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 Table 4 – Main differences between exercise stress testing and cardiopulmonary exercise testing Exercise testing Variable Exercise stress testing Cardiopulmonary exercise testing Functional capacity Measured Measured Maximum aerobic power Estimated Measured Anaerobic threshold Undetermined Determined V/Q Ratio Not evaluated Evaluated Inotropic response Limited evaluation Excellent evaluation Mechanical Efficiency Presumed Measured Protocol More dependent Less dependent True maximum cardiorespiratory capacity Presumed Probable/identified Etiology of dyspnea Unidentified Probable/identified V/Q ratio: ventilation/perfusion ratio. 2.3.3.3. Heart Rate Chronotropic incompetence indicates a poor prognosis and has been associated with endothelial dysfunction, altered autonomic modulation, elevated inflammatory markers and CAD. An inadequate HR response can be considered as the inability to achieve 85% of the estimated maximum HR. The following equation can be used to predict maximum HR: 208 - (age × 0.70). A chronotropic index < 80% is another way to identify chronotropic incompetence, which has prognostic value. It is obtained by the following ratio: (HR reserve obtained/estimated HR reserve) × 100. 56 Vagal modulation of HR can be inferred from HR reduction in the first minute of recovery in relation to HR at peak exertion. This observation was initially identified when comparing athletes with heart failure (HF) patients. 57,58 Reductions ≤ 12 beats per minute have been associated with higher mortality rates. 59 2.3.3.4. Cardiac Arrhythmias Less complex cardiac arrhythmias, such as occasional ventricular extrasystoles during an exercise stress testing, often express an increase in sympathetic autonomic modulation due to graduated exercise. Such conditions alone, without other alterations, do not justify limiting the activity of asymptomatic individuals, nor do they require further investigation. Symptomatic or asymptomatic patients who develop complex ventricular arrhythmias, such as ventricular tachycardia (whether sustained or not), must be investigated before they return to training. For mild-to-moderate intensity leisure activities in asymptomatic individuals with a cardiovascular risk factor: performan exercise stress testing at the beginning of participation. Recommendation grade: III. Evidence level: C. For amateur athletes participating in high-intensity sports and competition: perform exercise stress testing at the beginning of training. Recommendation grade: IIa. Evidence level: A. For professional athletes participating in high-intensity athletic activity and competition: perform an exercise stress testing at the beginning of the season. Recommendation grade: I. Evidence level: C. Any time: When a patient refers to chest pain or discomfort, fatigue or dyspnea of unknown cause, palpitations, or when previously non-existent arrhythmias, exercise-related pre-syncope or syncope or elevated resting BP (with or without compromise a target organ) are identified: perform an exercise stress testing. Recommendation grade: I. Evidence level: A. 2.3.4. Cardiopulmonary Exercise Testing For a long time (including in Brazil), athletes and individuals participating in high-performance activities have undergone cardiopulmonary exercise testing (CPET) to evaluate performance and prescribe aerobic training. 60 As described in Table 4, CPET differs from an exercise stress testing by adding measures and analyses of expired gases. 61 Unlike in exercise tests for clinical diagnosis, when CPET is performed in apparently healthy athletes BP is often not measured and even ECG is often not performed, and HR is obtained by frequency meter. With so much equipment available (e.g., in laboratories, clinics, hospitals, clubs and sports centers) to perform these measures, there is little sense in evaluating an athlete’s aerobic condition through a exercise stress testing, which has an error rate of approximately 20% when estimates based on formulas developed for clinical protocols involving treadmills or cycle ergometers are used. In certain clinical settings and for certain groups of athletes, including a CPET in PPS may be recommended (or even critical for) individual risk stratification, especially due to the data collected from expired gas measurement and analysis. This could be relevant in master athletes, in individuals with cardiovascular and/or pulmonary diseases who are involved in recreational competition (e.g. half-marathons, marathons, mountain climbing, cycling, water sports, etc.), as well as in professional athletes. In these circumstances and whenever possible, it is best to use an exercise stress testing that closely approximates the patient’s sport. Among the additional clinical information that CPET can reveal about athletes or active, healthy individuals, two types stand out: (a) more precise and objective identification of limiting factor(s) for maximum effort (cardiovascular, respiratory and muscular or metabolic) and (b) evaluation of systolic volume behavior, which is obtained by analysis of the curves and maximal values of oxygen pulse (VO 2 /HR) 335