Correlations between left ventricle regional systolic and diastolic functions determined by tissue Doppler echocardiography and myocardial perfusion determined by quantitative rest 99mTc MIBI gated SPECT in patients with dilated cardiomyopathy

OBJECTIVES
We investigated correlations between regional rest myocardial perfusion and regional systolic and diastolic myocardial velocities assessed by 99mTc MIBI gated single-photon emission computed tomography (G-SPECT) and tissue Doppler echocardiography, respectively, in dilated cardiomyopathy (DCM).

STUDY DESIGN
The study included 32 patients (27 men, 5 women; mean age 63±12 years) with DCM, with NYHA functional capacity II-IV. Twenty-five patients had ischemic, seven patients had nonischemic DCM. G-SPECT and tissue Doppler imaging studies were performed using short axis views of the basal, mid, and apical levels of the left ventricle, which was divided into 16 segments. For each segment, regional 99mTc MIBI uptake and peak systolic (Sm), and early (Em) and late (Am) diastolic velocities were determined.

RESULTS
The mean Sm value (p=0.007) was significantly higher and the mean 99mTc MIBI uptake (p<0.001) was significantly lower in ischemic patients. There was a very good correlation between ejection fractions obtained by the two methods in ischemic (r=0.81, p<0.001) and nonischemic (r=0.76, p=0.05) groups. Regional perfusion levels showed weak but significant correlations with Sm, Em, and Em/Am in the ischemic group. When 99mTc MIBI uptake levels of ischemic patients were assessed in four groups (≥75%, 75% to 50%, 50% to 25%, <25%), Sm values of the first two were significantly higher than that of the group with <25% uptake (p=0.007, p=0.002, respectively). Sm, Em, and Em/Am values were not correlated with 99mTc MIBI uptake in the nonischemic group.

CONCLUSION
Myocardial flow velocities determined by Doppler echocardiography are correlated with perfusion abnormalities detected by G-SPECT in ischemic DCM.