In Vivo Quantitative Mapping of Mitochondrial Cardiac Membrane Potential in Heart Failure

Inclusion Criteria: * Active participants: 1. ≥40 years old 2. LVEF ≥50% 3. Body Mass Index \<35kg/m2 4. NYHA fuctional class I 5. Engaged in aerobic exercise (running cycling or swimming) for ≥3 days per week or 5 hours per week without extensive layoff over the previous 6 months 6. Non-smoker ≥1 year 7. Fasting glycemia \<6.0 mmol/L 8. HbA1c \<5.7% * Sedentary participants: 1. ≥40 years old 2. LVEF ≥50% 3. Body Mass Index \<35kg/m2 4. NYHA fuctional class 5. ≤1 structured physical activity per week 6. Non-smoker ≥1 year 7. Fasting glycemia \<6.0 mmol/L 8. HbA1c \<5.7% * HFpEF participants: 1. Chronic symptomatic HF and LVEF \>40% within 12 months before the screening visit (regardless of the imaging modality) 2. One of the following abnormalities: 1. HF requiring hospitallization and IV diuretics within 12 months of study entry 2. NTproBNP \>150 pg/ml in sinus rhythm 3. NTproBNP \>450 pg/ml in chronic atrial fibrillation Exclusion Criteria: * for all participants : 1. Infiltrative CMP (e.g., cardiac amyloidosis) 2. Hypertrophic CMP 3. Dilated CMP 4. Ischemic CMP with myocardial infarction 5. Other chronic diseases or medications that may interfere with mitochondrial function 6. Primary severe valvular disease 7. Pericardial disease 8. Pacemaker 9. Defibrillator 10. Congenital heart disease 11. History of cardiac transplant 12. BMI \>45 kg/m2 13. High resting blood pressure ≥150/90 mmHg 14. Estimated glomerular filtration rate (eGFR) \<50 mL/min/1.73m2 15. Iodinated contrast allergy 16. Women of child bearing potential 17. Pregnancy 18. Breastfeeding 19. Inability to undergo the imaging logistics 20. Any condition that, in the opinion of the investigator, could compromise the participation in the study