Which finding best explains the cough and orthopnea seen in left‑sided heart failure?

• A. Increased pulmonary vascular congestion
• B. Tricuspid insufficiency
• C. Left ventricular hypertrophy
• D. Decreased peripheral vascular resistance

Answer: (A)

Cough and orthopnea in left‑sided heart failure come from backup of pressure into the lungs. When the left ventricle can’t eject blood effectively, pressure rises in the left atrium and pulmonary veins, pushing fluid out into the interstitium and alveoli—pulmonary congestion and edema. This fluid buildup irritates airways and impairs gas exchange, producing a chronic cough and dyspnea. Orthopnea specifically occurs because lying flat increases venous return to the heart, worsening the pulmonary congestion and making breathing harder; sitting up or propping up the upper body reduces venous return and eases symptoms. Tricuspid insufficiency involves the right heart and tends to cause systemic venous congestion rather than pulmonary edema. Left ventricular hypertrophy is a structural change that can contribute to heart failure, but it doesn’t directly explain the classic pulmonary symptoms. Decreased peripheral vascular resistance isn’t the mechanism behind coughing or orthopnea.