TY - CHAP M1 - Book, Section TI - Cardiovascular Changes During Pregnancy A1 - Bashore, Thomas M. A1 - Granger, Christopher B. A1 - Jackson, Kevin P. A1 - Patel, Manesh R. A2 - Papadakis, Maxine A. A2 - McPhee, Stephen J. A2 - Rabow, Michael W. A2 - McQuaid, Kenneth R. PY - 2022 T2 - Current Medical Diagnosis & Treatment 2022 AB - Normal physiologic changes during pregnancy can exacerbate symptoms of underlying cardiac disease even in previously asymptomatic individuals. Maternal blood volume rises progressively until the end of the sixth or seventh month. Stroke volume increases over the same time course as a result of the volume change and an increase in LVEF. The latter reflects predominantly a decline in peripheral resistance due to vasodilation and the low-resistance shunting through the placenta. The heart rate then rises in the third trimester to further increase the cardiac output as the stroke volume maximizes out. Overall, cardiac output increases by 30–50%, peaking (and remaining constant) at about the 14th week; systolic BP tends to rise slightly or remain unchanged, but diastolic pressure falls significantly as afterload on the ventricle declines. Venocaval compression of the inferior vena cava from the gravid uterus can lead to reduced venous return and a lower cardiac output in the supine position. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1184696624 ER -