USMLE Q Bank Step 1- 196

A 54 year old man presents to the emergency room complaining of progressive shortness of breath for 3 weeks. He has a long history of left sided heart failure treated by enalapril. Chest x-ray reveals bilateral pulmonary edema. After receiving the appropriate treatment, he is hospitalized for further investigations.

Which of these findings is most likely revealed after further investigations?

A-Normal arterial O2 partial pressure

B-Normal arterial CO2 partial pressure

C-Normal respiratory function tests

D-Decreased pulmonary artery pressure

E-Increased pulmonary venous pressure


Decreased left ventricular contractility due to left ventricular heart failure leads to increased end-diastolic pressure in the left ventricle which leads to increased pulmonary venous pressure. It also leads to increased pulmonary artery pressure. Arterial O2 and Co2 partial pressure should be affected due to lung edema and defective inflation. Respiratory function tests are affected for the same reason.

The correct answer is E

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