A 42-year-old-woman is admitted to the hospital because of s

A 42-year-old-woman is admitted to the hospital because of syncopal attacks and difficulty breathing. She had undergone mitral valve replacement 8 years ago. X-ray shows pulmonary congestion and an enlarged heart. A phonocardiogram did not show a systolic murmur. Pressure tracings from the aorta, left ventricle, and left atrium are shown in the diagram. Which of the following diagnoses best accounts for these findings?


A. Aortic regurgitation

B. Aortic stenosis

C. Mitral regurgitation

D. Mitral stenosis

Answer is D.

It is evident that the patient has mitral obstruction because the left atrial pressure is greater than the left ventricular pressure toward the end of diastole, when blood is flowing from the left atrium into the left ventricle. The mitral valve replaced 8 years ago had undergone thrombosis resulting in obstruction of the mitral orifice. The very high left atrial pressure resulting from the thrombosed valve has caused pulmonary edema, which accounts for the dyspnea.

The aortic pressure and left ventricular pressure tracings are nearly superimposed during systole in the diagram, which eliminates the possibility of aortic regurgitation (choice A) or aortic obstruction (choice B).

Mitral regurgitation (choice C) is characterized by a greatly elevated left atrial pressure toward the end of systole. The increase in pressure is caused by backward flow of blood from the left ventricle into the left atrium through the leaky mitral valve. The leak occurs during systole, and is characterized by a systolic murmur, which was not noted in the patient. The left atrial pressure is normal at the end of diastole with mitral regurgitation because blood flows unimpeded from the atrium into the ventricle when the mitral valve is open.