What is a key indicator of end-stage heart failure?

Persistent fatigue and weakness are key indicators of end-stage heart failure. As heart failure progresses, the heart's ability to pump blood effectively diminishes, leading to reduced oxygen delivery to the body's tissues. This results in a significant decrease in exercise tolerance, where even minimal activities can lead to fatigue and weakness. Patients may feel constantly tired and unable to perform daily activities that they once managed with ease.

In contrast, increased exercise tolerance would indicate an improvement in physical capacity, which is not typical in end-stage heart failure. Heart rate variability, while it can provide information about autonomic function and overall heart health, does not specifically indicate the severity of heart failure. Normal blood pressure levels may also be misleading in the context of heart failure, as some patients may maintain normal blood pressure even with significant heart dysfunction. Therefore, persistent fatigue and weakness serve as reliable and direct indicators of the advanced stage of heart failure, reflecting the overall decline in cardiac output and energy levels in the patient.