Changes in overall ventricular myocardial architecture in the setting of a porcine animal model of right ventricular dilation

Journal of Cardiovascular Magnetic Resonance

Research

Jesper R. Frandsen¹  Michael Pedersen²  Christine Ilkjær³  Vibeke Hjortdal³  Peter Agger³  Morten Smerup⁴  John B. Partridge⁵  Robert H. Anderson⁶  Christoffer Laustsen⁷  Steffen Ringgaard⁷ 

[1] Center for Functionally Integrative Neuroscience, Aarhus University Hospital, Aarhus, Denmark;Comparative Medicine Lab, Aarhus University Hospital, Aarhus, Denmark;Department of Clinical Medicine, Aarhus University, Aarhus, Denmark;Department of Cardiothoracic & Vascular Surgery, Aarhus University Hospital, Skejby, Aarhus, Denmark;Department of Clinical Medicine, Aarhus University, Aarhus, Denmark;Department of Cardiothoracic Surgery, Rigshospitalet, Copenhagen, Denmark;Eurobodalla Unit, Rural Clinical School of the ANU College of Medicine, Biology & Environment, Batemans Bay, NSW, Australia;Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK;MR Research Center, Aarhus University Hospital, Aarhus, Denmark;Department of Clinical Medicine, Aarhus University, Aarhus, Denmark;

关键词: Myocardial remodeling;    Diffusion tensor imaging;    Heart failure;    Congenital heart disease;   

DOI  :  10.1186/s12968-017-0404-0

 received in 2017-04-06, accepted in 2017-10-18,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundChronic pulmonary regurgitation often leads to myocardial dysfunction and heart failure. It is not fully known why secondary hypertrophy cannot fully protect against the increase in wall stress brought about by the increased end-diastolic volume in ventricular dilation. It has been assumed that mural architecture is not deranged in this situation, but we hypothesised that there might be a change in the pattern of orientation of the aggregations of cardiomyocytes, which would contribute to contractile impairment.MethodsWe created pulmonary valvular regurgitation by open chest, surgical suturing of its leaflets in seven piglets, performing sham operations in seven control animals. Using cardiovascular magnetic resonance imaging after 12 weeks of recovery, we demonstrated significantly increased right ventricular volumes in the test group. After sacrifice, diffusion tensor imaging of their hearts permitted measurement of the orientation of the cardiomyocytes.ResultsThe helical angles in the right ventricle approached a more circumferential orientation in the setting of right ventricular RV dilation (p = 0.007), with an increased proportion of surface-parallel cardiomyocytes. In contrast, this proportion decreased in the left ventricle. Also in the left ventricle a higher proportion of E3 angles with a value around zero was found, and conversely a lower proportion of angles was found with a numerical higher value. In the dilated right ventricle the proportion of E3 angles around −90° is increased, while the proportion around 90° is decreased.ConclusionContrary to traditional views, there is a change in the orientation of both the left ventricular and right ventricular cardiomyocytes subsequent to right ventricular dilation. This will change their direction of contraction and hinder the achievement of normalisation of cardiomyocytic strain, affecting overall contractility. We suggest that the aetiology of the cardiac failure induced by right vetricular dilation may be partly explained by morphological changes in the myocardium itself.

【 授权许可】

CC BY   
© The Author(s). 2017