1. inability to perform a maximal baseline exercise test 2. structural heart disease, valve heart disease, or diastolic dysfunction estimated by 2-dimensional echocardiography 3. patients with previous ischemic heart disease, heart failure, myocardiopathy, or myocarditis 4. effort angina or signs of ischemia during cpet 5. significant primary pulmonary disease, including a history of pulmonary arterial hypertension, chronic thromboembolic pulmonary disease, or chronic obstructive pulmonary disease (g) treatment with digitalis, calcium channel blockers, β-blocker or ivabradine (h) patients with chronic kidney disease (glomerular filtration rate \<60ml/min/1.73m2) (i) patients with pacemakers or previous history of atrial fibrillation; (j) patients with autoimmune, inflammatory or active neoplastic disease k) anemia (l) pregnancy.

1. inability to perform a maximal baseline exercise test 2. structural heart disease, valve heart disease, or diastolic dysfunction estimated by 2-dimensional echocardiography 3. patients with previous ischemic heart disease, heart failure, myocardiopathy, or myocarditis 4. effort angina or signs of ischemia during cpet 5. significant primary pulmonary disease, including a history of pulmonary arterial hypertension, chronic thromboembolic pulmonary disease, or chronic obstructive pulmonary disease (g) treatment with digitalis, calcium channel blockers, β-blocker or ivabradine (h) patients with chronic kidney disease (glomerular filtration rate \<60ml/min/1.73m2) (i) patients with pacemakers or previous history of atrial fibrillation; (j) patients with autoimmune, inflammatory or active neoplastic disease k) anemia (l) pregnancy.

inability to perform a maximal baseline exercise test structural heart disease, valve heart disease, or diastolic dysfunction estimated by 2-dimensional echocardiography patients with previous ischemic heart disease, heart failure, myocardiopathy, or myocarditis effort angina or signs of ischemia during cpet significant primary pulmonary disease, including a history of pulmonary arterial hypertension, chronic thromboembolic pulmonary disease, or chronic obstructive pulmonary disease (g) treatment with digitalis, calcium channel blockers, β-blocker or ivabradine (h) patients with chronic kidney disease (glomerular filtration rate <60ml/min/1.73m2) (i) patients with pacemakers or previous history of atrial fibrillation; (j) patients with autoimmune, inflammatory or active neoplastic disease k) anemia (l) pregnancy.

inability to perform a maximal baseline exercise test structural heart disease, valve heart disease, or diastolic dysfunction estimated by 2-dimensional echocardiography patients with previous ischemic heart disease, heart failure, myocardiopathy, or myocarditis effort angina or signs of ischemia during cpet significant primary pulmonary disease, including a history of pulmonary arterial hypertension, chronic thromboembolic pulmonary disease, or chronic obstructive pulmonary disease (g) treatment with digitalis, calcium channel blockers, β-blocker or ivabradine (h) patients with chronic kidney disease (glomerular filtration rate <60ml/min/1.73m2) (i) patients with pacemakers or previous history of atrial fibrillation; (j) patients with autoimmune, inflammatory or active neoplastic disease k) anemia (l) pregnancy.