From the Guidelines
In preeclampsia, cardiac output may be either reduced or increased, while peripheral vascular resistance is typically increased due to widespread vasoconstriction. The changes in cardiac output and peripheral vascular resistance in preeclampsia are complex and can vary from one individual to another 1.
Key Points
- Cardiac output in preeclampsia can be either reduced or increased, which is different from normal pregnancy where cardiac output typically increases 1.
- Peripheral vascular resistance is usually increased in preeclampsia due to endothelial dysfunction and vasoconstriction 1.
- Fluid balance should aim for euvolemia, and insensible losses should be replaced to avoid risks of pulmonary edema 1.
Hemodynamic Changes
The hemodynamic changes in preeclampsia can lead to target organ damage, including renal dysfunction, cerebral edema, and placental insufficiency.
- The increased peripheral vascular resistance in preeclampsia is thought to be due to endothelial dysfunction, increased sensitivity to vasopressors, and release of anti-angiogenic factors 1.
- The combination of changes in cardiac output and peripheral resistance explains the characteristic hypertension seen in preeclampsia 1.
Clinical Implications
The management of preeclampsia should focus on controlling blood pressure and preventing target organ damage.
- Intravenous antihypertensives may be needed to control blood pressure, particularly if it becomes severe 1.
- Fluid management should aim for euvolemia, and patients should be monitored closely for signs of pulmonary edema or other complications 1.
From the Research
Changes in Cardiac Output and Peripheral Vascular Resistance in Preeclampsia
- Cardiac output and peripheral vascular resistance are affected in preeclampsia, with studies showing varying results depending on the presence of fetal growth restriction 2, 3, 4.
- In preeclampsia without fetal growth restriction, cardiac output is often high, while peripheral vascular resistance is low 4, 5.
- In contrast, preeclampsia with fetal growth restriction is associated with low cardiac output and high peripheral vascular resistance 2, 4.
- The changes in cardiac output and peripheral vascular resistance are not related to gestational age at onset, but rather to the presence or absence of fetal growth restriction 4.
- Vascular dysfunction, including endothelial dysfunction and increased peripheral resistance, is a key feature of preeclampsia 3, 6.
Factors Influencing Cardiac Output and Peripheral Vascular Resistance
- Fetal growth restriction is a significant factor influencing cardiac output and peripheral vascular resistance in preeclampsia, with low cardiac output and high peripheral vascular resistance observed in its presence 2, 4.
- The underlying pathology of preeclampsia, including placental ischemia and the release of pro- and antiangiogenic factors, contributes to vascular dysfunction and altered cardiac output and peripheral vascular resistance 3, 6.
- Antihypertensive agents, which act by reducing cardiac output or peripheral vascular resistance, may be used to treat preeclampsia, but their effectiveness depends on the underlying cardiovascular phenotype 4.