Introduction. Pregnancy is characterized by a significant expansion of plasma volume and an increase in cardiac output, necessitating structural and functional adaptations of the cardiac chambers, including the right atrium (RA). To evaluate these changes, three-dimensional (3D) speckle-tracking echocardiography (STE) was used as a validated and sophisticated modality for the concurrent assessment of RA volumetric and functional alterations. This study aimed to characterize RA volumes, volume-based functional indices, and strain parameters in healthy women during mid-gestation, compared with a cohort of non-pregnant controls. Methods. This retrospective cohort analysis included 20 healthy, asymptomatic women in their second trimester (mean age: 29.9 ± 3.0 years; weight: 81.2 ± 14.2 kg; height: 166.9 ± 5.8 cm; body surface area [BSA]: 1.95 ± 0.17 m²). The control group consisted of 30 age-matched healthy non-pregnant women (mean age: 29.9 ± 4.1 years; weight: 58.7 ± 6.5 kg; height: 166.0 ± 5.4 cm; BSA: 1.68 ± 0.11 m²). All subjects underwent comprehensive two-dimensional Doppler echocardiography and 3DSTE. Results. Early and late diastolic RA volumes were significantly reduced, despite preserved end-systolic RA volume. Pregnant subjects exhibited reduced active RA stroke volume and increased passive RA emptying fraction, while all other parameters remained comparable between the groups. No significant differences were observed between groups in end-systolic peak RA global or mean segmental strains, nor in RA strains measured during atrial contraction. However, end-systolic peak regional RA strain analysis revealed decreased basal RA circumferential strain (CS) and increased superior RA-CS in pregnant participants compared with controls. Furthermore, during late diastole (at atrial contraction), superior RA-CS, RA-3D strain, and RA-area strain were significantly higher in healthy pregnant subjects than in controls. Conclusions. Substantial regional changes in RA function were detected by 3DSTE, likely reflecting adaptation to pregnancy-induced plasma volume expansion, and resulting in significant RA volumetric changes.

Introduction: Gestational physiology is characterized by an expansion of plasma volume and an elevation in cardiac output. Given the scarcity of existing data on pregnancy-related left atrial (LA) volumetric and functional features, this study aims to define LA volumes, volume-based functional properties and strains in healthy subjects during mid-term pregnancy. Methods: The present study comprised 19 healthy women in mid-term pregnancy (mean age: 30.5 ± 2.7 years, weight: 81.7 ± 14.0 kg, height: 166.9 ± 5.7 cm) without any symptoms, known diseases or other conditions, which could affect the results. Their results were compared to those of 43 healthy non-pregnant women (mean age: 28.6 ± 4.9 years, weight: 59.9 ± 8.5 kg, height: 167.8 ± 7.6 cm). All participants underwent comprehensive two-dimensional Doppler echocardiography with three-dimensional speckle-tracking echocardiography (3DSTE). Results: Thicker interventricular septum, increased left ventricular ejection fraction and impaired early and late transmitral flow velocities could be detected in healthy pregnant subjects as compared to those of non-pregnant individuals. End-systolic maximum LA volume was increased with elevated stroke volume and emptying fraction. While early diastolic LA volume was preserved with elevated stroke volume and emptying fraction, late diastolic LA volume, stroke volume and emptying fraction remained unchanged. However, indexed LA volumes did not differ between the groups. Among end-systolic peak global LA strains, only LA longitudinal strain (LS) was increased, while all others remained unchanged. Among regional strains, basal, midatrial and superior LA circumferential strain (CS) and LA-LS were increased except for basal LA-CS, which was impaired. Among late diastolic LA strains at atrial contraction, none of them showed any significant changes in healthy pregnant subjects compared with those of non-pregnant women. Conclusions: With a detailed 3DSTE study, elevated end-systolic LA volume and preserved diastolic LA volumes, together with enhanced end-systolic LA reservoir and early diastolic LA conduit functional properties, could be detected with features of preserved late diastolic booster pump function in healthy women during mid-term pregnancy (second trimester). When comparing indexed LA volumes, no significant difference could be confirmed between the pregnant and non-pregnant groups. This suggests that the increased end-systolic LA volume may be an adaptation to increased body weight.