Cardiac Magnetic Resonance Imaging Correlates of Exercise Capacity in Patients With Surgically Repaired Tetralogy of Fallot

doi:10.1016/j.amjcard.2007.06.038

The American Journal of Cardiology

Volume 100, Issue 9, 1 November 2007, Pages 1446-1450

https://doi.org/10.1016/j.amjcard.2007.06.038 Get rights and content

Objective exercise testing in patients with repaired tetralogy of Fallot frequently identifies gross deficiencies in exercise capacity. These findings are typically attributed to right ventricular dysfunction, pulmonary valve regurgitation, and pulmonary artery stenosis and are used to justify referrals for surgical or transcatheter interventions. However, the relation between right-sided cardiac abnormalities and exercise capacity in this patient group is poorly understood. Cardiac magnetic resonance imaging correlates of exercise capacity in 37 patients with repaired TOF were retrospectively examined. In conclusion, on multivariate analysis, right ventricular ejection fraction was the only cardiac magnetic resonance imaging predictor of percentage of predicted peak oxygen consumption, oxygen consumption at ventilatory anaerobic threshold, and oxygen pulse.

Section snippets

Methods

Departmental and institutional review boards approved this study protocol. CMRI and exercise data for all patients with TOF who underwent CMRI and exercise testing within 1 year of each other from January 2003 to January 2006 were reviewed retrospectively. Patients with intervening surgical or transcatheter interventions were excluded. Relevant clinical data, including age, gender, date, and age at each surgical procedure, type of surgery, medications, and clinical status, were obtained from

Results

Thirty-seven patients (age 26.8 ± 11.9 years) met inclusion criteria. Demographic characteristics are listed in Table 1. All patients were in New York Heart Association classification I or II, and the prevalence of significant cardiovascular signs and symptoms was relatively low.

CMRI characteristics of the patient population are listed in Table 2 and Figure 1. Mean LV ejection fraction was 60 ± 5.8%. It was less than normal (<55%) in only 6 patients (16%) and <40% in no patient. Mean RV

Discussion

In this cohort of patients with repaired TOF, RV systolic function, measured using RV ejection fraction, on multivariate analysis was the only independent CMRI correlate of percentage of predicted peak VO₂, oxygen pulse, and ventilatory anaerobic threshold. On multivariate analysis, there was no correlation with LV systolic function, pulmonary regurgitation fraction, or RV size.

The lack of correlation of LV systolic function with exercise parameters in this study may be because few of our

References (19)

B. Eyskens et al.
Homograft insertion for pulmonary regurgitation after repair of tetralogy of Fallot improves cardiorespiratory exercise performance
Am J Cardiol
(2000)
H. Jonsson et al.
Pulmonary function thirteen to twenty-six years after repair of tetralogy of Fallot
J Thorac Cardiovasc Surg
(1994)
M. Ercisli et al.
Does delayed correction interfere with pulmonary functions and exercise tolerance in patients with tetralogy of Fallot?
Chest
(2005)
H. Ishii et al.
Usefulness of exercise-induced changes in plasma levels of brain natriuretic peptide in predicting right ventricular contractile reserve after repair of tetralogy of Fallot
Am J Cardiol
(2005)
J. van den Berg et al.
Clinical condition at mid-to-late follow-up after transatrial-transpulmonary repair of tetralogy of Fallot
J Thorac Cardiovasc Surg
(2007)
G.K. Singh et al.
Right ventricular function and exercise performance late after primary repair of tetralogy of Fallot with the transannular patch in infancy
Am J Cardiol
(1998)
A. Giardini et al.
Impact of pulmonary regurgitation and right ventricular dysfunction on oxygen uptake recovery kinetics in repaired tetralogy of Fallot
Eur J Heart Fail
(2006)
A.L. Clark et al.
Ventilatory responses to exercise in adults after repair of tetralogy of Fallot
Br Heart J
(1995)
P.J. Horneffer et al.
Long-term results of total repair of tetralogy of Fallot in childhood
Ann Thorac Surg
(1990)

There are more references available in the full text version of this article.

Cited by (56)

Moving beyond size: vorticity and energy loss are correlated with right ventricular dysfunction and exercise intolerance in repaired Tetralogy of Fallot
2021, Journal of Cardiovascular Magnetic Resonance
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.
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 (ω_{RVOT-Diastole}/ω_{RV Inflow-Diastole,} RV-DVQ) was calculated. Additionally, RVOT Vorticity Quotient (ω_{RVOT-Diastole}/ω_RVOT-Systole, RVOT-VQ) and RVOT Energy Quotient (VEL_{RVOT-Diastole}/VEL_RVOT-Systole, RVOT-EQ) was calculated. In rTOF, measurements were correlated against conventional CMR and exercise stress test 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 VO_2-max (− 0.587, p = 0.008 and − 0.617, p = 0.005) and % predicted VO_2-max (− 0.678, p = 0.016 and − 0.690, p = 0.001).
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.
Physiologic effects and functional outcome after treatment of dysfunctional right ventricular outflow tract in congenital heart disease using a two-stage intervention
2020, International Journal of Cardiology
Citation Excerpt :
Restoration of right ventricular outflow tract (RVOT) function plays a key role of surgical repair in most complex congenital heart diseases. Loss of RVOT function over the course of time [1,2] leading to stenosis (PS) or regurgitation (PR), is associated with exercise intolerance, reduced quality of life, arrhythmias, heart failure and sudden cardiac death [3–6]. Surgical or interventional treatment of RVOT dysfunction is meant to halt these detrimental effects, ideally before functional limitations became irreversible.
Background: Pathophysiological differences in relief of pulmonary stenosis (PS) as opposed to pulmonary regurgitation (PR) by percutaneous pulmonary valve implantation (PPVI) remain elusive, but might impact current assessment of procedural success and ultimately indications.
Methods: Invasive pressure measurements, cardiac magnetic resonance imaging and cardiopulmonary exercise testing were performed before pre-stenting (BMS), after BMS and after PPVI in patients with either PS or PR.
Results: In PS (n = 14), BMS reduced the right ventricular (RV) to systemic pressure ratio (0.8 ± 0.2 vs. 0.4 ± 0.1%; p < .01), improved RF EF (53 ± 14 vs. 59 ± 12%; p = .01) but introduced free PR (PR fraction post 39 ± 12%; p < .01) with no changes in effective RV stroke volume (SV). PPVI eliminated PR (PR fraction 5 ± 3%; p < .01) and improved effective RV SV (p < .01) with no changes in RV EF (p = .47). Peak VO2 improved significantly after BMS, with no changes following PPVI (26 ± 9 vs. 30 ± 11 vs. 31 ± 10 ml/kg*min).
In PR (n = 14), BMS exaggerated PR (PR fraction post 47 ± 10) with reduction in effective RV SV (pre 43 ± 9 vs. post 38 ± 8 ml/m²; p = .01), which improved after PPVI (post PPVI 49 ± 9 ml/m²; p < .01), secondary to elimination of PR (PR fraction 5 ± 4%; p < .01). RV EF (pre 53 ± 11 vs. post 53 ± 9 vs. post PPVI 50 ± 9%) and Peak VO2 (pre 22 ± 7 vs. post 21 ± 7 vs. post PPVI 23 ± 7 ml/kg*min) remained unchanged.
Conclusions: Exercise capacity in patients with right ventricular outflow tract dysfunction is primarily afterload-dependent.
Cardiac performance assessment during cardiopulmonary exercise test can improve the management of children with repaired congenital heart disease
2020, International Journal of Cardiology
Children with repaired congenital heart disease (CHD) have impaired maximal aerobic capacity (VO2max). Determining the causes of their VO2max alteration remains challenging. Cardiac output measure using thoracic impedancemetry during cardiopulmonary exercise tests (CPET) can help to understand the determinants of VO2max in children with open-heart repaired CHD.
We analyzed CPET in 77 children with repaired CHD. Among them, 55 patients had residual lesions. Patients with repaired CHD were compared with 44 age-matched healthy individuals. Maximal oxygen content brought to capillaries (QO2max) and oxygen muscle diffusion capacity (DO2) were assessed using cardiac output measure, Fick principle and simplified Fick law.
In the 55 patients with residual lesion, VO2max, QO2max and DO2 were lower than those of controls (76.1 vs 86% of theoretical value, p < 0.01; 2.15 vs 2.81 L/mn, p < 0.001; 24.7 vs 28.8 ml/min/mmHg, p < 0.05). Decrease in QO2max was due to both impaired stroke volume and chronotropic insufficiency (48 vs 53 ml/m² and p < 0.05; 171 vs 185/min p < 0.001). Patients without residual lesion (22/77) had normal VO2max with lower maximal heart rate compensated by higher SV (p < 0.05).
Aerobic capacity was normal in children without residual lesions after CHD repair. Patients with residual lesion have impaired VO2max due to both lower central and peripheral determinants. Measuring cardiac performance during CPET allowed a better selection of patients with altered cardiac reserve that can benefit from residual lesion treatment and find the good timing for intervention. Detection of peripheral deconditioning can lead to a rehabilitation program.
Effect of ventricular function and volumes on exercise capacity in adults with repaired Tetralogy of Fallot
2018, Indian Heart Journal
Investigate the effects of left and right ventricular function and severity of pulmonary valve regurgitation, quantified by cardiac magnetic resonance (CMR), on exercise tolerance in adult patients who underwent ToF repair at a young age.
This is a retrospective cohort study of 52 patients after ToF surgery and 33 age- and sex-matched healthy volunteers. CMR and cardiopulmonary exercise testing (CPET) were performed on all patients; CPET was performed on control subjects.
The main finding of CPET was a severe decrease in oxygen uptake at peak exercise VO_2peak in TOF patients. The patients were characterized also by lower pulse O_2peak and heart rate at peak exercise. Ejection fraction of the right and left ventricles was correlated (r = 0,32; p = 0,03). Left ventricle ejection fraction was negatively correlated with right ventricular volumes (r = −0,34; p = 0,01) and right ventricular mass (r = −046; p < 0,00). Right ventricular mass was positively correlated with left ventricular variables (left ventricle end diastolic volume, r = 0,43; p = 0,002; left ventricle end systolic volume, r = 0,54; p < 0,00) as was VO_2peak: LVEDV (r = 0,38; p = 0,01); LVESV (r = 0,33; p = 0,03) and LV mass (r = 0,42; p = 0,006).
Exercise intolerance in adults with repaired ToF is markedly depressed. The decreased exercise capacity is correlated with impaired RV function and may be associated also with LV dysfunction, which suggests right-to-left ventricular interaction.
Differential impact of pulmonary regurgitation on patients with surgically repaired pulmonary stenosis versus tetralogy of fallot
2016, American Journal of Cardiology
Citation Excerpt :
Current criteria for PVR in patients with TOF takes into account clinical symptoms and many parameters optimally measured by CMR.12 Ventricular function is a better predictor of clinical status and exercise capacity than RV dilatation in patients with TOF.26,27 Although patients with PS have similar RV dilatation to those with TOF with the same degree of PR, the preservation of RV systolic function may suggest a different natural history, which could alter consideration of timing for PVR.
Patients with repaired pulmonary stenosis (PS) or tetralogy of Fallot (TOF) both develop pulmonary regurgitation (PR) leading to right ventricular (RV) dilatation and dysfunction. We aimed to characterize differential effects of chronic PR in these populations. Patients with surgically repaired PS were matched 1:2 by age and PR fraction with patients with TOF. Patients with previous pulmonary valve replacement were excluded. Cardiovascular magnetic resonance data were compared; peak longitudinal and circumferential systolic strain by feature tracking were compared to evaluate differential contribution of the RV sinus and outflow tract, respectively. PS (n = 24, 41 ± 13 years old) and TOF (n = 47, 39 ± 13 years old) patients did not differ in RV end-diastolic volume (153 ± 45 vs 154 ± 45 ml/m², p = 0.99) or diastolic function. However, patients with PS had preserved RV ejection fraction (54.3 ± 4.4% vs 48.0 ± 7.1%, p <0.0001). Differences were greater in RV circumferential (−15.8 ± 3.3 vs −11.8 ± 3.4, p <0.0001) than longitudinal strain (−18.0 ± 3.8 vs −15.9 ± 3.8, p = 0.04), with particular decrease in the infundibulum (−17.4 ± 7.5 vs −6.8 ± 6.3, p <0.0001). Late gadolinium enhancement in the RV outflow tract was more frequent in patients with TOF (70.2% vs 45.8%, p = 0.001). In conclusion, surgical repair of PS leads to similar RV dilatation and diastolic dysfunction compared to patients with TOF, but differential effects on ventricular systolic function, largely related to differences in the outflow tract. With different patterns of scarring and ventricular remodeling, further study is needed to clarify whether criteria for pulmonary valve replacement in patients with PS should differ from those with TOF.
Mechanisms of maintained exercise capacity in adults with repaired tetralogy of Fallot
2014, International Journal of Cardiology
The mechanisms whereby cardiac output is augmented with exercise in adult repaired tetralogy of Fallot (TOF) are poorly characterised.
16 repaired TOF patients (25 ± 7 years of age) and 8 age and sex matched controls (25 ± 4 years of age) underwent cardiopulmonary exercise testing and then real-time cardiac MRI (1.5 T) at rest and whilst exercising within the scanner, aiming for 30% heart rate reserve (Level 1) and 60% heart rate reserve (Level 2), using a custom-built MRI compatible foot pedal device.
At rest, TOF patients had severely dilated RVs (indexed RV end-diastolic volume: 149 ± 37 mL/m²), moderate-severe PR (regurgitant fraction 35 ± 12%), normal RV fractional area change (FAC) (52 ± 7%) and very mildly impaired exercise capacity (83 ± 15% of predicted maximal work rate). Heart rate and RV FAC increased significantly in TOF patients (75 ± 10 vs 123 ± 17 beats per minute, p < 0.001; 44 ± 7 vs 51 ± 10%, p = 0.025), and similarly in control subjects (70 ± 11 vs 127 ± 12 beats per minute, p < 0.001; 49 ± 7 vs 61 ± 9%, p = 0.003), when rest was compared to Level 2. PR fraction decreased significantly but only modestly, from rest to Level 2 in TOF patients (37 ± 15 to 31 ± 15%, p = 0.002). Pulmonary artery net forward flow was maintained and did not significantly increase from rest to Level 2 in TOF patients (70 ± 19 vs 69 ± 12 mL/beat, p = 0.854) or controls (93 ± 9 vs 95 ± 21 mL/beat, p = 0.648).
During exercise in repaired TOF subjects with dilated RV and free PR, increased total RV output per minute was facilitated by an increase in heart rate, an increase in RV FAC and a decrease in PR fraction.

View all citing articles on Scopus

View full text

Congenital heart diseaseCardiac Magnetic Resonance Imaging Correlates of Exercise Capacity in Patients With Surgically Repaired Tetralogy of Fallot

Section snippets

Methods

Results

Discussion

Am J Cardiol

J Thorac Cardiovasc Surg

Chest

Am J Cardiol

J Thorac Cardiovasc Surg

Am J Cardiol

Impact of pulmonary regurgitation and right ventricular dysfunction on oxygen uptake recovery kinetics in repaired tetralogy of Fallot

Eur J Heart Fail

Ventilatory responses to exercise in adults after repair of tetralogy of Fallot

Br Heart J

Long-term results of total repair of tetralogy of Fallot in childhood

Ann Thorac Surg

Congenital heart disease
Cardiac Magnetic Resonance Imaging Correlates of Exercise Capacity in Patients With Surgically Repaired Tetralogy of Fallot