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Maximal voluntary exercise variables in children with postoperative coarctation of the aorta
S M Balderston1, E Daberkow, D R Clarke
1University of Colorado Health Sciences Center, Denver.
Insights
Children with repaired coarctation of the aorta show excellent exercise capacity and normal blood pressure post-surgery. These findings indicate satisfactory cardiopulmonary function after surgical repair in childhood.
Area of Science:
- Pediatric Cardiology
- Cardiovascular Surgery
- Exercise Physiology
Background:
- Coarctation of the aorta is a congenital heart defect requiring surgical intervention.
- Long-term outcomes and exercise capacity in children post-coarctation repair are critical for assessing treatment success.
Purpose of the Study:
- To evaluate the cardiopulmonary function and exercise capacity in children following surgical repair of coarctation of the aorta.
- To compare exercise variables between repaired coarctation patients and a healthy control group.
Main Methods:
- Maximal graded bicycle ergometry and expiratory gas measurement (mass spectrometry) were used in 31 children post-coarctation repair.
- Exercise testing was conducted using the James protocol, with results compared to 22 age- and gender-matched healthy controls.
Main Results:
- Patients achieved excellent peak heart rate (94.6% predicted) and mean power (111% predicted).
- Maximal oxygen consumption was 89% of predicted, with an anaerobic threshold at 63% of exercise time; these were comparable to controls.
- Peak systolic blood pressure during exercise was similar between groups; however, patients with associated intracardiac lesions had lower maximal oxygen consumption.
Conclusions:
- Satisfactory surgical repair of coarctation of the aorta before school age results in adequate cardiopulmonary function.
- Children demonstrate normal or above-average work capacity and normal exercise blood pressure after successful coarctation repair.
Abstract:
Thirty-one children with postoperative coarctation of the aorta underwent maximal graded bicycle ergometry using an electronically braked ergometer and the James protocol; 18 also underwent expiratory gas measurement using a mass spectrometer. Twenty-two age- and gender-matched normal subjects were used as a control group. The mean age at operation was 41 months and the mean age at evaluation was 134 months (mean follow-up interval 93 months). The original surgical repair was subclavian flap repair in 8 patients, end to end anastomosis in 21, patch aortoplasty in 1 patient and tubular graft in 1. Patients exercised until exhaustion and maximal exercise variables were obtained. The maximal voluntary peak heart rate was 183 beats/min (94.6% of predicted value), indicating excellent effort. Mean power was 111% of predicted value and, when measured, maximal oxygen consumption was 89% of predicted value with an anaerobic threshold at 63 +/- 3.5% of exercise time. The observed work variables were not different from values in the control group and were not affected by the type of repair. The mean peak systolic blood pressure was 152 +/- 7.6 mm Hg versus 147 +/- 5.7 mm Hg in the control group (p = NS). Patients who had associated intracardiac lesions had significantly lower maximal oxygen consumption (85 +/- 3% vs. 98 +/- 4% of predicted value). The results suggest that adequate cardiopulmonary function, normal or above average work capacity and normal exercise systolic blood pressure can be obtained in children with satisfactory repair of coarctation of the aorta performed before school age.