Question:medium
Orthopnoea in congestive heart failure develops due to?
Orthopnoea in congestive heart failure develops due to?
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Lying flat shifts pooled blood centrally and the failing heart backs it up into the lungs.
Updated On: Jun 24, 2026
- Reservoir function of pulmonary veins
- Pooling of blood in lower limb veins
- Pulmonary hypertension
- Systemic hypertension
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The Correct Option is A
Solution and Explanation
Orthopnoea is dyspnoea that comes on specifically when the patient lies flat and eases when they sit or stand. It tends to appear later in the course of heart failure than breathlessness on exertion, and understanding it depends on what posture does to venous return.
When a person is upright, a substantial volume of blood sits in the dependent veins of the legs and in the splanchnic bed. Lying down removes the gravitational gradient, so this stored blood drains centrally and the venous return to the right heart and lungs rises over a few minutes.
A healthy left ventricle simply pumps this extra volume onward. A failing left ventricle cannot, so the additional blood accumulates upstream in the pulmonary venous system. The pulmonary veins behave as a reservoir and become congested, raising pulmonary capillary pressure and pushing fluid into the lung interstitium and alveoli.
This congestion stiffens the lungs and provokes breathlessness, which is why sitting up, by shifting fluid back to the periphery and lowering pulmonary venous pressure, brings relief. The central mechanism is the redistribution of blood with the reservoir function of the pulmonary veins.
\[\boxed{\text{Reservoir function of pulmonary veins}}\]
When a person is upright, a substantial volume of blood sits in the dependent veins of the legs and in the splanchnic bed. Lying down removes the gravitational gradient, so this stored blood drains centrally and the venous return to the right heart and lungs rises over a few minutes.
A healthy left ventricle simply pumps this extra volume onward. A failing left ventricle cannot, so the additional blood accumulates upstream in the pulmonary venous system. The pulmonary veins behave as a reservoir and become congested, raising pulmonary capillary pressure and pushing fluid into the lung interstitium and alveoli.
This congestion stiffens the lungs and provokes breathlessness, which is why sitting up, by shifting fluid back to the periphery and lowering pulmonary venous pressure, brings relief. The central mechanism is the redistribution of blood with the reservoir function of the pulmonary veins.
\[\boxed{\text{Reservoir function of pulmonary veins}}\]
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