Exercise-induced irregular right heart flow dynamics in adolescents and young adults born preterm

Jacob A Macdonald,Kristin Haraldsdottir,Grant S Roberts,Oliver Wieben,Christopher J Francois,Philip A Corrado,Kara N Goss,Marlowe W Eldridge,Gregory P Barton,Arij G Beshish

doi:10.1186/s12968-021-00816-2

Jacob A Macdonald, Kristin Haraldsdottir + Show 8 more

Open Access

https://doi.org/10.1186/s12968-021-00816-2

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Abstract

BackgroundPreterm birth has been linked to an elevated risk of heart failure and cardiopulmonary disease later in life. With improved neonatal care and survival, most infants born preterm are now reaching adulthood. In this study, we used 4D flow cardiovascular magnetic resonance (CMR) coupled with an exercise challenge to assess the impact of preterm birth on right heart flow dynamics in otherwise healthy adolescents and young adults who were born preterm.MethodsEleven young adults and 17 adolescents born preterm (< 32 weeks of gestation and < 1500 g birth weight) were compared to 11 young adult and 18 adolescent age-matched controls born at term. Stroke volume, cardiac output, and flow in the main pulmonary artery were quantified with 4D flow CMR. Kinetic energy and vorticity were measured in the right ventricle. All parameters were measured at rest and during exercise at a power corresponding to 70% VO2max for each subject. Multivariate linear regression was used to perform age-adjusted term-preterm comparisons.ResultsWith exercise, stroke volume increased 10 ± 21% in term controls and decreased 4 ± 18% in preterm born subjects (p = 0.007). This resulted in significantly reduced capacity to increase cardiac output in response to exercise stress for the preterm group (58 ± 26% increase in controls, 36 ± 27% increase in preterm, p = 0.004). Elevated kinetic energy (KEterm = 71 ± 22 nJ, KEpreterm = 87 ± 38 nJ, p = 0.03) and vorticity (ωterm = 79 ± 16 s−1, ωpreterm = 94 ± 32 s−1, p = 0.01) during diastole in the right ventricle (RV) suggested altered RV flow dynamics in the preterm subjects. Streamline visualizations showed altered structure to the diastolic filling vortices in those born preterm.ConclusionsFor the participants examined here, preterm birth appeared to result in altered right-heart flow dynamics as early as adolescence, especially during diastole. Future studies should evaluate whether the altered dynamics identified here evolves into cardiopulmonary disease later in life.Trial registration None

Highlights

Preterm birth has been linked to an elevated risk of heart failure and cardiopulmonary disease later in life
Cardiovascular magnetic resonance (CMR) studies demonstrate that healthy adults born preterm have smaller right ventricular (RV) volumes when compared to term controls [10, 11], which may further contribute to exercise limitations in this population
One term child and one preterm child stopped exercising during imaging due to trouble concentrating for the entire scanning session

Summary

Introduction

Preterm birth has been linked to an elevated risk of heart failure and cardiopulmonary disease later in life. Two recent studies have shown evidence of early right ventricular (RV)-pulmonary vascular uncoupling, a decreased ability of the RV to increase contractility or maintain stroke volume to preserve flow in the face of increased pulmonary arterial afterload, due to underlying preclinical pulmonary hypertension in adults born extremely preterm [4, 7]. This may be due in part to altered pulmonary microvascular structure and function as a result of underdeveloped cardiopulmonary systems at birth in the preterm neonate [8]. Cardiovascular magnetic resonance (CMR) studies demonstrate that healthy adults born preterm have smaller RV volumes when compared to term controls [10, 11], which may further contribute to exercise limitations in this population

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