Moving beyond size: vorticity and energy loss are correlated with right ventricular dysfunction and exercise intolerance in repaired Tetralogy of Fallot

Abstract Background The global effect of chronic pulmonary regurgitation (PR) on right ventricular (RV) dilation and dysfunction in repaired Tetralogy of Fallot (rTOF) patients is well studied by cardiovascular magnetic resonance (CMR). However, the links between PR in the RV outflow tract (RVOT), RV dysfunction and exercise intolerance are not clarified by conventional measurements. Not all patients with RV dilation share the same intracardiac flow characteristics, now measurable by time resolved three-dimensional phase contrast imaging (4D flow). In our study, we quantified regional vorticity and energy loss in rTOF patients and correlated these parameters with RV dysfunction and exercise capacity. Methods rTOF patients with 4D flow datasets were retrospectively analyzed, including those with transannular/infundibular repair and conduit repair. Normal controls and RV dilation patients with atrial-level shunts (Qp:Qs > 1.2:1) were included for comparison. 4D flow was post-processed using IT Flow (Cardioflow, Japan). Systolic/diastolic vorticity (ω, 1/s) and viscous energy loss (VEL, mW) in the RVOT and RV inflow were measured. To characterize the relative influence of diastolic vorticity in the two regions, an RV Diastolic Vorticity Quotient (ωRVOT-Diastole/ωRV Inflow-Diastole, RV-DVQ) was calculated. Additionally, RVOT Vorticity Quotient (ωRVOT-Diastole/ωRVOT-Systole, RVOT-VQ) and RVOT Energy Quotient (VELRVOT-Diastole/VELRVOT-Systole, RVOT-EQ) was calculated. In rTOF, measurements were correlated against conventional CMR and exercise stress test results. Results 58 rTOF patients, 28 RV dilation patients and 12 controls were included. RV-DVQ, RVOT-VQ, and RVOT-EQ were highest in rTOF patients with severe PR compared to rTOF patients with non-severe PR, RV dilation and controls (p < 0.001). RV-DVQ positively correlated with RV end-diastolic volume (0.683, p < 0.001), PR fraction (0.774, p < 0.001) and negatively with RV ejection fraction (− 0.521, p = 0.003). Both RVOT-VQ, RVOT-EQ negatively correlated with VO2-max (− 0.587, p = 0.008 and − 0.617, p = 0.005) and % predicted VO2-max (− 0.678, p = 0.016 and − 0.690, p = 0.001). Conclusions In rTOF patients, vorticity and energy loss dominate the RVOT compared to tricuspid inflow, correlating with RV dysfunction and exercise intolerance. These 4D flow-based measurements may be sensitive biomarkers to guide surgical management of rTOF patients.

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Quantifying Pulmonary Regurgitation and Right Ventricular Function in Surgically Repaired Tetralogy of Fallot

Circulation Cardiovascular Imaging ◽

10.1161/circimaging.112.972588 ◽

2012 ◽

Vol 5 (5) ◽

pp. 637-643 ◽

Cited By ~ 71

Author(s):

Laura Mercer-Rosa ◽

Wei Yang ◽

Shelby Kutty ◽

Jack Rychik ◽

Mark Fogel ◽

...

Keyword(s):

Right Ventricular ◽

Ventricular Function ◽

Tetralogy Of Fallot ◽

Right Ventricular Function ◽

Pulmonary Regurgitation ◽

Repaired Tetralogy Of Fallot

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Altered biventricular hemodynamic forces in patients with repaired tetralogy of Fallot and right ventricular volume overload because of pulmonary regurgitation

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00330.2018 ◽

2018 ◽

Vol 315 (6) ◽

pp. H1691-H1702 ◽

Cited By ~ 5

Author(s):

Pia Sjöberg ◽

Johannes Töger ◽

Erik Hedström ◽

Per Arvidsson ◽

Einar Heiberg ◽

...

Keyword(s):

Blood Flow ◽

Right Ventricular ◽

Tetralogy Of Fallot ◽

Flow Direction ◽

Pulmonary Regurgitation ◽

Ventricular Volume ◽

Left Ventricular ◽

Hemodynamic Forces ◽

Control Subjects ◽

Repaired Tetralogy Of Fallot

Intracardiac hemodynamic forces have been proposed to influence remodeling and be a marker of ventricular dysfunction. We aimed to quantify the hemodynamic forces in patients with repaired tetralogy of Fallot (rToF) to further understand the pathophysiological mechanisms as this could be a potential marker for pulmonary valve replacement (PVR) in these patients. Patients with rToF and pulmonary regurgitation (PR) > 20% ( n = 18) and healthy control subjects ( n = 15) underwent MRI, including four-dimensional flow. A subset of patients ( n = 8) underwent PVR and MRI after surgery. Time-resolved hemodynamic forces were quantified using 4D-flow data and indexed to ventricular volume. Patients had higher systolic and diastolic left ventricular (LV) hemodynamic forces compared with control subjects in the lateral-septal/LV outflow tract ( P = 0.011 and P = 0.0031) and inferior-anterior ( P < 0.0001 and P < 0.0001) directions, which are forces not aligned with blood flow. Forces did not change after PVR. Patients had higher RV diastolic forces compared with control subjects in the diaphragm-right ventricular (RV) outflow tract (RVOT; P < 0.001) and apical-basal ( P = 0.0017) directions. After PVR, RV systolic forces in the diaphragm-RVOT direction decreased ( P = 0.039) to lower levels than in control subjects ( P = 0.0064). RV diastolic forces decreased in all directions ( P = 0.0078, P = 0.0078, and P = 0.039) but were still higher than in control subjects in the diaphragm-RVOT direction ( P = 0.046). In conclusion, patients with rToF and PR had LV hemodynamic forces less aligned with intraventricular blood flow compared with control subjects and higher diastolic RV forces along the regurgitant flow direction in the RVOT and that of tricuspid inflow. Remaining force differences in the LV and RV after PVR suggest that biventricular pumping does not normalize after surgery. NEW & NOTEWORTHY Biventricular hemodynamic forces in patients with repaired tetralogy of Fallot and pulmonary regurgitation were quantified for the first time. Left ventricular hemodynamic forces were less aligned to the main blood flow direction in patients compared with control subjects. Higher right ventricular forces were seen along the pulmonary regurgitant and tricuspid inflow directions. Differences in forces versus control subjects remain after pulmonary valve replacement, suggesting that altered biventricular pumping does not normalize after surgery.

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Ratio of Early Diastolic Tricuspid Inflow to Tricuspid Lateral Annulus Velocity Reflects Pulmonary Regurgitation Severity but Not Right Ventricular Diastolic Function in Children With Repaired Tetralogy of Fallot

Pediatric Cardiology ◽

10.1007/s00246-012-0612-1 ◽

2012 ◽

Vol 34 (5) ◽

pp. 1112-1117 ◽

Cited By ~ 5

Author(s):

Yasunobu Hayabuchi ◽

Miho Sakata ◽

Tatsuya Ohnishi ◽

Miki Inoue ◽

Shoji Kagami

Keyword(s):

Right Ventricular ◽

Diastolic Function ◽

Tetralogy Of Fallot ◽

Pulmonary Regurgitation ◽

Ventricular Diastolic Function ◽

Repaired Tetralogy Of Fallot ◽

Right Ventricular Diastolic Function

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Right ventricular systolic dysfunction but not dilatation correlates with prognostically significant reductions in exercise capacity in repaired Tetralogy of Fallot

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jez245 ◽

2019 ◽

Vol 21 (8) ◽

pp. 906-913 ◽

Cited By ~ 1

Author(s):

Imran Rashid ◽

Adil Mahmood ◽

Tevfik F Ismail ◽

Shamus O’Meagher ◽

Shelby Kutty ◽

...

Keyword(s):

Right Ventricular ◽

Tetralogy Of Fallot ◽

Exercise Capacity ◽

Multivariable Analysis ◽

Cardiopulmonary Exercise Testing ◽

Pulmonary Regurgitation ◽

Left Ventricular ◽

Left Ventricular Ejection ◽

Peak Vo2 ◽

Repaired Tetralogy Of Fallot

Abstract Aims The optimal timing for pulmonary valve replacement in asymptomatic patients with repaired Tetralogy of Fallot (rTOF) and pulmonary regurgitation remains uncertain but is often guided by increases in right ventricular (RV) end-diastolic volume. As cardiopulmonary exercise testing (CPET) performance is a strong prognostic indicator, we assessed which cardiovascular magnetic resonance (CMR) parameters correlate with reductions in exercise capacity to potentially improve identification of high-risk patients. Methods and results In all, 163 patients with rTOF (mean age 24.5 ± 10.2 years) who had previously undergone CMR and standardized CPET protocols were included. The indexed right and left ventricular end-diastolic volumes (RVEDVi, LVEDVi), right and left ventricular ejection fractions (RVEF, LVEF), indexed RV stroke volume (RVSVi), and pulmonary regurgitant fraction (PRF) were quantified by CMR and correlated with CPET-determined peak oxygen consumption (VO2) or peak work. On univariable analysis, there was no significant correlation between RVEDVi and PRF with peak VO2 or peak work (% Jones-predicted). In contrast, RVEF and RVSVi had significant correlations with both peak VO2 and peak work that remained significant on multivariable analysis. For a previously established prognostic peak VO2 threshold of <27 mL/kg/min, receiver-operating characteristic curve analysis demonstrated a Harrell’s c of 0.70 for RVEF (95% confidence interval 0.61–0.79) with a sensitivity of 88% for RVEF <40%. Conclusion In rTOF, CMR indices of RV systolic function are better predictors of CPET performance than RV size. An RVEF <40% may be useful to identify prognostically significant reductions in exercise capacity in patients with varying degrees of RV dilatation.

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