What clinical sign is indicative of pulmonary congestion in heart failure?

Orthopnea is a clinical sign that indicates pulmonary congestion, particularly in patients with heart failure. It refers to the difficulty in breathing when lying flat and is a result of increased fluid accumulation in the lungs due to decreased cardiac output and congestion. This typically occurs because lying down redistributes body fluids, which can exacerbate pulmonary congestion, leading to a sensation of breathlessness.

In heart failure, the heart's inability to pump effectively can lead to fluid backing up in the lungs, creating a symptomatology that includes shortness of breath when the patient is supine. This is why orthopnea is a key indicator of pulmonary congestion and a common complaint among individuals with heart failure.

Other symptoms associated with pulmonary congestion, such as a dry cough or wheezing, may be present but are not as specific as orthopnea. Abdominal pain does not directly indicate pulmonary congestion and could stem from different conditions unrelated to heart failure.