Left ventricular rotational characteristics in healthy mid-term pregnancy—insights from the three-dimensional speckle-tracking echocardiographic MAGYAR-Preg Study

Introduction

Significant changes in cardiovascular physiology develop even during healthy pregnancy. Haemodynamic, neurohormonal, plasma volume, haematological and structural cardiac changes occur to varying degrees depending on the trimester (1-5). The left ventricle (LV) is characterized by a complex architecture of endocardial and epicardial muscle bands arranged perpendicularly with obliquely running fibers. During the cardiac cycle, these fibers undergo a three-dimensional (3D) deformation pattern, while simultaneously exhibiting spatial rotational mechanics as well. Specifically, during systole, the LV base rotates clockwise and the LV apex rotates counterclockwise, creating a motion similar to wringing a towel referred to as LV twist (6-10). Recently developed 3D speckle-tracking echocardiography (3DSTE) has proven to be a validated and suitable method for quantifying these LV rotations and the resulting LV twist (11-15). However, literature data is contradictory regarding LV rotational mechanics in healthy pregnancy, therefore, the purpose of this observational cross-sectional study was to compare apical and basal LV rotations and LV twist in healthy subjects in the second trimester with those of age-matched non-pregnant women using 3DSTE. We present this article in accordance with the STROBE reporting checklist (available at https://qims.amegroups.com/article/view/10.21037/qims-2026-1-0138/rc).

Methods

The initial study population consisted of 27 healthy subjects in mid-term pregnancy; however, 6 cases were excluded due to suboptimal image quality. Consequently, the final analytical cohort comprised 21 subjects [mean age: 30.7±2.7 years, weight: 80.0±15.6 kg, height: 167.5±6.6 cm, body mass index (BMI): 29.3±6.9 kg/m², heart rate: 83.2±2.3 1/s, systolic blood pressure: 124.2±2.3 mmHg, diastolic blood pressure: 82.3±3.3 mmHg]. The pregnant women were recruited from those attending prenatal care at the Department of Obstetrics and Gynecology, University of Szeged, Hungary, between 2021 and 2026. This group was compared to a control group of 27 age-matched healthy non-pregnant volunteers (mean age: 28.4±6.0 years, weight: 58.9±7.9 kg, height: 164.6±6.2 cm, BMI: 21.9±3.2 kg/m², heart rate: 81.0±1.9 1/s, systolic blood pressure: 118.2±4.2 mmHg, diastolic blood pressure: 78.3±4.3 mmHg). Their data were selected from a large pool containing data from healthy controls. Exclusion criteria for all control participants included known medical conditions, disorders or pathologies, ongoing pharmacological treatment, obesity, active smoking, or professional athleticism, as these factors could potentially confound the results. All participants exhibited laboratory, electrocardiographic (ECG), and two-dimensional (2D) Doppler echocardiographic parameters within physiological limits. Comprehensive 2D Doppler echocardiography and data acquisition with 3DSTE was utilized concurrently in both groups, strictly adhering to current clinical guidelines and standardized protocols. This observational cross-sectional study is a component of the Motion Analysis of the heart and Great vessels bY three-dimensionAl speckle-tRacking echocardiography in Pregnancy (MAGYAR-Preg) Study. This ongoing research initiative aims to characterize pregnancy-related 3DSTE-derived myocardial and valvular abnormalities (“Magyar” translates to “Hungarian” in the Hungarian language). The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by Institutional and Regional Human Biomedical Research Ethics Committee of University of Szeged (Nos. 71/2011 and 145/2021). Informed consent was given by all participants.

2D Doppler echocardiography

All healthy pregnant and non-pregnant individuals involved in the study underwent a comprehensive 2D Doppler echocardiographic evaluation. Standard measurements were obtained for left atrial and LV internal dimensions, and the LV ejection fraction (LV-EF) was calculated using the modified Simpson’s biplane method. All echocardiographic examinations were performed using a Toshiba Artida^TM ultrasound system (Toshiba Medical Systems, Tokyo, Japan) equipped with a PST-30BT (1–5 MHz) phased-array transducer. Valvular pathologies were assessed and quantified according to current clinical guidelines together with assessment of mitral inflow E and A velocities and their ratio by Doppler (16).

3DSTE

Following the 2D Doppler echo study, 3DSTE was performed in all participants using the same Toshiba Artida^TM system, equipped with a PST-25SX matrix-array transducer. The 3DSTE procedure consisted of two distinct phases: image acquisition and offline analysis. First, 3D echocardiographic datasets were acquired from the apical window with the subject in the left lateral decubitus position. Despite the altered respiratory mechanics associated with pregnancy, all participants were able to achieve consistent end-expiratory breath-holds. This was performed in a standardized manner. To ensure optimal image quality, six wedge-shaped subvolumes were captured using ECG gating; these were automatically merged by the software to reconstruct a comprehensive full-volume 3D dataset. In the second phase, offline analysis was conducted using the vendor-specific 3D Wall Motion Tracking software (version 2.7, Ultra Extend, Toshiba Medical Systems). Image quality was qualitatively assessed based on the clarity of endocardial border definition across all segments. Datasets exhibiting significant acoustic dropouts or stitching artifacts that compromised speckle tracking were excluded. Overall image quality was graded using a 5-point Likert scale (1: poor, 5: excellent); a minimum score of 3 was mandatory for inclusion in the final analysis. A virtual 3D reconstruction of the LV was performed to enable the quantification of LV end-diastolic and end-systolic volumes (EDV and ESV, respectively) and rotational mechanics throughout the cardiac cycle. Using standard apical long-axis views and multiple short-axis planes (basal, mid-ventricular, and apical), the mitral annular-LV edges and the endocardial surface of the LV apex were manually identified. Following a step-by-step automated tracking process, a 3D virtual LV model was generated (Figure 1). The features of the rotational mechanics of the LV were assessed included:

• Basal LV rotation (clockwise, expressed in degrees);
• Apical LV rotation (counterclockwise, expressed in degrees);
• LV twist, defined as the net difference between apical and basal rotations (expressed in degrees);
• Time-to-peak LV twist (expressed in milliseconds).

Figure 1 Representative LV-focused 3D analysis is shown in a healthy pregnant. The panel displays apical four-chamber (A) and two-chamber (B) views, alongside apical (C1), mid-ventricular (C2), and basal (C3) short-axis planes, all automatically extracted from the acquired 3D dataset. The reconstructed 3D virtual model of the LV is illustrated in (D), while (E) presents the calculated LV volumetric parameters and ejection fraction. The time-apical and basal LV rotation curves are shown in (F). Apical LV rotation in a counterclockwise direction is represented by the solid yellow arrow, while the dashed yellow arrow illustrates clockwise basal LV rotation. EDV, end-diastolic volume; EF, ejection fraction; ESV, end-systolic volume; LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.

In instances where apical and basal LV rotations occurred in the same counterclockwise or clockwise direction, the condition was defined as LV ‘rigid body rotation’ (RBR). In these cases, no calculation of the LV twist was possible; instead, the apico-basal LV rotational gradient (the absolute difference between apical and basal LV rotations) was determined (12,17).

Statistical analysis

Continuous data are reported as mean ± standard deviation, and categorical data as numbers and percentages. Data normality was assessed using the Shapiro-Wilk test. For continuous variables, group comparisons were performed using the independent samples t-test or the Mann-Whitney U test, as appropriate. For multiple group comparisons, one-way analysis of variance (ANOVA) was used. Categorical data were compared using Fisher’s exact test. Correlations were assessed using Pearson’s correlation coefficients. To evaluate intra- and interobserver variability for LV rotational parameters, intraclass correlation coefficients (ICCs) were calculated from 25 randomly selected healthy individuals. A two-way mixed-effects model for absolute agreement was employed, comparing full acquisitions with offline re-analyses. The time interval between analyses was minimal, as assessments were performed during the same session. A P value of less than 0.05 was considered statistically significant. All statistical analyses were conducted using SPSS software (version 22.0; IBM Corp., Armonk, NY, USA).

Results

Clinical and demographic data

At the time of the examination, the mean maternal age of the 21 healthy pregnant subjects was 30.7±2.7 years, while the mean gestational age was 22.1±5.9 weeks. All pregnancies resulted in delivery. The mean gestational age at delivery was 39.0±1.1 weeks. There were 14 male and 6 female neonates, and the mean birth weight was 3429±520 grams (in one case, neonatal data was not available).

LV volumes and rotational mechanics

In three pregnant subjects, complete LV-RBR was present (3 of 21, 14%), the remaining 18 subjects showed normally directed LV rotational mechanics (18 of 21, 86%). A significant reduction in apical LV rotation and LV twist could be detected in healthy pregnant individuals as compared with non-pregnant subjects. Basal LV rotation did not differ significantly between the two groups. Time to peak apical LV twist tended to be shorter in pregnant women; however, this difference did not reach statistical significance (Table 2). In three pregnant cases presenting LV-RBR, apical LV rotations proved to be 6.4, 8.5, and 12.9 degrees, respectively. Basal LV rotation for the same subjects proved to be 1.7, 5.3, and 1.4 degrees, respectively, suggesting counterclockwise LV-RBR in all cases. The consequent LV apico-basal gradient proved to be 4.7, 3.2, and 11.5, degrees, respectively. LV end-systolic volume and thickness of the interventricular septum and LV posterior wall were lower and LV-EF higher in individuals with LV-RBR (Tables 1,2).

Correlations

No correlations could be demonstrated between LV twist and LV-EDV (r=0.02, P=0.93), LV-ESV (r=−0.03, P=0.92), LV-EF (r=0.09, P=0.73) and E/A (r=0.07, P=0.83). No correlations were present between gestational age and any of LV rotational parameters, as well.

Intra- and interobserver variability analysis

Intra- and interobserver ICCs were 0.85, 0.86, and 0.85, and 0.85, 0.84, and 0.83 for basal and apical LV rotations and LV twist, respectively.

Discussion

Pregnancy is known to be associated with significant changes in cardiovascular physiology, which vary in severity depending on the trimester (2-5). The second trimester of pregnancy is a pivotal phase of hemodynamic transition, defined by extensive physiological adaptations to optimize uteroplacental perfusion. A hallmark of this period is the substantial rise in cardiac output, which typically peaks between the 24th and 26th weeks of gestation. This augmentation is primarily mediated by an expanded stroke volume and a progressive increase in maternal heart rate. Concurrently, the maternal vasculature undergoes significant remodeling. Systemic vascular resistance reaches its nadir during this trimester, driven by the vasodilatory effects of progesterone and nitric oxide, alongside the establishment of the low-resistance uteroplacental circuit. This systemic vasodilation induces a characteristic decline in both systolic and diastolic blood pressure, typically reaching a plateau mid-pregnancy before gradually returning to pre-gestational levels in the third trimester. Furthermore, the second trimester is characterized by a marked expansion of plasma volume that exceeds the rise in red blood cell mass, resulting in physiological hemodilution. To accommodate this sustained volume overload, the LV undergoes eccentric hypertrophy, evidenced by increased LV end-diastolic dimensions and myocardial mass. Although these structural and functional shifts are physiological, they require precise regulatory mechanisms to preserve maternal cardiovascular stability while facilitating fetal development (2-5).

LV rotational mechanics represent a complex, 3D deformation pattern essential for optimal cardiac pump function. The cardiac motion stems from the helical fiber architecture: subendocardial fibers follow a right-handed helical pattern, whereas subepicardial fibers follow a left-handed one. During systole, this counter-directional arrangement results in a ”towel-wringing” motion, where the LV base rotates clockwise and the apex rotates counterclockwise when viewed from the apex. Numerous conflicting results have been reported regarding LV rotational mechanics in healthy pregnancy. Recent investigations have demonstrated that LV twist and torsion do not differ significantly between women in their second trimester (22–26 weeks of gestation) and non-pregnant controls. Furthermore, no significant alterations in LV twist were observed following sustained isometric forearm contraction (18). There was a significant increase in peak LV twist from non-pregnant controls (9.4±3.7°) to second-trimester (12.0±4.2°) and third-trimester subjects (12.6±5.9°) (1). In another study, peak LV twist increased significantly only in the third trimester of normal pregnancy (control: 13.02±5.28° vs. first:13.48±2.90°, second:13.12±3.30° and third: 16.83±3.61°). Changes in LV end-systolic volume from the 1st to the 3rd trimester showed an independent association with changes in LV twist (19). When non-pregnant, nulliparous pregnant women (22–26 weeks’ gestation), and primiparous postpartum women (12–16 weeks after delivery) were compared, LV twist was similar among the three groups (20). Furthermore, LV twist and torsion did not differ significantly between healthy pregnant women with a BMI of ≥35 kg/m² versus those with a BMI of ≤30 kg/m² (21). In contrast, LV twist was significantly higher in the first trimester compared with controls and remained constantly elevated throughout the remainder of pregnancy and puerperium (control: 11.5±4.3° vs. first: 13.5±5.6°, second: 13.6±6.1°, third: 13.8±4.3°, puerperium: 13.1±4.3°) (22). In the present 3DSTE study, significantly reduced LV twist due to decreased LV apical rotation was observed in healthy women in the second trimester (mid-pregnancy) compared with non-pregnant women (control: 13.1±3.4° vs. second trimester: 6.8±3.6°). A recent study identified myocardial strain impairment during healthy pregnancy, suggesting that this may not reflect intrinsic myocardial dysfunction. Instead, it is hypothesized to result from intraventricular dyssynchrony caused by a narrowed anteroposterior chest diameter and diaphragmatic elevation, leading to extrinsic myocardial compression (23). These factors should be taken into account when interpreting the current findings.

LV-RBR, defined by a near absence of LV twist, is typically observed in patients with LV non-compaction (LV-NC), cardiac amyloidosis, or acromegaly, with a reported prevalence of 6% in normal controls (17). There is currently no evidence in the literature of LV-RBR occurring during pregnancy, even in healthy individuals. Thus far, the presence of LV-RBR in the postpartum period has only been identified in a single case of postpartum cardiomyopathy associated with LV-NC (24). In the present study, the prevalence of LV-RBR in healthy mid-term pregnancy proved to be 3 of 21 (14%) (12,17). During subgroup analysis, although a small number of LV-RBR cases was examined, lower LV end-systolic volume could be detected as compared to that of individuals with normally directed LV rotational mechanics resulting in higher LV-EF which was accompanied with thinner LV walls as well. These findings warrant further investigation.

LV-EF values derived from 3DSTE tend to be lower than those obtained via conventional 2D echocardiography. This discrepancy arises because 3DSTE consistently underestimates LV volumes, with a more pronounced effect on LV-EDV than LV-ESV, thereby yielding lower LV-EFs. This LV volumetric underestimation stems from the lower spatial resolution of 3DSTE. Specifically, suboptimal image quality often precludes the clear differentiation of endocardial trabeculae from the myocardium, leading to their inclusion in the myocardial mass and a subsequent reduction in measured LV volumes (25,26).

LV rotational mechanics can be quantified in selected healthy pregnant subjects with adequate 3DSTE image quality. The results are conflicting with previous findings, which may partly be due to differences in diagnostic methodology. 3DSTE is a validated and widely accepted diagnostic tool for the quantification of LV rotational mechanics with well-defined normal reference values (11-15,27-29). Further studies are warranted to investigate the effects of pregnancy-associated pathologies (gestational diabetes, hypertension, eclampsia, etc.) on LV rotational mechanics.

Limitation section

The most important limitations are presented below:

• A noteworthy limitation is that 3DSTE-derived image quality is generally considered inferior to that of conventional 2D echocardiography. Due to its superior spatial and temporal resolution, 2D imaging maintains a distinct advantage over 3DSTE (11,12,27-29). Furthermore, the larger footprint of the 3DSTE transducer complicates optimal positioning. The multi-beat acquisition protocol—integrating six subvolumes—further introduces the risk of stitching artifacts and motion-related errors, potentially compromising the integrity and reliability of the data.
• While LV strain could have been measured using the existing 3D echocardiographic dataset, analyzing these parameters was considered beyond the intended scope of this specific study. Moreover, neither volumetric and strain analysis of other cardiac chambers, nor assessments of valvular dimensions were intended to be investigated in the present study.
• The validity of 3DSTE-derived rotational parameters is already well-established in clinical research, further validation of these parameters was not an objective of this investigation.
• Given the relatively modest sample size of the healthy cohort, the study may be statistically underpowered, thereby increasing the risk of type II errors despite high measurement reproducibility. Consequently, these findings should be regarded as exploratory and warrant validation through larger, multi-center investigations.
• The present study is limited by the small sample size of the healthy cohort and a relatively high exclusion rate due to suboptimal image quality. This has importance not only technical, but also methodologic, because it affects feasibility, sample selection, and the external reliability of the results. However, the excluded subjects did not differ from the analysed ones. Although a “healthy” cohort was examined, inter-individual differences in anthropometrics could represent a relevant source of heterogeneity, and partially explain findings.
• Furthermore, the statistical power could have been enhanced by adjusting for potential confounding factors.
• Given the limited sample size, the low observed prevalence of LV-RBR precludes definitive conclusions; however, these findings are noteworthy, as this is the first study to suggest that such a phenomenon may occur at this frequency even in healthy pregnancies.
• Finally, the use of a single-vendor system may imply a vendor-specific nature of the measurements. Moreover, speckle-tracking results are sensitive to image quality, tracking quality, and the analytical workflow, therefore interpretation of subtle functional differences should be cautious (30).

Conclusions

Reduced apical LV rotation and consequent LV twist with preserved basal LV rotation could be detected in healthy mid-term pregnancy. In some cases, counterclockwise LV-RBR was observed.

Acknowledgments

We thank all participants and their family for their support in the study.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://qims.amegroups.com/article/view/10.21037/qims-2026-1-0138/rc

Data Sharing Statement: Available at https://qims.amegroups.com/article/view/10.21037/qims-2026-1-0138/dss

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-2026-1-0138/coif). A.N. serves as an unpaid editorial board member of Quantitative Imaging in Medicine and Surgery. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by Institutional and Regional Human Biomedical Research Ethics Committee of University of Szeged (Nos. 71/2011 and 145/2021). Informed consent was given by all patients.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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