Volume 18 Supplement 1
Left Ventricular torsion rates by CMR correlate with invasively-derived hemodynamic data in pediatric pulmonary hypertension
© Dufva et al. 2016
Published: 27 January 2016
Pulmonary hypertension (PH) is a progressive disease that results in right ventricular dysfunction through increased resistive afterload and pulmonary arterial (PA) stiffening. The ventricles are connected at the inter-ventricular sulcus, share an interlaced network of muscle fibers, and are hemodynamically dependent upon each other via the interventricular septum (IVS). Thus, the left ventricle (LV) plays a major role in RV contractile performance and may also be affected in this disease via ventricular-ventricular interaction. The relationship between hemodynamic parameters and torsion rate is unknown. We hypothesized that LV torsion rate is reduced in pediatric PH and is concomitant with hemodynamic markers of PH, and that this is due to the impact of prolonged increased impedance, resulting in reduced RV performance.
Tagged cine CMR images were acquired for 8 pediatric PH patients and 18 control-matched subjects. LV systolic torsion rate (TR) was quantified using harmonic phase analysis. Right heart catheterization and echocardiography was performed on PH patients. Vascular ventricular coupling (VVC) was estimated with the single beat pressure-volume method and calculated as the ratio of arterial elastance to ventricular end systolic elastance (contractility).
LV TR was significantly reduced in PH patients compared to control patients (TR=1.61 ± 0.890/systolic cycle versus 3.04 ± 1.480/systolic cycle, p = 0.0189). LV TR correlated highly with mean pulmonary arterial pressure (mPAP, r = 0.93, p = 0.0008), RV systolic pressure (r = 0.94, p = 0.0005), and pulmonary vascular resistance (PVR, r = 0.93, p = 0.0010). VVC correlated highly with LV TR (r = 0.85, p = 0.0071), as did RV contractility (r = 0.86, p = 0.0063).
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.