The nurse expects that a client with mitral stenosis would demonstrate symptoms associated with congestion in the:
A. Aorta
B. Right atrium
C. Superior vena cava
D. Pulmonary circulation
Correct Answer: D. Pulmonary circulation
When mitral stenosis is present, the left atrium has difficulty emptying its contents into the left ventricle. Hence, because there is no valve to prevent backward flow into the pulmonary vein, the pulmonary circulation is under pressure.
Option A: The mitral valve is a bileaflet valve positioned between the left atrium and left ventricle. The normal mitral orifice area is 4 to 6 square centimeters. Under normal physiologic conditions, the mitral valve opens during the left ventricular diastole to allow blood to flow from the left atrium to the left ventricle. The pressure in the left atrium and the left ventricle during diastole are equal.
Option B: The left ventricle gets filled with blood during early ventricular diastole. There is only a small amount of blood that remains in the left atrium. With the contraction of the left atrium (the “atrial kick”) during late ventricular diastole, this small amount of blood fills the left ventricle.
Option C: Mitral valve areas less than 2 square centimeters causes an impediment to the blood flow from the left atrium into the left ventricle. This creates a pressure gradient across the mitral valve. As the gradient across the mitral valve increases, the left ventricle requires the atrial kick to fill with blood.
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