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 In individuals over 21 years of age, reevaluation should be done every 5 years. Tissue Doppler imaging should be performed to differentiate HCM from physiological or pathological cardiac hypertrophy (e.g. hypertension). An exercise echo stress test should be used in asymptomatic patients who do not show significant gradients at rest or with the Valsalva maneuver. Recommendation grade: IIa. Evidence level: C. 4.1.2.2.2. Transesophageal Doppler Echocardiogram Patients with an inadequate transthoracic window. Transesophageal Doppler echocardiogram is used to assess valve damage and the mechanism and magnitude of mitral regurgitation when this is unclear after transthoracic ECG. Intraoperative evaluation for myomectomy and alcohol septal ablation. Recommendation grade: I. Evidence level: B. To clarify the mechanism of atypical mitral regurgitation. Recommendation grade: IIa. Evidence level: B. 4.1.2.3. Cardiac Magnetic Resonance Imaging Cardiac magnetic resonance imaging (CMRI) is used to evaluate patients with suspected HCM when an ECG is inconclusive. Although ECG is the first imaging choice for patients with suspected HCM, this method may be limited by poor acoustic windows, particularly for areas such as the cardiac apex. 107 CMRI can also be used in highly suspicious cases that are not confirmed by ECG. Its excellent spatial resolution provides exclusive information about cardiac muscle and tissue, helping in the differential diagnosis of secondary causes of hypertrophy, such as amyloidosis and sarcoidosis. This examination allows the visualization of subtle changes in the thickness and contractility of the LV over time, as well as the detection of fibrotic areas, and recent studies have reported the presence and amount of fibrosis with prognosis. 107,108 CMRI is used to evaluate athletes with ECG abnormalities that are suspicious of HCM and inconclusive ECG findings. Recommendation grade: I. Evidence level: B. CMRI should be used for myocardial fibrosis screening in every athlete with suspected HCM. Recommendation grade: IIa. Evidence level: B. 4.1.2.4. Exercise Tests and Hypertrophic Cardiomyopathy The exercise stress testing is an independent means of identifying patients at increased risk of SD. Since the presence of marked ST-segment changes in HCM patients may indicate ischemia but not necessarily heart disease, the exercise stress testing has little diagnostic value. However, it could be a prognostic marker to be taken into consideration, especially when associated with expired gas measurements (CPET). 109,110 For these patients, a ramp protocol should be used first. This test avoids sudden changes in the recruitment of neuromuscular motor units and the metabolic changes associated with incremental protocols due to the constant and continuous increase of external work. The slope of the ramp should be individualized to last, preferably, from 8 to 12 minutes. 109 4.1.2.4.1. Exercise Testing Recommendations for Patients with Hypertrophic Cardiomyopathy The exercise stress testing is recommended for asymptomatic HCM patients who do not present high risk criteria as an associated element in prognostic stratification. Exercise stress testing is recommended for asymptomatic patients without high risk criteria, but who wish to participate in recreational physical activity. It is an additional element in differential diagnosis between athlete’s heart syndrome and HCM. Recommendation grade: I. Evidence level: B. The exercise stress testing can be used for patients with doubtful symptoms that are not associated with other high-risk criteria (preferably CPET). Table 8 - Factors indicative of athlete's heart syndrome (vs. HCM) in athletes with left ventricular hypertrophy in the "gray zone" (i.e., wall thickness: 13-15 mm) Clinical No family history Absence of diffuse T-wave inversion in ECG Nuclear magnetic resonance Homogeneous distribution of left ventricular hypertrophy No late gadolinium enhancement (fibrosis) Echocardiogram Increased left ventricular diameter (LVDD > 55 mm) Symmetrical hypertrophy (septum, posterior wall, apex and base) Normal diastolic function (E/A ratio > 1, peak velocity to E' > 11.5 cm/s) Hypertrophy regression after detraining No HCM-causing mutations found in genetic analysis LVDD: left ventricular diastolic diameter; ECG: electrocardiogram; HCM: hypertrophic cardiomyopathy. 340