Accuracy and precision of USCOM versus transthoracic echocardiography before and during pregnancy

Reference ranges for third-trimester maternal cardiovascular function parameters measured in normotensive pregnant women using a non-invasive cardiac output monitor: A study based on data from the prospective PEACH cohort study

OBJECTIVE

We defined reference ranges for maternal cardiac output, systemic vascular resistance, and stroke volume measured in the third trimester of pregnancy using the Ultrasound Cardiac Output Monitor 1A.

DESIGN

Based on data from the prospective PEACH (PreEclampsia, Angiogenesis, Cardiac dysfunction and Hypertension) cohort study.

SETTING

Rigshospitalet and Hvidovre Hospital, Denmark.

SAMPLE

Normotensive pregnant women aged 18-45 years with singleton pregnancies, enrolled in the PEACH study in 2016-2018.

METHODS

We modelled cardiac output, systemic vascular resistance and stroke volume as a function of gestational age using multilevel linear models with fractional polynomials.

MAIN OUTCOME MEASURES

Unconditional and conditional reference ranges for cardiovascular parameters measured in gestational weeks 28-40.

RESULTS

Our study cohort included 405 healthy pregnant women who contributed 1210 cardiovascular function measurements for analysis. Maximum cardiac output and stroke volume values were measured in gestational weeks 30-32 and decreased over the third trimester, whereas systemic vascular resistance increased during the same period. We created reference ranges for eight combinations of maternal height, age and parity. We also created a simple calculator to allow for implementation of the reference ranges in clinical practice.

CONCLUSIONS

Our reference ranges allow the use of a bedside ultrasound device to non-invasively assess cardiac function in pregnancy and identify women at risk of complications. The unconditional ranges allow clinicians to evaluate isolated measurements and identify women needing follow-up. The conditional ranges incorporate information from previous measurements and improve monitoring over time.

Maternal Hemodynamics from Preconception to Delivery: Research and Potential Diagnostic and Therapeutic Implications: Position Statement by Italian Association of Pre-Eclampsia and Italian Society of Perinatal Medicine

OBJECTIVE

 The Italian Association of Preeclampsia (AIPE) and the Italian Society of Perinatal Medicine (SIMP) developed clinical questions on maternal hemodynamics state of the art.

STUDY DESIGN

 AIPE and SIMP experts were divided in small groups and were invited to propose an overview of the existing literature on specific topics related to the clinical questions proposed, developing, wherever possible, clinical and/or research recommendations based on available evidence, expert opinion, and clinical importance. Draft recommendations with a clinical rationale were submitted to 8th AIPE and SIMP Consensus Expert Panel for consideration and approval, with at least 75% agreement required for individual recommendations to be included in the final version.

RESULTS

 More and more evidence in literature underlines the relationship between maternal and fetal hemodynamics, as well as the relationship between maternal cardiovascular profile and fetal-maternal adverse outcomes such as fetal growth restriction and hypertensive disorders of pregnancy. Experts agreed on proposing a classification of pregnancy hypertension, complications, and cardiovascular states based on three different hemodynamic profiles depending on total peripheral vascular resistance values: hypodynamic (>1,300 dynes·s·cm-5), normo-dynamic, and hyperdynamic (<800 dynes·s·cm-5) circulation. This differentiation implies different therapeutical strategies, based drugs' characteristics, and maternal cardiovascular profile. Finally, the cardiovascular characteristics of the women may be useful for a rational approach to an appropriate follow-up, due to the increased cardiovascular risk later in life.

CONCLUSION

 Although the evidence might not be conclusive, given the lack of large randomized trials, maternal hemodynamics might have great importance in helping clinicians in understanding the pathophysiology and chose a rational treatment of patients with or at risk for pregnancy complications.

KEY POINTS

· Altered maternal hemodynamics is associated to fetal growth restriction.. · Altered maternal hemodynamics is associated to complicated hypertensive disorders of pregnancy.. · Maternal hemodynamics might help choosing a rational treatment during hypertensive disorders..

Associations between Maternal Nutritional Status, Hemodynamic Parameters, and Delivery Outcomes in Low-Risk Pregnancies: A Prospective Observational Study

Maternal nutritional status represents a pivotal predictor of pregnancy outcome. This prospective observational study investigates the associations between maternal characteristics and nutritional habits at term, hemodynamic parameters, and pregnancy outcomes. Healthy women with singleton uncomplicated pregnancies were enrolled at 36-41 gestational weeks. At enrollment, a nutritional score (0-10) was calculated in order to quantify maternal adherence to a healthy diet and lifestyle. Maternal hemodynamic parameters were assessed by using the Ultrasonic Cardiac Output Monitor (USCOM), including cardiac output (CO), systemic vascular resistance (SVR) and Smith-Madigan inotropy index (SMII). Pregnancy outcomes were recorded at delivery. Associations between maternal characteristics and nutritional score, hemodynamic parameters, and pregnancy outcomes were investigated by using multi-adjusted generalized linear models. In total, 143 pregnancies were enrolled. Pregestational body mass index (BMI) was positively associated with SVR, and negatively associated with CO and SMII. Additionally, a positive association was detected between the nutritional score and SMII. Finally, CO was positively associated with birth and placental weight, while RVS showed a negative association with birth and placental weight. This study shows that maternal derangements in nutritional status and habits are associated with a compromised hemodynamic profile at term, with additional impacts on intrauterine growth.

The prediction of hypertensive disorders by maternal hemodynamic assessment in the first trimester of pregnancy

BACKGROUND

Hypertensive disorders of pregnancy and fetal growth restriction share common etiopathological origins and could be caused by maternal hemodynamic maladaptation to pregnancy.

OBJECTIVE

The aim of our study is to evaluate if there is a correlation between maternal hemodynamic detected by UltraSonic Cardiac Output Monitor (USCOM^®) during the first trimester and the pregnancy outcome.

STUDY DESIGN

We recruited a nonconsecutive series of women in the first trimester of pregnancy with no previous history of hypertensive disorders. We measured the pulsatility index uterine arteries and performed a hemodynamic evaluation by USCOM^® device. After delivery, we reported the development of hypertensive disorders or intrauterine fetal growth restriction later during gestation.

RESULTS

A total of 187 women were enrolled during the first trimester; 17 (9%) developed gestational hypertension or preeclampsia while 11 (6%) delivered a restricted growth fetus. Mean uterine artery pulsatility index above the 95th percentile was significantly more frequent in both women who developed hypertension and those with fetal growth restriction compared to controls. Hemodynamic parameters (reduced cardiac output and increased total vascular resistance) were significantly different in the group that developed hypertensive disorders, compared to uncomplicated pregnancy. ROC curves demonstrated the usefulness of uterine artery pulsatility index in the prediction of fetal growth restriction, while hemodynamic parameters were significantly associated to the development of hypertensive disorders.

CONCLUSIONS

Hemodynamic maladaptation to pregnancy may predispose to the development of hypertension, while we demonstrated a significative relationship between growth restriction and mean uterine pulsatility index. Further studies are needed to assess the value of hemodynamics evaluation in screening protocols of preeclampsia.

Assessing maternal cardiac function by obstetricians: technique and reference ranges

BACKGROUND

A strong body of evidence has now coalesced indicating that some obstetrical syndromes may result from maladaptive responses of the maternal cardiovascular system. Longitudinal studies have shown that these changes are complex and present before the clinical recognition of preeclampsia and fetal growth restriction, suggesting that hemodynamic maladaptation may play an etiologic role in obstetrical complications. Chronic hypertension is one of the most frequent complications of pregnancy, and recent evidence suggests that control of mild hypertension in early pregnancy improves outcome. The management of chronic hypertension can be improved by understanding specific cardiovascular hemodynamic abnormalities such as increased cardiac output or increased systemic vascular resistance, which can respond to either beta or calcium channel blockers, depending on the hemodynamic findings. Evaluation of maternal cardiac function has not been previously available to obstetrical healthcare providers using diagnostic ultrasound equipment used for fetal evaluation.

OBJECTIVE

Obstetrical ultrasound machines may be configured for various probes (endovaginal, abdominal, 3D/4D, and cardiac). This study used a cardiac probe placed in the suprasternal notch to image and measure the descending aorta diameter and the velocity time integral using pulsed and continuous wave Doppler ultrasound in normal pregnant women between 11 and 39 weeks of gestation. These measurements were followed by computation of maternal left ventricular preload, afterload, contractility, and blood flow.

STUDY DESIGN

This was a prospective cross-sectional study. A total of 400 pregnant women were recruited between 11 and 39 weeks of gestation. Imaging of the maternal aortic arch was performed by placing a cardiac probe in the suprasternal notch to identify the aortic arch using 2D and color Doppler ultrasound. The end-systolic diameter of the aorta was measured at the junction of the left subclavian artery with the descending aorta, which was followed by insonation of the descending aorta to obtain the Doppler waveform. Following insonation of the descending aorta, measurements of the aortic diameter, velocity time integral, ejection time, mean pressure gradient, heart rate, maternal weight and height, and systolic and diastolic blood pressures were entered into an Excel spreadsheet to compute the following: (1) preload measurements of stroke volume, stroke volume index, and stroke work index; (2) afterload measurements of systemic vascular resistance and the potential-to-kinetic energy ratio; (3) contractility measurements of inotropy and the Smith-Madigan inotropy index; and (4) blood flow measurements of cardiac output and the cardiac output index. Fractional polynomial regression analysis was performed for each of the above measurements using gestational age as the independent variable.

RESULTS

The diastolic and mean arterial blood pressure decreased from 11 to 18 weeks of gestation and then increased until term. The afterload measurements demonstrated similar characteristics, as all values decreased from 11 weeks until the mid and late second trimester, after which all values increased until term. Changes in contractility demonstrated an increase from 11 weeks to 25 to 28 weeks, followed by a decline until term. Changes in blood flow demonstrated an increase from 11 to 27 weeks and then declined until term. The continuous wave Doppler values were greater than the pulsed Doppler values except for the contractility measurements. Examples of abnormal cardiac measurements were identified in pregnant patients with hypertension and fetal growth restriction. An Excel calculator was created to provide quick computation of z-score measurements and their corresponding centiles described in this study.

CONCLUSION

The technique for evaluation of maternal cardiac function described in this study would allow screening of maternal left ventricular preload, afterload, contractility, and blood flow in the obstetrical clinical milieu once a cardiac probe is acquired for obstetrical ultrasound machines used for fetal evaluation. The above measurements would allow the clinician to select appropriate hypertensive medication on the basis of the results of the evaluation of the maternal left ventricle.

Early Assessment of Cardiac Function by Echocardiography in Patients with Gestational Diabetes Mellitus

Objective

To offer a baseline for clinical diagnosis, echocardiography was performed to evaluate the disparities in heart function comparing pregnant women with diabetes mellitus (GDM) and ordinary pregnant women.

Methods

A prospective case-control study is being conducted on pregnant women with or without gestational diabetes. The sample size for both the intervention and control groups is the same: no diabetes diagnosis or previous forms, a single pregnancy, and no issues (such as preeclampsia or fetal growth restriction). The females were all subjected to routine echocardiograms to examine the morphology and function of their left and right hearts.

Results

In the research, 51 women with GDM and 50 healthy controls volunteered. Women with GDM had a significantly higher heartrate (82 ± 9 vs. 74 ± 8), left ventricular (LV) relative wall thickness (0.39 ± 0.06 vs. 0.31 ± 0.07; P < 0.001), LV early diastolic transmitral valve velocity (E) (0.79 ± 0.14 vs. 0.72 ± 0.13 m/s; P = 0.031), and LV late diastolic implementing regulations valve velocity (0.6). Speckle-tracking analysis showed significant decrease in LV right ventricular (RV). A study indicated a reduced pulmonary acceleration time (59 ± 9 vs. 68 ± 12 ms; P = 0.001), RV E/A ratio (1.21 ± 0.19 vs. 1.31 ± 0.31; P = 0.022), and a greater RV myocardial systolic annular velocity (0.17 ± 0.03 vs. 0.12 ± 0.03; P = 0.023).

Conclusions

Our results revealed that the heart function of diabetic pregnant women differed considerably from that of the control group, such as LV-RWT, LV diastolic transmitral valve speed, and LV late diastolic transmitral valve speed. Given these results, further research into the postpartum cardiovascular healing of pregnant women with gestational diabetes mellitus is required.

Hypertensive disorders and maternal hemodynamic changes in pregnancy: monitoring by USCOM® device

Hypertensive disorders are quite common, complicating about 10% of pregnancies, while preeclampsia occurs in 2-8% of cases. The most recognized etiopathogenetic factor for the development of preeclampsia is deficient remodeling of the spiral arteries during trophoblastic invasion. Recently, some authors speculated about the "cardiovascular origin of preeclampsia"; in particular, they postulate that placental dysfunction is not the primum movens of preeclampsia, but it could be caused by a failure of the maternal cardiovascular system to adapt to the pregnancy itself. Moreover, several studies have also shown that developing preeclampsia in pregnancy is associated with an increased risk of cardiovascular disease later in life. Due to the importance of this pathology, it would be crucial to have an effective screening in order to implement a prophylaxis; for this purpose, it could be useful to have an accurate and noninvasive device for the assessment of maternal hemodynamic variables. USCOM^® (Ultrasonic Cardiac Output Monitor) is a noninvasive Doppler ultrasonic technology which combines accuracy, reproducibility, noninvasiveness, and a fast learning curve. Maternal hemodynamic evaluation is important in order to monitor the changes that the maternal organism encounters, in particular a reduction in blood pressure, a decrease in total peripheral resistances, and an increase in cardiac output, resulting in a hyperdynamic circle. These hemodynamic modifications are lacking in pregnancies complicated by preeclampsia. For these reasons, it is crucial to have a tool that allows these parameters to be easily evaluated in order to identify those women at higher risk of hypertensive complications and more severe outcomes.

Temporal haemodynamic changes after bisoprolol treatment in patients with uncontrolled hypertension

Background

Anti-hypertensive drugs are widely used to control blood pressure, yet their effects on haemodynamics, especially in Chinese populations, and the potential for non-invasive methods to monitor these changes, are poorly understood. This study aimed to determine the early and late effects of bisoprolol treatment on blood pressure, cardiac output (CO), stroke volume (SV), heart rate (HR), systematic vascular resistance (SVR), and inotropy measured in Chinese patients with hypertension.

Methods

Twelve Chinese subjects (median age: 55 years, interquartile range: 52-58 years; 33% male) with uncontrolled hypertension were recruited at the Prince of Wales Hospital in Hong Kong and haemodynamic measurements were assessed using a non-invasive Ultrasonic Cardiac Output Monitor (USCOM). Seven hourly measurements were taken before and after bisoprolol 2.5 mg on day 1 (T0 to T6), and in nine patients this was repeated six weeks later (TF0 to TF6). Any BP change of 5 mmHg was considered clinically significant and P<0.05 was considered statistically significant.

Results

On day 1 (N=12), there was a significant drop in median CO [4.9 (4.7-5.6) vs. 3.8 (3.3-4.7) L/m², P<0.0001] associated with a compensatory increase in SVR [1,698.1 (1,584.6-1,894.3) vs. 2,222.6 (1,777.4-2,712.5) d·s·cm^-5, P<0.0001] at T2. The median dBP {92 [87-95] vs. 86 [79-89] mmHg, P=0.0002} and MAP {110 [104-114] vs. 104 [101-109] mmHg, P=0.038} reduced significantly 6 hours after bisoprolol treatment. Except for HR, all other measured haemodynamics returned to baseline at T6. On week 6 (N=9), SVR was generally reduced, but major parallel swings in CO and SVR were still evident. All patients showed a trend to lower blood pressure, SVR, and inotropy (P<0.05), but HR, SV, and CO returned to baseline values after 6 weeks treatment (P>0.05).

Conclusions

The acute haemodynamic changes between 6 hours of the first dose and the dose after 6 weeks of bisoprolol treatment are similar. Long-term therapy can effectively reduce blood pressure by reducing SVR.

Usefulness of USCOM® evaluation in women with chronic hypertension who developed severe preeclampsia with low platelets and elevated liver enzymes

Cardiovascular changes that occur during pregnancy have been recently described and are matter of debate; during gestation we observe an increase in cardiac output and a reduction of peripheral total vascular resistance (TVR). In pregnancies complicated by hypertensive disorders, instead, these changes are lacking, with a persisting low cardiac output and high peripheral resistances. In this case report, we observed that in patients with chronic hypertension TVR are high, while the cardiac output is able to face the needs of pregnancy. The increase in TVR before the decision to deliver, due to bad blood pressure control despite therapy, may precede the alterations in blood tests (platelet decreasing and high liver enzymes). This data may be useful for monitoring patients with chronic hypertension and identifying those at higher risk of developing HELLP/severe preeclampsia.

A Physiologic Approach to Hemodynamic Monitoring and Optimizing Oxygen Delivery in Shock Resuscitation

The approach to shock resuscitation focuses on all components of oxygen delivery, including preload, afterload, contractility, hemoglobin, and oxygen saturation. Resuscitation focused solely on preload and fluid responsiveness minimizes other key elements, resulting in suboptimal patient care. This review will provide a physiologic and practical approach for the optimization of oxygen delivery utilizing available hemodynamic monitoring technologies. Venous oxygen saturation (SvO₂) and lactate will be discussed as indicators of shock states and endpoints of resuscitation within the framework of resolving oxygen deficit and oxygen debt.