Evaluating Biventricular Myocardial Velocity and Interventricular Dyssynchrony in Adult Patients During the First Year After Heart Transplantation

Background Magnetic resonance tissue phase mapping (TPM) measures three‐directional myocardial velocities of the left and right ventricle (LV, RV). This noninvasive technique may supplement endomyocardial biopsy (EMB) in monitoring grafts post‐heart transplantation (HTx). Purpose To assess biventricular myocardial velocity alterations in grafts and investigate the relationship between velocities and acute cellular rejection (ACR) episodes. Study Type Prospective. Subjects Twenty‐seven patients within 1 year post‐HTx (49 ± 13 years, 19 M) and 18 age‐matched controls (49 ± 15 years, 12 M). Field Strength/Sequence 1.5T, 2D balanced steady‐state free precession, and TPM. Assessment Ventricular function: end‐diastolic and end‐systolic volumes, stroke volumes, ejection fraction (EF), and myocardial mass. TPM velocities: peak‐systolic and peak‐diastolic velocities, cardiac twist, and interventricular dyssynchrony. ACR rejection episodes: International Society for Heart and Lung Transplantation grading of EMB specimens. Statistical Tests The Lilliefors test for normality, unpaired t‐tests, and Wilcoxon rank‐sum tests for normally and nonnormally distributed data, respectively, were used, as well as multivariate regression for confounding variables and Pearson's correlation for associations between TPM velocities and global function. Results Compared to controls, HTx patients demonstrated reduced biventricular systolic longitudinal velocities (LV: 5.2 ± 2.1 vs. 4.0 ± 1.5 cm/s, P