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Am J Physiol Heart Circ Physiol. 2019 Aug 1;317(2):H300-H307. doi: 10.1152/ajpheart.00694.2018. Epub 2019 Apr 12.

Left ventricular and proximal aorta coupling in magnetic resonance imaging: aging together?

Author information

1
Laboratoire d'Imagerie Biomédicale, Sorbonne Universités, Université Pierre et Marie Curie-Paris 6, Institut National de la Santé et de la Recherche Médicale 1146, Centre National de la Recherche Scientifique 7371, Paris , France.
2
Department of Cardiovascular and Thoracic Imaging and Interventional Radiology, Institute of Cardiology, Hôpital Pitié-Salpêtrière, Paris , France.
3
Institute of Cardiometabolism and Nutrition , Paris , France.
4
Division of Cardiology, Taipei Veterans General Hospital and National Yang-Ming University , Taipei , Taiwan.
5
Department of Cardiology, Oslo University Hospital , Oslo , Norway.
6
University of Paris Descartes, Georges-Pompidou European Hospital Assistance Publique-Hôpitaux de Paris, and Institut National de la Santé et de la Recherche Médicale U970 , Paris , France.
7
Department of Radiology, University of Wisconsin School of Medicine and Public Health , Madison, Wisconsin.
8
Cardiovascular Imaging, Division of Cardiology, Johns Hopkins University, Baltimore, Maryland.

Abstract

The importance of aorta-ventricular coupling in cardiovascular disease is recognized but underestimated. The contribution of the age-related decline in ascending aortic function compared with characteristic impedance and total peripheral resistance on left ventricular function and remodeling is poorly studied. Our aim was to evaluate the relation of proximal aortic distensibility and impedance with left ventricular geometry and function in asymptomatic individuals. We prospectively studied 100 subjects (47 men, 53 women, age: 20-84 yr). Aortic strain, distensibility, arch pulse wave velocity, characteristic impedance (Zc), total peripheral resistance, left ventricular (LV) volumes and mass, wall stress, and peak global circumferential myocardial strain and strain rates were determined by MRI. Central pressures were measured from tonometry. Ea/Ev, an index of vascular-ventricular coupling, and LV wall stress were preserved across age- or aortic-stiffness-stratified groups. Static and pulsatile components of aortic load were differentially associated with age. Increased total vascular resistance was associated with decreased LV strain and increased concentric remodeling [ratio of LV mass to end-diastolic volume (M/V ratio)] in all individuals. In younger individuals (<45 yr), aortic distensibility was related to LV strain and concentric remodeling (M/V ratio), whereas Zc was related to LV strain and concentric remodeling (M/V ratio) in older individuals (>45 yr). Early age-related stiffening of the ascending aorta is a component of LV afterload subsequently associated with increased aortic impedance and alterations in LV geometry, namely concentric remodeling, decreased myocardial strain, and increased stroke work such that LV wall stress and arterial-ventricular coupling are preserved. NEW & NOTEWORTHY Local flow and deformation can both be assessed with high precision noninvasively in the ascending aorta using MRI. Combined with central pressure measurement, they provide distensibility and impedance and simultaneous reference assessment of left ventricular deformation and geometry, hence a comprehensive evaluation of arterial-ventricular coupling to study physiology and disease.

KEYWORDS:

aging; aortic stiffness; cardiac magnetic resonance; impedance; left ventricular function; vascular-ventricular coupling

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