Right ventricular regional wall curvedness and area strain in patients with repaired tetralogy of Fallot

Abstract

Tan RS, Kassab G. Right ventricular regional wall curvedness and area strain in patients with repaired tetralogy of Fallot. Am J Physiol Heart Circ Physiol 302: H1306 -H1316, 2012. First published December 30, 2011 doi:10.1152/ajpheart.00679.2011.-A quantitative understanding of right ventricular (RV) remodeling in repaired tetralogy of Fallot (rTOF) is crucial for patient management. The objective of this study is to quantify the regional curvatures and area strain based on three-dimensional (3-D) reconstructions of the RV using cardiac magnetic resonance imaging (MRI). Fourteen (14) rTOF patients and nine (9) normal subjects underwent cardiac MRI scan. 3-D RV endocardial surface models were reconstructed from manually delineated contours and correspondence between end-diastole (ED) and end systole (ES) was determined. Regional curvedness (C) and surface area at ED and ES were calculated as well as the area strain. The RV shape and deformation in rTOF patients differed from normal subjects in several respects. Firstly, the curvedness at ED (mean for 13 segments, 0.030 Ϯ 0.0076 vs. 0.029 Ϯ 0.0065 mm Ϫ1 ; P Ͻ 0.05) and ES (mean for 13 segments, 0.040 Ϯ 0.012 vs. 0.034 Ϯ 0.0072 mm Ϫ1 ; P Ͻ 0.001) was decreased by chronic pulmonary regurgitation. Secondly, the surface area increased significantly at ED (mean for 13 segments, 982 Ϯ 192 vs. 1,397 Ϯ 387 mm 2 ; P Ͻ 0.001) and ES (mean for 13 segments, 576 Ϯ 130 vs. 1,012 Ϯ 302 mm 2 ; P Ͻ 0.001). In particular, rTOF patients had significantly larger surface area than that in normal subjects in the free wall but not for the septal wall. Thirdly, area strain was significantly decreased (mean for 13 segments, 56 Ϯ 6 vs. 34 Ϯ 7%; P Ͻ 0.0001) in rTOF patients. Fourthly, there were increases in surface area at ED (5,726 Ϯ 969 vs. 6,605 Ϯ 1,122 mm 2 ; P Ͻ 0.05) and ES (4,280 Ϯ 758 vs. 5,569 Ϯ 1,112 mm 2 ; P Ͻ 0.01) and decrease in area strain (29 Ϯ 8 vs. 18 Ϯ 8%; P Ͻ 0.001) for RV outflow tract. These findings suggest significant geometric and strain differences between rTOF and normal subjects that may help guide therapeutic treatment. magnetic resonance imaging; curvature; right ventricular remodeling; deformation; three-dimensional reconstruction TETRALOGY OF FALLOT (TOF) is the most common cyanotic congenital heart disease (19). The main features include ventricular septum defect, subpulmonary stenosis, and overriding aorta and right ventricular (RV) hypertrophy. Surgical repair is usually performed in early infancy to widen the passage from the RV to the pulmonary artery and close the ventricular septal defect. This ensures separation of oxygen-rich and oxygenpoor blood flows to the proper chambers. Surgical repair of TOF often involves disruption of pulmonary valve integrity that leads to pulmonary regurgitation (PR; Refs. 8, 37). This in turn causes RV dilation (9, 23) and RV outflow tract (RVOT) aneurysm (2-3, 13, 28 -29). The RV dilation is usually tolerated with little or no symptoms during the first two to three decades of age. If left untreated, however, continued...

Ventricular kinetic energy may provide a novel noninvasive way to assess ventricular performance in patients with repaired tetralogy of Fallot

“…31 Ventricular strain, or local myocardial deformation, evaluated by cardiac magnetic resonance and echocardiography speckle-tracking may be an earlier predictor of regional ventricular dysfunction compared to ejection fraction in patients with rTOF. 3,5,26 Whether microscopic myocardial changes or changes in KE and altered hemodynamics provide better indicators for declining ventricular function warrant further investigation.…”

“…Surgical correction of Tetralogy of Fallot typically involves ventricular septal defect closure, relief of right ventricular outflow tract obstruction, disruption of the pulmonary valve that results in pulmonary regurgitation, and placement of an outflow patch. 3 Expected postoperative pulmonary regurgitation has been associated with progressive right ventricular dilatation and ventricular dysfunction. 4 Alterations in hemodynamics that frequently occur after repair ultimately contribute to poor long-term outcomes, including progressive exercise intolerance, ventricular arrhythmia, and sudden cardiac death.…”

Fresh Autologous Pericardium to Reconstruct the Pulmonary Valve at the Annulus When Tetralogy of Fallot Requires a Transannular Patch at Midterm

“…18 Despite these observations, maximum harm to the RV is induced by PI. 19,20 The procedure discussed in this study helps in creating a new pulmonary annulus and a competent valve for that size annulus by creating an anterior leaflet of the PV that coapts with the native leaflets. In comparing the results of this procedure with results wherein a TAP was not needed and the native valve was preserved, we observed that this correction performs in a manner similar to the correction in our No-TAP group, with regard to the development and progression of PI.…”

Regional Differences in End-Diastolic Volumes between 3D Echo and CMR in HLHS Patients

“…There is little literature on regional analysis of the right ventricle (RV) in Fontan patients like those with hypoplastic left heart syndrome (HLHS). For repaired Tetralogy of Fallot (ToF) patients, Zhong et al (8) proposed a 15-segment subdivision.…”

“…Inspired by the divisions carried out by Menon et al, Zhong et al, and Wong et al (8–10), and taking into account the standard AHA 17 segment division for the LV proposed in Ref. (11), in this paper, we propose to divide the 3D RV shape into 14 segments as indicated in Figure 3.…”