How is the peri-patch myocardium in ventricular septal defect patch repair?

Strain rate (SR) and strain (ɛ) in tissue Doppler imaging provide new noninvasive measurements of myocardial function, independent of heart motion.This study assesses the extent of peri-patch regional myocardial function after patch repair of ventricular septal defect (VSD).Myocardial SR and ɛ were recorded from the peri-patch myocardium and remote septum from patch area in 18 patients (1 month to 4 years of age, mean 2.3 years). Distance between the patch and the point of returning to remote normal strain (ɛ) profile was measured.Compared to the remote myocardial region, peri-patch myocardium had decreased peak longitudinal SR (−3.8 ± 2.1 s−1 vs. −5.3 ± 3.3 s−1, p < 0.05), delayed time to peak longitudinal SR (144 ± 59 ms vs. 110 ± 46 ms, p < 0.05), decreased peak ɛ (longitudinal, −20.8 ± 8.1% vs. −28.7 ± 11.1%; radial, 20.1 ± 16.3% vs. 34.3 ± 22.4%, p < 0.01), and delayed time to peak ɛ (longitudinal, 314 ± 80 ms vs. 241 ± 63 ms; radial, 329 ± 99 ms vs. 265 ± 78 ms, p < 0.0001).The mean distance from the patch to the remote patch ɛ curve was 2.55 ± 0.77 mm.ConclusionPeri-patch myocardium after repair of VSD has delayed and diminished contraction as compared to more remote normal myocardium.