Author: Geoffrey D. Clarke, Laura A. Cox, Alexander J Moody, Peter W Nathanielsz, Bowen Yang 👨🔬
Affiliation: Wake Forest University School of Medicine, University of Texas Health Science Center at San Antonio, Texas Biomedical Research Institute 🌍
Purpose:
Recent studies show diagnostic value of myocardial strain analysis for left ventricular (LV) function using cardiac magnetic resonance imaging (CMR). RV function analysis is more challenging due to the complex geometry, thinner walls, more prominent trabeculations, and imaging artifacts. We performed CMR feature tracking (CMR-FT) for RV strain measurements in offspring of pregnant baboons exposed to moderate maternal undernutrition (MUN).
Methods:
Controls (CTL) mothers were fed ad libitum, while MUN mothers received 70% of weight-adjusted controls intake from pregnancy diagnosis through lactation. CMR (3T Siemens TIM Trio) was performed using a bSSFP sequence with retrospective gating. Cine images of four-chamber (4CV) and short-axis (SAX) views of RV were acquired. Functional analyses were conducted using the cvi42® software. Global radial (GRS), circumferential (GCS), and longitudinal strain (GLS) parameters were calculated from 3D models. Data were analyzed using R statistical software.
Results:
Young, 5.5±1.3 years, (~25 human yrs), MUN baboons (6M/7F) showed RV impairments versus CTL (6M/7F), including reduced ejection fraction (M: 52.3±4.3 vs. 34.6±9.6%, F: 52.0±6.6 vs. 37.9±8.8%, p≤0.01), stroke volume/body surface area (M: 29.4±7.7 vs. 18.9±6.4, F: 22.1±5.4 vs. 13.2±4.8 mL/m², p≤0.05), cardiac output (M: 1.59±0.67 vs. 1.03±0.28 L/min, p≤0.01), GRS (M: 25.8±5.5 vs. 13.8±8.2%, F: 21.8±7.1 vs. 13.6±4.9%, p≤0.01), GCS (M: -15.9±2.4 vs. -9.8±4.1%, F: -13.9±2.8 vs. -9.7±2.9%, p≤0.01), and global radial systolic velocity (GRSV) (M: 40.3±11.0 vs. 18.8±8.3 mm/s, F: 34.5±14.4 vs. 20.5±7.0, p≤0.05). Middle age, 13.9±1.4 years, (~65 human yrs), no significant group differences were observed in MUN vs CTL volumes, though MUN females had lower GRSV (57.6±15.6 vs. 30.4±14.1 mm/s, p=0.02).
Conclusion:
We conclude: MUN offspring experience early RV impairment, which later normalizes with post-weaning dietary recovery. MUN causes sexually dimorphic early RV dysfunction normalized by middle age, highlighting the feasibility of CMR-FT for longitudinal RV analysis and the significance of life-course cardiovascular research.