrated an inverse association between the metabolic equivalents reached in the exercise stress testing and mortality. 43-45 When an individual’s functional capacity is low compared to predicted values for his or her gender and age group, additional investigation may be necessary. 46 2.3.3.1.2. Chest Pain An exercise stress testing can reproduce the conditions of chest pain or discomfort during exercise and allows a probable diagnosis of myocardial ischemia due to CAD, which should lead to further investigation and suspension of training. When an exercise stress testing leads to non-ischemic pain similar to that which motivated the test, but there are no changes in any of the test variables, the probability of CAD is low and the athlete can return to competition. 47 On the other hand, chest pain characteristic of angina, even if unaccompanied by ST- segment changes, is usually associated with a poor prognosis. Proper interpretation of an exercise stress testing requires prior knowledge of normal findings for young athletes. Determining whether ST-segment depression in master athletes is related to CAD can be challenging. The possibility of a false positive result related to LVH cannot be ruled out, but ischemia of atherosclerotic origin should always be discarded. Additional investigation may be required before returning to practice and competition. 48 2.3.3.1.3. ST-T Segment ST-segment depression > 1 mm is suggestive of CAD, especially when in a horizontal or descending pattern. Such alterations have higher values when occurring concomitantly with chest pain or other manifestations that contribute to a diagnosis of myocardial ischemia. 49 ST-segment elevation ≥ 1 mm at 60 ms after J-point, when not observed in a Q-wave area (inactive zone), is very suggestive of subepicardial (or transmural) injury, 50 indicates ischemia and must be managed as such. In asymptomatic athletes, when ST alterations occur during an exercise stress testing, even if unaccompanied by chest pain, or when they occur with high double product values and high exercise capacity, especially if associated with frequent cardiac arrhythmias, training should be suspended (temporarily or not). In such cases, it is of fundamental importance to continue investigation into cardiovascular disease. Such an approach is based on the increased cardiovascular demand and increased risk of events during exercise, especially in individuals over 35 years of age or when one or more CAD risk factors are present. ST-segment analysis should consider: • Morphological characteristics, i.e., descending is more serious than horizontal, which is more serious than slow ascending. 51 • Early onset during exercise and persistent changes late in the recovery phase indicate greater risk and severity. 52 • ST-segment depression greater than 10% in relation to the immediately preceding R-wave amplitude. This adjustment in ST-segment evaluation should be considered due to recurring high-amplitude R-waves, which can express physiological LVH. 53 Furthermore, regarding the ventricular repolarization phase, it is important to point out that when starting from an altered ECG, normalization during exercise can indicate a good prognosis (if not accompanied by symptoms). 54,55 2.3.3.2. Blood Pressure Excessively high BP during an exercise stress testing in patients who have not been diagnosed with hypertension and who have normal resting levels could be a warning sign, because there is a significantly greater risk of developing hypertension in subsequent years. In patients with newly diagnosed hypertension, laboratory investigation and treatment should begin immediately. However, if there is a progressive decrease in systolic BP during an exercise stress testing, especially when it falls below the pre-effort value, subsequent investigation for heart disease should be carried out, especially in cases of stress-induced systolic dysfunction. 334