Exercise Cardiovascular Magnetic Resonance In Heart Failure With Preserved Ejection Fraction

This study uses a special type of heart scan (cardiac MRI) done during exercise to better understand heart failure in people whose heart pumps normally but still causes symptoms — a condition called HFpEF (heart failure with preserved ejection fraction). It also includes people with breathing problems that are NOT heart-related, and healthy volunteers for comparison. **You may be eligible if...** - You have been diagnosed with HFpEF (heart failure where the pumping function is normal or near normal) - You have unexplained breathlessness that has been tested and found NOT to be from heart failure - You are a healthy person with no history of breathlessness or exercise intolerance **You may NOT be eligible if...** - You have a pacemaker, metal implant, or other reason you cannot have an MRI - You are unwilling or unable to exercise during the MRI scan - You have had a heart failure hospitalization in the last 30 days - You have frequent irregular heartbeats that would affect scan quality Talk to your doctor to see if this trial is right for you.