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Exercise echocardiography demonstrates biventricular systolic dysfunction and reveals decreased left ventricular contractile reserve in children after tetralogy of Fallot repair . BACKGROUND Long-term biventricular systolic performance is a key determinant of clinical outcomes late after tetralogy of Fallot ( TOF ) repair . A need exists for early indices of both left ventricular ( LV ) and right ventricular ( RV ) compromise in this population . METHODS Twenty-nine children ( age range , 5-18 years ) with repaired TOF and 44 healthy controls were prospectively evaluated . M-mode and tissue Doppler data were obtained for each ventricle and the RV outflow tract at rest and during semisupine bicycle exercise . By making measurements of myocardial acceleration during isovolumic contraction during exercise , at increasing heart rates , LV force-frequency curves were constructed . Patients also underwent cardiac magnetic resonance imaging , cardiopulmonary exercise testing , and measurement of serum neurohormonal markers . RESULTS Children with repaired TOF had dilated right ventricles ( RV end-diastolic volume index = 153 ± 37.3 mL/m ( 2 ) ) but normal ejection fractions as measured on magnetic resonance imaging ( LV ejection fraction = 59.3 ± 6.2 % , RV ejection fraction = 50.2 ± 8.5 % ) and normal serum neurohormonal markers . Detailed resting echocardiography detected abnormal ventricular function , worst in the right ventricle and RV outflow tract . Exercise exacerbated these findings and provoked significant decline in LV indices . The LV force-frequency curves of patients were attenuated , with an early plateau and inadequate increase of isovolumic contraction . Correlations were seen between peak exercise LV isovolumic contraction and percentage predicted peak oxygen uptake ( r = 0.51 , P = .02 ) , LV and RV ejection fractions ( r = 0.41 , P = .03 ) , and RV and LV long-axis fractional shortening ( r = 0.44 , P = .02 ) . CONCLUSIONS The postsurgical pathophysiology of TOF begins early after repair . At a time when clinically well and while routine indices of heart function remain normal , children with repaired TOF exhibit RV dilatation and subtle , interlinked biventricular abnormalities on resting echocardiography . Exercise echocardiography provides additional information and reveals abnormal LV excitation-contractile coupling that may be linked to impaired exercise capacity .
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Intervention_Surgical
tetralogy of Fallot ( TOF ) repair .
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Intervention_Other
M-mode and tissue Doppler data
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Intervention_Physical
semisupine bicycle exercise .
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Intervention_Physical
cardiac magnetic resonance imaging
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Intervention_Physical
cardiopulmonary exercise testing
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Participant_Condition
after tetralogy of Fallot repair
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Participant_Sample-size
Twenty-nine
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Participant_Age
children ( age range , 5-18 years )
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Participant_Condition
with repaired TOF
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Participant_Condition
repaired TOF exhibit RV dilatation and subtle