ABC | Volume 114, Nº5, May 2020

Arq Bras Cardiol. 2020; 114(5):943-987 Guidelines Brazilian Cardiovascular Rehabilitation Guideline – 2020 Another meta-analysis actually reported a lower likelihood of shocks during follow-up in patients participating inCVR compared to controls, corroborating the previous result of an observational study, which reported a higher incidence of ICD activation in patients who did not participate in CVR programs. 341,345 One possible explanation or the lower incidence of arrhythmias and shocks in patients undergoing CVR would be the improvement of physical capacity, as it has been previously documented that greater physical fitness is associated with a lower incidence of arrhythmia. 16,17,346 In addition, exercise could reduce myocardial arrhythmogenicity due to remodeling and reduction of sympathetic excitability. 347 In a nationwide study with 10 years of follow-up which included 150 patients with ICDs in a CVR program, all of which completed a CPET or TMET to support exercise prescription, there were only three shock events and all were appropriate. 348 This provides additional evidence of the safety of stress testing and CVR in this population. 6.8.2. When Is Cardiovascular Rehabilitation Indicated? Physical exercise can and should be indicated as long as the patient’s clinical condition is stable and clinical treatment is optimized. In addition to the potential beneficial effects on underlying heart disease, CVR increases physical fitness and can help reduce the incidence of arrhythmias and, consequently, of ICD activation (Table 11). 6.8.3. Pre-Exercise Evaluation In patients with implantable devices, the clinician must become familiar with the reason for implant placement, the patient’s ventricular function, whether any arrhythmias are present and, particularly, the device settings and parameters. For patients with an artificial pacemaker, this means understanding the programming mode, the set HR limits, and the type and response of the activity sensor. In patients with an ICD, essential information includes the HR threshold which has been set to trigger shock or burst therapies. In addition to the standard clinical examination, pre‑exercise evaluation is of paramount importance in these patients. Ideally, a CPET or TMET should be performed to determine functional capacity and analyze the behavior of the device during exertion. However, the impossibility of performing CPET or TMET should not prevent the practice of physical exercise. In these cases, monitoring during sessions may reveal a need for device reprogramming, usually of maximum HR and sensor response settings. During CVR sessions, continuous ECG monitoring can be achieved with the use of telemetry systems. HR control devices, such as regular cardiac monitors, can also be used for monitoring CVR sessions. 350 However, due to changes in the ECG tracing caused by artificial pacing, automated HR measurement both by ECG telemetry systems and by cardiac monitors may be erroneous. The team should be aware of this potential for error and measure HR manually as needed. 6.8.4. Special Considerations for the Prescription and Follow-Up of Physical Exercise Programs When prescribing and defining intensity limits for aerobic physical training, one should be aware of ICD programming and limit the intensity accordingly to 10–20 bpm below the HR set to trigger therapy (shock or burst). This is especially Table 10 – Abnormalities observed on cardiopulmonary exercise test or treadmill exercise test that should limit exercise intensity in patients with valvular heart disease Exercise-induced changes Description Signs and symptoms Onset of angina, angina equivalent, or other signs and symptoms indicative of exercise intolerance Blood pressure Plateau response or decline in SBP; or, SBP >220 mmHg; or, DBP >115 mmHg ST segment Onset of ST segment depression (horizontal or descending) >1 mm Ventricular function Evidence of decreased ventricular function on exertion or onset of moderate to major left ventricular wall motion abnormalities Pulse O 2 (CPET only) Evidence of early plateau or decline on effort despite increased load Arrhythmia Grade 2 or 3 AV block, atrial fibrillation, supraventricular tachycardia, complex ventricular arrhythmias CPET: cardiopulmonary exercise test; SBP: systolic blood pressure; DBP: diastolic blood pressure, AV: atrioventricular. Table 11 – Indications for physical exercise and other treatments in patients with implantable cardioverter–defibrillators Indication Recommendation Level of evidence Physical exercise to increase physical capacity in stable patients with an ICD 341,342 I A Physical exercise for potential reduction of the incidence of ICD activation (shocks) 341 IIa B Use of neuromuscular electrical stimulation in patients with implantable devices with bipolar sensors, when performed on muscles far from the implant site 349 IIb B ICD: implantable cardioverter–defibrillator. If any structural heart disease is present, the corresponding recommendations should be taken into account. 971