Relation of right ventricular mechanics to exercise tolerance in children after tetralogy of Fallot repair.

Progressive right ventricular (RV) dysfunction and exercise intolerance are common problems after tetralogy of Fallot (TOF) repair. We investigated RV myocardial deformation and dyssynchrony in children after TOF repair and their association with exercise capacity. Asymptomatic children after TOF repair were investigated by 2-dimensional speckle tracking echocardiography, magnetic resonance, and metabolic exercise study. Patients with RV outflow obstruction were excluded. Peak RV longitudinal strain and strain rate (SR) and dyssynchrony (RV intraventricular delay) were compared with healthy controls. Associations between RV strain, dyssynchrony, and exercise capacity were analyzed. Thirty-nine (81%) of 48 TOF patients and 40 healthy controls had adequate RV strain imaging. The TOF patients had moderately dilated RVs and normal RV ejection fraction. Right ventricular peak systolic strain (-23.2% ± 5.1% vs -28.5% ± 8.5%, P < .001) and SR (-1.46 ± 0.68 vs -2.1 ± 0.8, P < .001) were reduced in TOF patients compared with controls. Right ventricular intraventricular delay was higher in TOF patients (146.0 ± 159 vs 71.0 ± 92 milliseconds, P = .008). Decreased RV strain and SR were associated with increased RV dyssynchrony (strain parameter estimate [PE] 6.31 [2.30], P = .007; SR [PE] 11.32 [3.84], P = .004). Increased RV-left ventricular delay was associated with prolonged QRS duration (PE 0.13 [0.058], P = .03) and reduced RV ejection fraction (PE -2.95 [1.275], P = .02). Reduced RV peak SR was associated with decreased exercise peak oxygen uptake (PE 0.14 [0.07], P = .04). After repair of TOF, asymptomatic children have reduced RV deformation in association with RV dyssynchrony and reduced exercise tolerance.

Friedberg MK ，Fernandes FP ，Roche SL ，Slorach C ，Grosse-Wortmann L ，Manlhiot C ，Fackoury C ，McCrindle BW ，Mertens L ，Kantor PF ... -  《-》

Impaired right and left ventricular diastolic myocardial mechanics and filling in asymptomatic children and adolescents after repair of tetralogy of Fallot.

Friedberg MK ，Fernandes FP ，Roche SL ，Grosse-Wortmann L ，Manlhiot C ，Fackoury C ，Slorach C ，McCrindle BW ，Mertens L ，Kantor PF ... -  《-》

Impaired left ventricular myocardial mechanics and their relation to pulmonary regurgitation, right ventricular enlargement and exercise capacity in asymptomatic children after repair of tetralogy of Fallot.

Left ventricular (LV) dysfunction is common in adults late after repair of tetralogy of Fallot (TOF). The early detection of myocardial dysfunction may be important, but LV myocardial strain and dyssynchrony are not well studied in children with TOF. The objective of this study was to investigate LV strain and dyssynchrony in asymptomatic children and adolescents after contemporary repair of TOF. The hypothesis was that impaired LV myocardial mechanics are related to pulmonary regurgitation, right ventricular (RV) enlargement, and exercise capacity. Children and adolescents were prospectively studied after TOF repair. LV regional strain and dyssynchrony were assessed using two-dimensional speckle-tracking echocardiography. Ventricular volumes, ejection fraction, and pulmonary regurgitation were assessed using magnetic resonance imaging. Exercise capacity was determined using metabolic exercise testing. One hundred twenty-four subjects (53 patients with TOF and 71 controls) were studied. Regional circumferential (e.g., basal lateral wall, -15.0 ± 7.0% vs -19.0 ± 7.0%, P = .02) and radial (e.g., basal posterior wall, 32.0 ± 18.0% vs 48.0 ± 21.0%, P < .001) LV strain and longitudinal septal strain (-18.5 ± 3.5% vs -20.2 ± 2.8%, P = .01) were significantly reduced in patients with TOF compared with controls. LV mechanical dyssynchrony indices were not significantly different between groups (e.g., standard deviation of time to peak circumferential strain, 52.5 ± 40.4 vs 50.5 ± 27.1 msec, P = .81). Higher pulmonary regurgitation volume and larger RV end-diastolic volume were associated with decreased LV radial strain (P = .09). There was no association between LV longitudinal, radial, or circumferential dyssynchrony and indexed pulmonary regurgitation flow volume, RV end-diastolic volume, or RV ejection fraction. LV circumferential and radial strain are significantly reduced in children and adolescents after TOF repair and are associated with pulmonary regurgitation and RV dilatation. Resting LV mechanical dyssynchrony does not appear to contribute to early impaired LV strain in this population.

Fernandes FP ，Manlhiot C ，Roche SL ，Grosse-Wortmann L ，Slorach C ，McCrindle BW ，Mertens L ，Kantor PF ，Friedberg MK ... -  《-》

Relative Impact of Right Ventricular Electromechanical Dyssynchrony Versus Pulmonary Regurgitation on Right Ventricular Dysfunction and Exercise Intolerance in Patients After Repair of Tetralogy of Fallot.

Lumens J ，Fan CS ，Walmsley J ，Yim D ，Manlhiot C ，Dragulescu A ，Grosse-Wortmann L ，Mertens L ，Prinzen FW ，Delhaas T ，Friedberg MK ... -  《Journal of the American Heart Association》

Assessment of interventricular and right-intraventricular dyssynchrony in patients with surgically repaired tetralogy of Fallot by two-dimensional speckle tracking.

Mueller M ，Rentzsch A ，Hoetzer K ，Raedle-Hurst T ，Boettler P ，Stiller B ，Lemmer J ，Sarikouch S ，Beerbaum P ，Peters B ，Vogt M ，Vogel M ，Abdul-Khaliq H ... -  《-》