In heart failure with preserved ejection fraction (HFpEF), what is a common symptom due to fluid backup?

In heart failure with preserved ejection fraction (HFpEF), a common symptom due to fluid backup is peripheral edema. This condition occurs when the heart is unable to effectively pump blood, leading to increased pressures in the blood vessels. As a result, fluid leaks into surrounding tissues, particularly in the lower extremities, causing swelling or edema. Patients often notice this swelling in their feet, ankles, or legs, which signifies that the heart's inability to manage blood flow is causing fluid accumulation.

The other options represent outcomes that would not typically occur in the context of HFpEF. Increased urine output and enhanced exercise capacity would be more characteristic of other conditions or situations, as heart failure generally leads to reduced exercise tolerance and can cause fluid retention rather than increased urinary output. Rapid weight loss would also be uncommon as patients with HFpEF generally experience weight gain due to fluid retention rather than loss. Therefore, peripheral edema is the hallmark symptom of fluid backup in this type of heart failure.