Pulmonary Function and Limitations to Exercise Capacity Following Repair of Transposition of the Great Vessels: Atrial Baffle Versus Arterial Switch (original) (raw)
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Pediatric Cardiology, 2011
This study evaluated resting pulmonary function and its impact on exercise capacity after atrial baffle (BAF-FLE) and arterial switch (SWITCH) repair of D-transposition of the great vessels (DTGV). Previously decreased exercise capacity in DTGV patients has been primarily attributed to cardiovascular limitations, whereas pulmonary limitations have largely been overlooked. Resting flow volume loops were compared for BAFFLE (n = 34) and SWITCH (n = 32) patients. Peak exercise variables were compared for BAFFLE (n = 30) and SWITCH (n = 25). Lung disease (restrictive and/or obstructive) was present in 53% of DTGV patients (BAFFLE 62% and SWITCH 44%; p = 0.14). BAFFLE patients had a normal breathing reserve, whereas that of SWITCH patients was decreased (27.3 ± 28.3 vs. 13.0 ± 19.2; p = 0.04). BAFFLE patients attained a lower percent of predicted peak oxygen pulse (82.7 ± 20.5% vs. 94.7 ± 19.3%; p = 0.04) and peak oxygen consumption (VO 2peak ) (26.6 ± 6.7 ml/kg/min vs. 37.3 ± 8.5 ml/kg/min; p \ 0.01) than SWITCH patients. Patients after surgical repair for DTGV have an underappreciated occurrence of lung disease, even post-SWITCH. SWITCH patients have diminished breathing reserves, suggesting a pulmonary limitation to VO 2peak . BAFFLE patients have lower VO 2peaks , greater breathing reserves, and lower oxygen pulses than SWITCH patients, suggesting a cardiac limitation to peak aerobic capacity with probable secondary pulmonary limitations. Treating underlying lung disease in symptomatic patients after repair of DTGV may improve functional status.
The American Journal of Cardiology, 2010
Patients with anatomic repair of transposition of the great arteries (TGA) can present with branch pulmonary artery (PA) stenosis; however, its relation to an abnormal cardiopulmonary response to exercise is unknown. We investigated the relation between the PA anatomy and pulmonary blood flow (PBF) distribution and the cardiopulmonary response to exercise in patients with anatomic repair of TGA. We used cardiopulmonary exercise testing and magnetic resonance imaging to study 55 consecutive patients (62% male; age 14.4 ؎ 2.3 years) who had undergone neonatal anatomic repair of TGA. The peak oxygen uptake and slope of carbon dioxide elimination/minute ventilation was 79 ؎ 15% of predicted and 29.8 ؎ 3.8, respectively. Abnormal peak oxygen uptake (R ؍ 0.363, p ؍ 0.0082) and slope of carbon dioxide elimination/minute ventilation (R ؍ 0.612, p <0.0001) values were associated with an abnormal right/left PBF distribution. However, although an increased ventilatory response to exercise appeared to be primarily related to an abnormal right/left PBF distribution, exercise capacity appeared to be related to the extent of the proximal PA branches and main PA stenosis (R ؍ 0.476, p ؍ 0.0004), suggesting that mechanical obstruction to PBF during exercise could be the main mechanism causing an abnormal exercise capacity. In conclusion, an abnormal PBF distribution related to branch PA stenosis or hypoplasia was associated with a reduced exercise capacity and increased ventilatory drive during exercise in patients with anatomic repair of TGA. Cardiopulmonary exercise test data can complement the anatomic and magnetic resonance imaging data in selecting those lesions that are functionally important.
European Heart Journal, 2001
Aims This study compares the functional outcome and cardiorespiratory response to exercise, in patients who have undergone arterial switch for transposition of the great arteries, with normal controls and patients who have undergone atrial switch operation. Methods and Results Fifteen patients who had undergone arterial switch (mean age 8•5 2•9 years) were compared to 32 patients who had undergone atrial switch (9•2 1•8 years) and 27 normal controls (8•5 2•1 years). Exercise testing was performed on a treadmill and gas exchange measured breath-by-breath. Aerobic capacity, assessed by determination of the ventilatory anaerobic threshold, averaged 91 7•8% of normal (95% confidence limits: 92-108%) for arterial switch and 75•1 13•1% for atrial switch (P<0•001 patients vs normals). Aerobic exercise function was evaluated by calculation of the slope of oxygen uptake vs exercise intensity. The mean value for this slope was 2•0 0•25 for arterial switch, 2•5 0•46 for normals and 1•7 0•80 for atrial switch (P<0•05; patients vs normals). Efficiency of the pulmonary gas exchange was assessed by calculation of the slope of ventilation vs carbon dioxide output during exercise. This averaged 38•7 14•7 for arterial switch, 48•1 14•1 for atrial switch and 30•3 7•6 for normals (P<0•001; patients vs normals). Conclusion Cardiorespiratory exercise function is at, or slightly below, the lower limit of normal in patients with arterial switch, while the lowest values were observed for those who had undergone atrial switch.
American Journal of Cardiology, 2009
Patients who undergo the arterial switch operation for transposition of the great arteries (TGA) are at risk of reduced exercise capacity, with most reports focusing on chronotropic incompetence as the cause. Residual right ventricular outflow tract (RVOT) obstruction is relatively common after the arterial switch operation, but its effect on exercise capacity is unknown. We studied 60 patients (44 males, age 13.3 ؎ 3.4 years) who had undergone a neonatal arterial switch operation using the cardiopulmonary exercise test and transthoracic echocardiography. The peak exercise oxygen uptake (VO 2 ), and heart rate were recorded and are expressed as the percentage of predicted values. The greatest velocity detected by echocardiography across the pulmonary valve, pulmonary trunk, or pulmonary branches was used in the analysis as an index of RVOT obstruction. The peak VO 2 % was 84 ؎ 15%, and the peak heart rate percentage was 97 ؎ 8%. Of the 60 patients, 29 had an abnormal peak VO 2 % (<84%) and 3 (5%) had an abnormal peak heart rate percentage (<85%). The maximal RVOT velocity was 2.3 ؎ 0.6 m/s, and it correlated with the peak VO 2 % (r ؍ ؊0.392, p ؍ 0.004). On multivariate analysis, the presence of residual RVOT obstruction (p ؍ 0.0007) was the only variable associated with a reduced peak VO 2 %. Patients with a RVOT maximal velocity >2.5 m/s had a lower peak VO 2 % than those with lower velocities (p <0.0001). No relation was found between age at testing and the peak VO 2 %. In conclusion, a reduced exercise capacity is relatively common in children and young adults who have undergone an arterial switch operation, but it does not decrease with age. The presence of residual RVOT obstruction seems to have an effect on exercise capacity.
Exercise capacity in adult patients with congenitally corrected transposition of the great arteries
Heart (British Cardiac Society), 2001
To examine cardiopulmonary values, static lung function, and ejection fraction in adult patients with congenitally corrected transposition of the great arteries (CCTGA). 41 patients who had undergone static lung function testing and cardiopulmonary exercise tests with measurements of ejection fraction were identified at the Toronto Congenital Cardiac Centre for Adults. Aerobic capacity in patients with CCTGA was severely diminished, varying from 30-50% of the results achieved by healthy subjects. Normal values of right ventricular and left ventricular ejection fraction were found. However, the systemic right ventricular ejection fraction increased by 2% from rest to exercise, as opposed to the expected > 5% increase in a healthy population. The pulmonary left ventricular ejection fraction decreased by 2% at peak exercise. Diminished values of heart rate, forced expiratory volume in one second (FEV(1)), forced vital capacity, and systolic blood pressure compared to the predicted v...
Pulmonary Circulation, 2014
Patients with early repair of an isolated atrial septal defect (ASD) are expected to have unremarkable right ventricular (RV) and pulmonary circulation physiology. Some studies, however, suggest persistent functional impairment. We aimed to examine the role of abnormal RV and pulmonary vascular response to exercise in patients who had undergone ASD closure. Using a previously published data set, we reviewed invasive exercise cardiopulmonary testing with right-sided hemodynamic data for 12 asymptomatic patients who had undergone ASD closure. The 5 (42%) patients with impaired maximal oxygen uptake (V : o 2max ) were older and exhibited a lower peak cardiac index (5.6 AE 0.8 vs. 9.0 AE 1.2 L/min/m 2 ; P ¼ .005) because of abnormal stroke volume augmentation (þ3.2 AE 3.9 vs. þ17.4 AE 10.2 mL/m 2 ; P ¼ .02). While all resting hemodynamic variables were similar, patients with low V :
Journal of Cardiology, 2020
Background: The arterial switch operation (ASO) for transposition of the great arteries has excellent survival, but a substantial number of patients suffer from a reduced exercise capacity. The goal of this study was to identify imaging parameters associated with a reduced exercise capacity in patients after ASO. Methods: A retrospective analysis was performed of ASO patients who underwent cardiopulmonary exercise testing (CPET) between 2007 and 2017. Reduced exercise performance was defined as a reduced workload peak (W peak) with Z-score <À2 or a peak oxygen uptake indexed for weight (VO 2peak /kg) with Z-score <À2. Data on echocardiography and cardiac magnetic resonance performed within 1 year of the CPET were collected for comparison. Results: A total of 81 ASO patients (age 17 AE 7 years) were included. Reduced exercise performance was found in 22 patients (27%) as expressed by either a reduced W peak and/or a reduced VO 2peak /kg. Main pulmonary artery gradient and tricuspid regurgitation gradient by echocardiography were found to be associated with reduced W peak (p = 0.031; p = 0.020, respectively). The main pulmonary artery gradient and tricuspid regurgitation gradient by echocardiography were found to be associated with reduced VO 2peak /kg (p = 0.009; p = 0.019, respectively). No left ventricular parameters were found to be associated with abnormal exercise performance. Conclusion: This study demonstrates that ASO patients frequently experience reduced exercise capacity. Echocardiographic evidence of main pulmonary artery stenosis and increased right ventricular pressure were associated with reduced exercise capacity, and are therefore key to monitor during serial follow-up of ASO patients.
Declining Aerobic Capacity of Patients with Arterial and Atrial Switch Procedures
Pediatric Cardiology, 2009
Background Patients with transposition of the great arteries corrected by an atrial switch procedure are believed to have a worse physical outcome than patients with an arterial switch procedure correction. This study aimed to compare exercise data for patients with the two surgical methods. Methods This study retrospectively analyzed exercise treadmill test results for 7-to 17-year-old patients who underwent either an atrial switch procedure (n = 45) or an arterial switch procedure (n = 44). The results were compared with reference material. Results Both groups showed significantly less aerobic capacity than healthy subjects. The atrial switch patients achieved 69% of reference status, and the arterial switch patients achieved 82%. A gradual decline in exercise capacity with increasing age was shown for patients with atrial switch circulation (p \ 0.0001). No significant difference was found for the arterial switch group (p = 0.319). Conclusions Significantly less aerobic capacity was found in atrial and arterial switch patients than in healthy subjects. A decline in aerobic capacity with increasing age was found in the atrial switch patients. However, the small number of teenagers in the arterial switch group limits the ability to be conclusive. The results indicate that chronotropic incompetence may be one of the reasons for diminishing capacity. The decline in exercise performance leads the authors to recommend regular follow-up exercise testing.
Journal of Cardiovascular Magnetic Resonance, 2018
Background: Maldistribution of pulmonary artery blood flow (MPBF) is a potential complication in patients who have undergone single ventricle palliation culminating in the Fontan procedure. Cardiovascular magnetic resonance (CMR) is the best modality that can evaluate MPBF in this population. The purpose of this study is to identify the prevalence and associations of MPBF and to determine the impact of MPBF on exercise capacity after the Fontan operation. Methods: This retrospective single-center study included all patients after Fontan operation who had maximal cardiopulmonary exercise test (CPET) and CMR with flow measurements of the branch pulmonary arteries. MPBF was defined as > 20% difference in branch pulmonary artery flow. Exercise capacity was measured as percent of predicted oxygen consumption at peak exercise (% predicted VO 2). Linear and logistic regression models were used to determine univariate and multivariable predictors of exercise capacity and correlates of MPBF, respectively. Results: A total of 147 patients who had CMR between 1999 and 2017 were included (median age at CMR 21.8 years [interquartile range (IQR) 16.5-30.6]) and the median time between CMR and CPET was 2.8 months [IQR 0-13.8]. Fiftythree patients (36%) had MPBF (95% CI 29-45%). The mean % predicted VO 2 was 63 ± 16%. Patients with MPBF had lower mean % predicted VO 2 compared to patients without MPBF (60 ± 14% versus 65 ± 16%, p = 0.04). On multivariable analysis, a lower % predicted VO 2 was independently associated with longer time since Fontan, higher ventricular mass-to-volume ratio, and MPBF. On multivariable analysis, only compression of the branch pulmonary arteries by the ascending aorta or aortic root was associated with MPBF (OR 6.5, 95% CI 5.6-7.4, p < 0.001). Conclusion: In patients after the Fontan operation, MPBF is common and is independently associated with lower exercise capacity. MPBF was most likely to be caused by pulmonary artery compression by the aortic root or the ascending aorta. This study identifies MPBF as an important risk factor and as a potential target for therapeutic interventions in this fragile patient population.