- Patients with decompensated heart failure; presence of any comorbidity such as: unstable angina; associated neurological disease; moderate respiratory illness to severe pre-diagnosed by the attending physician; active infectious disease or fever; disabling peripheral vascular disease; unstable ventricular arrhythmias; diabetes mellitus; use of cardiac pacemaker, musculoskeletal disease that limits physical activity, patients with a BMI ≥30.