1,721,029 research outputs found
Hemodynamic guided treatment of hypertensive disorders in pregnancy: is it time to change our mind?
No full textFetal growth restriction and maternal cardiac function
No full textCardiac output rises in pregnancy, and most of this increase occurs in the first trimester. Both heart rate and stroke volume contribute to this increase, which, coupled with a decrease in mean arterial pressure, determines a reduction of maternal total vascular resistance (TVR) in physiological pregnancy. The absence of a 'correct' maternal cardiovascular compensatory response (absence of increase in cardiac output, heart rate, stroke volume, left ventricular mass and decrease in maternal TVR), in addition to abnormal trophoblastic invasion, might be one of the factors that could determine a reduced placental perfusion and, eventually, the development of fetal intrauterine growth restriction (IUGR). In fact, pregnancies complicated by IUGR appear to lack the stimulus to induce the hemodynamic changes typically present in physiological pregnancy such as the increase in preload, maternal heart rate, stroke volume, the enlargement of the left atrium and, above all, the reduction of TVR. It is difficult to establish whether these hemodynamic alterations found in IUGR patients develop from the early stages of pregnancy, but if future studies are able to support this hypothesis, this will open the opportunity to identify patients in a preclinical state and eventually treat them with new pharmacological protocol
Pre-eclampsia: One name, two conditions - The case for early and late disease being different
No full textThe identification of a patient simply as "preeclamptic" on the basis of elevated blood pressure and proteinuria is not sufficient to express the real haemodynamic adaptation of that mother. The importance of measuring cardiac output, stroke volume and total vascular resistance (TVR) is increasingly consistent with bedside observations from these patints. Clinicians should understand that to differentiate between the types of pre-eclampsia they should try to obtain as much information from the heart and cardiovascular system of the mother. The presence of elevated TVR characterizes more frequently the early "placental" PE. The presence of reduced TVR characterizes more frequently the late "metabolic" PE. These data, and not only the blood pressure alone, will help in the choice of the best treatment to be utilized in the effort of gaining days or weeks to induce foetal lung maturation and prepare the best possible maternal and neonatal conditions at birth. © 2013 Cambridge University Press
Restricted physical activity and maternal rest improve fetal growth: should we look for the reason in the cardiovascular modifications?
No full textIntrauterine growth restriction seems to be characterized
by a high-resistance, low cardiac output state that is detectable
at 22 to 24 weeks’ gestation in the preclinical stages of the
disease.2 This cardiovascular profile seems to be present at
different degrees of expression in the early and the late forms
of the disease. The low cardiac output may be because of 2
main reasons, namely the hypovolemic state and the possible
mechanical compression of the inferior vena cava.
During physical activity, the blood flow may be redirected
to the muscles. In case of normal plasma volume expansion
and maternal cardiovascular performance, physical activity
may have no effect on placental perfusion and fetal growth. If
plasma volume is not adequate and cardiac output is lower
than it should be, the redirection of part of the blood flow to
the muscles might steal precious blood from the placenta
Total vascular resistance and left ventricular morphology as screening tools for complications in pregnancy
Full text linkWe evaluated the predictive value of elevated total vascular resistance on the outcome of pregnancy in normotensive high-risk primigravidas with bilateral notching of the uterine artery Doppler. A total of 526 high-risk primigravidas referred to the obstetrics outpatient clinic of Tor Vergata University with bilateral notching of the uterine artery at 20 to 22 weeks' gestation were submitted to a maternal echocardiographic examination and uterine artery Doppler evaluation at 24 weeks' gestation. Blood pressure was recorded at the time of the examination, total vascular resistance was calculated, and the geometric pattern of the left ventricle was assessed. Patients were followed until the end of pregnancy to detect fetal/maternal adverse outcomes (gestational hypertension, preeclampsia, abruptio placentae, fetal growth restriction, perinatal death, etc). A total of 111 of the 526 pregnancies showed a bilateral notch at 24 weeks' gestation, and 97 had an adverse outcome (18.44%). The best independent predictor for maternal and fetal complications was total vascular resistance (odds ratio: 91.25; 95% CI: 39.64 to 210.05; P<0.001). The cutoff value was 1400 dynes·s·cm, with a sensitivity and a specificity of 89% and 94%, respectively. A high relative wall thickness of the left ventricle (>0.37; odds ratio: 2.47; 95% CI: 1.12 to 5.44) and a hypertrophized ventricle (left ventricular mass >130 g; odds ratio: 2.52; 95% CI: 1.12 to 5.64) were also independent predictors (P<0.05). Echocardiography might identify at 24 weeks' gestation patients who subsequently develop maternal and fetal complications through the assessment of maternal hemodynamics and left ventricular geometry. © 2008 American Heart Association, Inc
Early and Late preeclampsia: Two different maternal hemodynamic states in the latent phase of the disease
Full text linkBecause early and late preeclampsia (PE) are thought to be different disease entities, we compared maternal cardiac function at 24 weeks gestation in a group of normotensive asymptomatic patients with subsequent development of early (<34 weeks gestation) and late (≥34 weeks gestation) PE (blood pressure >140/90+proteinuria >300 mg/dL) to detect possible early differences in the hemodynamic state. A group of 1345 nulliparous normotensive asymptomatic women underwent at 24 weeks gestation uterine artery Doppler evaluation and maternal echocardiography calculating total vascular resistance. In the subsequent follow-up 107 patients showed PE: 32 patients had late and 75 had early PE. Five of 32 patients with late PE and 45 of 75 patients with early PE had bilateral notching of the uterine artery at 24 weeks (15.6% versus 60.0%; P<0.05). Total vascular resistance was 1605 ±248 versus 739±244 dyn · s · cm-5, and cardiac output was 4.49± 1.09 versus 8.96± 1.83 L in early versus late PE (P<0.001). Prepregnancy body mass index was higher in late versus early PE (28 ±6 versus 24 ±2 kg/m2; P<0.001). Early and late PE appear to develop from different hemodynamic states. Late PE appears to be more frequent in patients with high body mass index and low total vascular resistance; earlier forms of PE appear to be more frequent in patients with lower BMI and with bilateral notching of the uterine artery. These findings support the hypothesis of different hemodynamics and origins for early PE (placental mediated, linked to defective trophoblast invasion with high percentage of altered uterine artery Doppler) and late PE (linked to constitutional factors such as high body mass index). © 2008 American Heart Association, Inc
Pregnancy complications in chronic hypertensive patients are linked to pre-pregnancy maternal cardiac function and structure
No full textBACKGROUND:
Chronic hypertension complicates around 3% of all pregnancies and is associated with an increased risk for pregnancy complications such as superimposed preeclampsia, fetal growth restriction, preterm delivery, and stillbirth, reaching a rate of complications of up to 25-28%.
OBJECTIVE:
We performed an echocardiographic study to evaluate pre-pregnancy cardiac geometry and function, along with the hemodynamic features of treated chronic hypertension patients, searching for a possible correlation with the development of feto-maternal complications and with pre-pregnancy therapy.
MATERIALS AND METHODS:
This was a prospective observational cohort study of 192 consecutive patients receiving treatment for chronic hypertension (calcium channel blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, β-blockers, α1-adrenoceptor antagonists, and/or diuretics). Patients underwent echocardiography before pregnancy, assessing left ventricular morphology and function, cardiac output, and total vascular resistance. Pre-pregnancy therapy was noted, patients were shifted to α-methyldopa right before pregnancy, and were followed until delivery, noting major early (<34weeks' gestation) and late (≥34 weeks' gestation) complications. Comparisons among the 3 groups (ie, those with no complications, early complications, and late complications) were performed with 1-way analysis of variance with Student-Newman-Keuls correction for multiple comparisons. The Mann-Whitney U test was used for non-normally distributed data. Comparison of proportions was used as appropriate. Receiver operating characteristic curve analysis was used to identify cutoff values of diastolic dysfunction in this population using the E/e' ratio, and separate cutoff of values for total vascular resistance for the prediction of early and late complications of pregnancy. Binary univariate and multivariate logistic regression as well as Cox proportional hazards regression were used to evaluate the possible correlation among angiotensin-converting enzyme inhibitor/angiotensin receptor blocker and/or calcium channel blocker pre-pregnancy therapy, cardiovascular features, and the risk for subsequent early and late complications of pregnancy.
RESULTS:
Of 192 patients, 141 had no complications, and 51 had a complicated pregnancy (24 had early complications and 27 had late complications). Concentric geometry was more frequent in those women with early versus late and no complications (50% vs 13.5% and 11.1%, respectively; P < .05), whereas eccentric hypertrophy was more represented in women with late versus early and no complications (32% versus 12.5% and 1.4%, respectively; P < .05). The receiver operating characteristic curve showed an E/e' ratio value >7.65 (sensitivity, 59.6%; specificity, 68.6%) as a predictor of subsequent complications of pregnancy, whereas total vascular resistance <1048 (sensitivity, 83.7%; specificity, 55.6%) was predictive for late complications and total vascular resistance >1498 (sensitivity, 87.5%; specificity, 78.0%) for the early complications of pregnancy. Univariate analysis showed that the following parameters were predictive for complications of pregnancy: altered geometry of the left ventricle (odds ratio, 5.94; 95% confidence interval, 2.90-12.19), diastolic dysfunction (odds ratio, 3.22; 95% confidence interval, 1.63-6.37), altered total vascular resistance (odds ratio, 3.52; 95% confidence interval, 1.78-6.97), and pre-pregnancy therapy without calcium channel blockers/angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (odds ratio, 2.73; 95% confidence interval, 1.37-5.42). These parameters, except for altered total vascular resistance, were independent predictors in the multivariate analysis corrected for body mass index, heart rate, parity, and mean arterial pressure.
CONCLUSION:
Chronic hypertension patients with pre-pregnancy cardiac remodeling and dysfunction more often develop early and late complications of pregnancy. Pre-pregnancy therapy for chronic hypertension patients with calcium channel blockers and/or angiotensin-converting enzyme inhibitors/angiotensin receptor blockers may positively influence cardiac profiles and the outcome of a future pregnancy with a reduced rate of complications
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