Doppler myocardial velocity gradient as a new diagnostic index for the assessment of myocardial disease
Palka, P.; Lange, A.; Burstow, D.
Polski Merkuriusz Lekarski Organ Polskiego Towarzystwa Lekarskiego 11(61): 72-78
2001
ISSN/ISBN: 1426-9686 PMID: 11579838 Document Number: 526857
Currently, echocardiography is the technique of choice in the noninvasive assessment of left ventricular (LV) function. Unlike the assessment of LV systolic function, its role is limited in the quantification of LV diastolic function where only global LV filling can be assessed. Tissue Doppler echocardiography (TDE) is a recently introduced imaging technique which allows for direct assessment of LV myocardial contraction and relaxation. Therefore, parameters derived from TDE showed provide a more accurate assessment of LV systolic and diastolic function. Doppler myocardial velocity gradient (MVG) is a new parameter derived from TDE, which enables the measurement of the spatial distribution of transmyocardial velocities over the cardiac cycle. The most studied application of this technique relates to the earlier and more sensitive diagnosis of different forms of cardiomyopathy. Based on the Doppler MVG measurement, patients with ischaemic cardiomyopathy can be differentiated from those with idiopathic dilated cardiomyopathy. In both diseases MVG is reduced in systole, but as opposed to dilated cardiomyopathy, MVG in patients with ischaemic cardiomyopathy is also markedly reduced in early diastole. MVG derived from TDE also provides new diagnostic insights into genetically determined heart muscle diseases. It has been shown that an early diastolic MVG < or = 7 s-1 is characteristic for patients with hypertrophic cardiomyopathy and differentiates this group of patients from 'athletes' heart, independently of the degree of LV hypertrophy. A recent study has also shown that in Friedreich ataxia related cardiomyopathy there is a close relation between the degree of genotype abnormalities and the degree of reduction in the MVG. Also, the assessment of Doppler MVG enables the differentiation of restrictive cardiomyopathy from constrictive pericarditis. Based on available literature it appears that TDE derived MVG enhances the information available from conventional echocardiography and helps to establish an earlier diagnosis in patients with primary and secondary myocardial diseases.