In the second trimester to early third trimester, which changes occur in the heart?

In the second trimester to early third trimester, which changes occur in the heart?

• A. Increase in end-diastolic volume and physiologic dilation of the left ventricle
• B. Decrease in end-diastolic volume
• C. Decrease in left ventricular mass
• D. Systolic dysfunction

Answer: (A)

In pregnancy, the heart adapts to a higher blood volume. By the second trimester and into early third, plasma volume expansion increases preload, so the heart receives more venous return. The left ventricle stretches to accommodate this greater volume, leading to an increase in end-diastolic volume and physiologic dilation of the left ventricle. This preload-driven change allows stroke volume and cardiac output to rise while the heart’s contractile function remains normal. So the best choice reflects the preload-related enlargement: end-diastolic volume increases along with left ventricular dilation. The other options don’t fit this physiology: preload does not decrease, left ventricular mass does not typically decrease (it may increase modestly due to volume load), and systolic function remains preserved rather than showing dysfunction.

In pregnancy, the heart adapts to a higher blood volume. By the second trimester and into early third, plasma volume expansion increases preload, so the heart receives more venous return. The left ventricle stretches to accommodate this greater volume, leading to an increase in end-diastolic volume and physiologic dilation of the left ventricle. This preload-driven change allows stroke volume and cardiac output to rise while the heart’s contractile function remains normal.

So the best choice reflects the preload-related enlargement: end-diastolic volume increases along with left ventricular dilation. The other options don’t fit this physiology: preload does not decrease, left ventricular mass does not typically decrease (it may increase modestly due to volume load), and systolic function remains preserved rather than showing dysfunction.