RESUMO
To evaluate the details of myocardial dysfunction in dilated cardiomyopathy (DCM) patients using tagging images and the correlation of tagging imaging with tissue characteristics. Circumferential strain (Ecc) derived from tagging images was measured in 15 normal (NML) subjects (15 males; mean age 28.5 years) and 12 DCM patients (7 males; mean age 48.9 years). The following parameters were compared: (1) the magnitude of peak Ecc (Ecc*); (2) the coefficient of variation of the time of Ecc* (CVtime*), which indexes dyssynchrony; and (3) descriptive findings of time-Ecc curves. We also evaluated the correlations of Ecc* in DCM patients with ejection fraction (EF), myocardial T2 values, and late gadolinium enhancement (LGE). Mean Ecc*s in DCM patients and NML subjects were -12.7 and -23.5%, respectively (P < 0.0001). Mean CVtime*s were 15.2 and 4.5%, respectively (P = 0.0002). The findings of pre-systolic extension and systolic stretch in the septum were observed in 6 (50%) and 10 (83.3%) DCM patients and in none of the NML participants. Ecc* was correlated with EF (P < 0.0001, R2 = 0.90) and T2 values (P = 0.018, R2 = 0.44) but not with LGE (P = 0.072, R2 = 0.28). Tagging images revealed the reduction of myocardial function as well as dyssynchrony in DCM patients. Myocardial dysfunction occurred coincidently with myocardial inflammation.