Patients with repaired tetralogy of Fallot exhibited disrupted biventricular kinetic energy balance, including significantly decreased diastolic LV %KEz (62% vs 72%) compared to normal controls.
Observational (n=96)
Does MR tissue phase mapping reveal differential adaptation of biventricular myocardial kinetic energy in patients with repaired tetralogy of Fallot compared to normal controls?
MR tissue phase mapping reveals disrupted biventricular myocardial kinetic energy proportions in repaired tetralogy of Fallot, which correlate with pulmonary regurgitation.
Background The myocardial kinetic energy ( KE ) and its association with pulmonary regurgitation ( PR ) have yet to be investigated in repaired tetralogy of Fallot ( rTOF ) patients. Purpose To evaluate the adaptation of myocardial KE in rTOF patients by tissue phase mapping (TPM). Study Type Prospective. Population A total of 49 rTOF patients (23 ± 5 years old; male = 32), 47 normal controls (22 ± 1 year old; male = 29). Field Strength/Sequence 3‐T/2D dark‐blood three‐directional velocity‐encoded gradient‐echo sequence. Assessment Left and right ventricle ( LV , RV ) myocardial KE in radial ( KE r ), circumferential ( KE ø ), longitudinal ( KE z ) directions. The proportions of KE in each direction to the sum of all KE ( KE røz ): % KE r , % KE ø , % KE z . PR fraction. Statistical Test Student's t test, multivariable regression. Statistical significance: P < 0.05. Results In rTOF group, LV KE z remained normal in systole ( P = 0.565) and diastole ( P = 0.210), whereas diastolic LV %KE z (62% ± 14% vs. 72% ± 7%) and systolic LV %KE ø (9% ± 6% vs. 20% ± 7%) were significantly decreased. The KE r and %KE r of both ventricles significantly increased in the rTOF group (RV in diastole: 6 ± 3 vs. 3 ± 1 μJ and 54% ± 13% vs. 27% ± 7%). The rTOF group exhibited significantly higher RV/LV ratios of %KE r (systole: 1.3 ± 0.3 vs. 1.0 ± 0.3) and %KE ø (systole: 1.6 ± 0.8 vs. 1.0 ± 0.3) and significantly lower ratios of %KE z in systole (0.7 ± 0.2 vs. 1.0 ± 0.1) and diastole (0.5 ± 0.2 vs. 0.9 ± 0.1). In multivariable regression analysis, the RV peak systolic KE røz , RV systolic KE z , and LV diastolic %KE ø were independently associated with PR fraction in the rTOF group (adjusted R 2 = 0.479). Data Conclusion In rTOF patients, the adaptation of the KE proportion occurred earlier than that of the KE amplitude, and the biventricular balance of %KE was disrupted. PR may cause differential KE adaptation in RV and LV. TPM‐derived KE may be useful in investigation of myocardial adaptation in rTOF patients. Evidence Level 2 Technical Efficacy Stage 3
Ke et al. (Mon,) conducted a observational in Repaired tetralogy of Fallot (n=96). Repaired tetralogy of Fallot vs. Normal controls was evaluated on Left and right ventricle myocardial kinetic energy (KE) in radial, circumferential, and longitudinal directions. Patients with repaired tetralogy of Fallot exhibited disrupted biventricular kinetic energy balance, including significantly decreased diastolic LV %KEz (62% vs 72%) compared to normal controls.