Treating a 20 mm Hg gradient alleviates myocardial hypertrophy in experimental aortic coarctation.
J Surg Res
; 218: 194-201, 2017 10.
Article
in En
| MEDLINE
| ID: mdl-28985849
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 ANDMETHODS:
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.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Aortic Coarctation
/
Hypertrophy, Left Ventricular
Type of study:
Diagnostic_studies
/
Etiology_studies
/
Evaluation_studies
/
Guideline
/
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
J Surg Res
Year:
2017
Type:
Article