Faculty Collaboration Database

Treating a 20 mm Hg gradient alleviates myocardial hypertrophy in experimental aortic coarctation. J Surg Res 2017 Oct;218:194-201

Date

10/08/2017

Pubmed ID

28985849

Pubmed Central ID

PMC5679105

DOI

10.1016/j.jss.2017.05.053

Scopus ID

2-s2.0-85020927176 (requires institutional sign-in at Scopus site)   7 Citations

Abstract

BACKGROUND: Children with coarctation of the aorta (CoA) can have a hyperdynamic and remodeled left ventricle (LV) from increased afterload. Literature from an experimental model suggests the putative 20 mm Hg blood pressure gradient (BPG) treatment guideline frequently implemented in CoA studies may permit irreversible vascular changes. LV remodeling from pressure overload has been studied, but data are limited following correction and using a clinically representative BPG.

MATERIALS AND METHODS: Rabbits underwent CoA at 10 weeks to induce a 20 mm Hg BPG using permanent or dissolvable suture thereby replicating untreated and corrected CoA, respectively. Cardiac function was evaluated at 32 weeks by magnetic resonance imaging using a spoiled cine GRE sequence (TR/TE/FA 8/2.9/20), 14 × 14-cm FOV, and 3-mm slice thickness. Images (20 frames/cycle) were acquired in 6-8 short axis views from the apex to the mitral valve annulus. LV volume, ejection fraction (EF), and mass were quantified.

RESULTS: LV mass was elevated for CoA (5.2 ± 0.55 g) versus control (3.6 ± 0.16 g) and corrected (4.0 ± 0.44 g) rabbits, resulting in increased LV mass/volume ratio for CoA rabbits. A trend toward increased EF and stroke volume was observed but did not reach significance. Elevated EF by volumetric analysis in CoA rabbits was supported by concomitant increases in total aortic flow by phase-contrast magnetic resonance imaging.

CONCLUSIONS: The indices quantified trended toward a persistent hyperdynamic LV despite correction, but differences were not statistically significant versus control rabbits. These findings suggest the current putative 20 mm Hg BPG for treatment may be reasonable from the LV's perspective.

Author List

Wendell DC, Friehs I, Samyn MM, Harmann LM, LaDisa JF Jr

Authors

John F. LaDisa PhD Professor in the Pediatrics department at Medical College of Wisconsin
Margaret Mary Samyn MD Professor in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Aortic Coarctation
Disease Models, Animal
Hypertrophy, Left Ventricular
Magnetic Resonance Imaging
Male
Rabbits
Random Allocation
Ultrasonography