What effect does heart failure have on preload?

In heart failure, preload is increased due to fluid retention. This occurs because the failing heart is unable to pump blood effectively, leading to a backlog of blood in the venous system. As more blood accumulates, it prompts the kidneys to retain sodium and water in an attempt to compensate for the decreased cardiac output. This fluid retention raises the volume of blood returning to the heart, which in turn increases preload.

Elevated preload can have several consequences on cardiac function, including increased workload on the heart and potential worsening of symptoms such as pulmonary congestion. Understanding this relationship between heart failure and preload is crucial in managing patients, as therapies often aim to reduce excess fluid volume to alleviate the symptoms associated with increased preload.