![]() ![]() ![]() When required, agitated saline contrast is generally felt to be safe during pregnancy (FDA Category B), though rigorous studies have not been performed for investigation of its use. In late pregnancy, cardiac output is estimated to be approximately 14% lower in the supine position as compared to the left lateral decubitus position, and approximately 8% of women will experience frank symptomatic hypotension while supine. Left lateral decubitus positioning is therefore preferred. An important distinction is that supine positioning can be challenging due to compression of the inferior vena cava (IVC) and pelvic veins by the gravid uterus, particularly after 20 weeks of gestation. Investigations to date have not reported any adverse effects from the utilization of diagnostic ultrasound, which is therefore utilized frequently in clinical practice. A key advantage to echocardiography in the context of pregnancy is its excellent safety profile. General approaches to image acquisition for pregnant women are similar to imaging protocols utilized for non-pregnant patients. Furthermore, it is widely available and does not require the use of radiation or intravenous contrast.Įchocardiographic imaging during pregnancy As such, echocardiography is a clinically invaluable tool for the evaluation of pregnant women both in the context of underlying cardiovascular disease and those without known pre-existing disease presenting with symptoms that are challenging to distinguish from uncomplicated pregnancy. Substantial overlap exists between symptoms that commonly accompany normal pregnancy and those that signal early manifestations of cardiovascular disease including hyperventilation (and associated dyspnea), anemia, weight gain, and edema. Thereafter, hemodynamic shifts occur rapidly in the first 2 postpartum weeks, though full return to pre-pregnancy hemodynamics occur over the first 6 postpartum months. SVR rapidly increases after delivery of the placental. Finally, systemic venous resistance (SVR) decreases due to maturation of the low resistance placental, which can result in a decrease in mean arterial pressure (MAP) in early pregnancy the SVR nadirs at approximately 24 weeks of gestation and then gradually increases thereafter. An increase in heart rate (which increases 10–20 beats per minute above pre-pregnancy values) contributes to the increase in cardiac output. There is a concomitant increase in red cell mass-though to a lesser extent than plasma volume expansion-which contributes to the physiologic anemia of pregnancy. Estrogen contributes to plasma volume expansion, which increases approximately 40% throughout pregnancy. ![]() Maternal cardiac output rises early in pregnancy and increases in sum approximately 30–50% for singleton pregnancies. Hemodynamic changes occurring in normal pregnancy. ![]()
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