OBJECTIVE: Myocardial velocity gradient (MVG) is a recently introduced ultrasonic parameter which describes the spatial distribution of intramural myocardial velocities and their changes throughout the cardiac cycle. To determine the potential clinical role of the MVG, a group of patients with globally abnormal left ventricular systolic function was studied.
METHODS: The group comprised of 27 idiopathic dilated cardiomyopathy (DCM) patients (age 54 ± 6 years) and 25 age-matched healthy volunteers (HV) who served as a control group. MVG was measured across the left ventricular posterior wall throughout the cardiac cycle.
RESULTS: In the DCM group, MVG was significantly lower than in the HV group in systole during isovolumic contraction (IC): (0.2 ± 0.3) s−1 vs. (1.5 ± 0.9) s−1; P < 0.01 and ventricular ejection (VE) (1.4 ± 0.7) s−1 vs. (4.7 ± 0.9) s−1; P < 0.01, and in late diastole during atrial contraction (AC) (1.4 ± 1.1) s−1 vs. (3.3 ± 0.9) s−1; P < 0.01. Additionally, in those DCM patients who had a global restrictive filling pattern assessed by standard transmitral pulse-wave Doppler (11/27), MVG was higher (P < 0.01) in early diastole during rapid ventricular filling (RVF) (6.9 ± 1.4) s−1 compared to both normals (4.1 ± 1.2) s−1 and DCM AC (r = - 0.54; P < 0.01). Measurement of normalized peak rate of the left ventricular posterior wall thinning during RVF did not allow differentiation (P = NS) between DCM patients with restrictive filling pattern (5.9 _+ 2.9) s- ~ and DCM patients with non-restrictive pattern (4.8 _+ 2.4) s - ~.
CONCLUSION: In DCM patients, the decrease in MVG in systole and late diastole is in agreement with the clinical diagnosis of idiopathic dilated cardiomyopathy. MVG measured in early diastole would appear to be an accurate parameter which quantifies abnormal early diastolic left ventricular function in patients with global and regional myocardial dysfunction. This suggests that the measurement of MVG could be used to quantify myocardial systolic and diastolic performance
