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

AIMS: After tetralogy of Fallot (TOF) repair patients have right ventricular (RV) dysfunction and reduced exercise tolerance. Diastolic dysfunction may be important but is as yet poorly characterized. The early diastolic strain rate (SR) is a measure of ventricular relaxation, and may be useful to assess diastolic mechanics in TOF. We hypothesized that children after TOF repair have diastolic dysfunction and dyssynchrony by this measure, and sought to determine their relationship with pulmonary regurgitation (PR), RV enlargement, and aerobic exercise capacity.

METHODS AND RESULTS: We prospectively recruited asymptomatic children after TOF repair. RV and PR volumes were measured by magnetic resonance imaging; Doppler and tissue Doppler indices by echocardiography and RV and left ventricular (LV) early diastolic SR by two-dimensional speckle tracking. Exercise peak oxygen consumption (VO(2)) was determined using bicycle ergometry. Results were compared with healthy controls. We studied 53 TOF patients and 49 age-matched controls. TOF patients had significant PR (2.05 ± 1 L/m(2)) with moderate RV dilatation (157 ± 39 mL/m(2)), low-normal RV ejection fraction (49 ± 8.8%), and moderate QRS prolongation (141 ± 23 ms). The RV outflow gradient was 21.7 ± 16.0 mmHg. Patients had RV diastolic dysfunction vs. controls [reduced tricuspid valve (TV) E/A ratio, E' velocity, and longitudinal diastolic SR; increased right atrial volume and TV E/E' ratio]. LV early diastolic radial and circumferential SR were lower in TOF patients in association with more PR [parameter estimate (PE) 0.177 standard error (SE) (0.08) mL/m(2), P = 0.02] and higher RV volumes [(PE) 0.005 (0.002)mL/m(2), P = 0.01]. Diastolic dyssynchrony was not different in TOF patients vs. controls.

CONCLUSION: TOF patients have RV and LV diastolic dysfunction associated with RV enlargement and reduced early filling. SR imaging may be useful to quantify early myocardial diastolic dysfunction in these children.