Comparison of 2 Myocardial Velocity Gradient Assessment Methods During Dobutamine Infusion with Doppler Myocardial Imaging☆,☆☆
Section snippets
Animal Preparation
Eight chronically instrumented, conscious adult mongrel dogs weighing 22 to 28 kg were investigated. As previously reported,7 dogs were instrumented for the measurement of arterial pressure, LV pressure, and LV dP/dt. All experiments were conducted when the dogs were healthy, apyretic, and had been trained to lie quietly on the experiment table. Examinations were performed at steady state before and during dobutamine infusion (10 μg/kg per minute for 15 minutes). Data were continuously recorded
RESULTS
The feasibility of color M-mode DMI was 100%. There was a significant positive correlation between MVG obtained from the thickness-velocity plot method and from the time-velocity plot method (r = 0.82, P < .0001). There was a close agreement between the 2 MVG assessment methods. The bias (mean difference in MVG between the 2 methods) of all measurements was –0.17 ± 9.71 seconds-1 . MVG values obtained by the time-velocity plot method were significantly higher than those obtained by the
DISCUSSION
DMI has been shown to be reliable for addressing ventricular wall mechanical events related to cardiac function through measurements of wall velocities.4, 14, 15, 16, 17, 18 MVG was first described by McVeigh and Zerhouni19 with the use of magnetic resonance tagging and by Fleming et al20 with the use of color M-mode DMI. MVG has been shown to represent regional wall motion independent of overall cardiac translation in the chest.2, 3 In the current study, MVG was calculated on conscious dogs in
CONCLUSIONS
Our study showed that 2 complementary methods may be applied to MVG assessment and enabled objective interpretation of dobutamine effects on LV wall motion. For the first time, quantitative criteria have been used for assessing MVG, and its range values have been given in normal hearts at baseline and during dobutamine infusion. In addition to the thickness-velocity plot method, the time-velocity plot method only provides peak velocity during each cardiac phase, sequential changes in LV wall
References (32)
- et al.
Comparative usefulness of myocardial velocity gradient in detecting ischemic myocardium by a dobutamine challenge
J Am Coll Cardiol
(1998) - et al.
Usefulness of myocardial velocity gradient derived from 2-dimensional tissue Doppler imaging as an indicator of regional myocardial contraction independent of translational motion assessed in atrial septal defect
Am J Cardiol
(1997) - et al.
Myocardial velocity gradient as a new indicator of regional LV contraction: detection by a two-dimensional tissue Doppler imaging technique
J Am Coll Cardiol
(1995) - et al.
Differences in myocardial velocity gradient measured throughout the cardiac cycle in patients with hypertrophic cardiomyopathy, athletes and patients with LV hypertrophy due to hypertension
J Am Coll Cardiol
(1997) - et al.
Quantification of the myocardial response to low-dose dobutamine using tissue Doppler echocardiography measures of velocity and velocity gradient
Am J Cardiol
(1998) - et al.
Preejectional LV wall motion in normal subjects using Doppler tissue imaging and correlation with ejection fraction
Am J Cardiol
(1997) - et al.
Colour Doppler velocity imaging of the myocardium
Ultrasound Med Biol
(1992) - et al.
Color Doppler myocardial imaging: a new technique for the assessment of myocardial function
J Am Soc Echocardiogr
(1994) - et al.
New method for evaluating LV wall motion by color-coded tissue Doppler imaging: in vitro and in vivo studies
J Am Coll Cardiol
(1995) - et al.
Color-coded measures of myocardial velocity throughout the cardiac cycle by tissue Doppler imaging to quantify regional LV function
Am Heart J
(1996)
Myocardial wall velocity assessment by pulsed Doppler tissue imaging: characteristic findings in normal subjects
Am Heart J
Dobutamine in chronic ischemic heart failure: alterations in LV function and coronary hemodynamics
Am J Cardiol
Effects of dobutamine on myocardial blood flow, contractile function and bioenergetic responses distal to coronary stenosis: implications with regard to dobutamine stress testing
Am Heart J
Heterogeneity of LV segmental wall thickening and excursion in 2-dimensional echocardiograms of normal human subjects
Am J Cardiol
Age-related transmural peak mean velocities and peak velocity gradients by Doppler myocardial imaging in normal subjects
Eur Heart J
Role of vascular endothelium in exercise-induced dilation of large epicardial coronary arteries in conscious dogs
Circulation
Cited by (18)
Clinical Relevancy of the Myocardial Velocity Gradient: Limitations of a Binary Response
2003, Journal of the American Society of EchocardiographyDynamic myocardial velocity changes between phases of the cardiac cycle
2003, Ultrasound in Medicine and BiologyDiastolic response during dobutamine stress echocardiography evaluated by a tissue velocity imaging technique is a sensitive indicator for diagnosing coronary artery disease
2003, Journal of the American Society of EchocardiographyMyocardial velocity gradient reflects the severity of myocardial damage regardless of the presence or absence of mitral regurgitation
2003, Journal of the American Society of EchocardiographyAssessment of normal and ischaemic myocardium by quantitative M-mode tissue doppler imaging
2002, Ultrasound in Medicine and BiologyCitation Excerpt :Previous studies (Sabbah et al. 1981) proved that the subendocardium undergoes greater thickening and shortening than the epicardium; Sagar and colleagues found functional changes in the epi- and endocardium layers during ischaemia (Sagar et al. 1987). Myocardial gradient has been reported to be a good indicator of contractility defects in ischaemic segments (Garot et al. 1999; Pellerin et al. 1999). Other alternatives to evaluate myocardial contraction on M-mode grey-scale images have been explored, such as myocardial wall thickening and thinning (Guth et al. 1984; Jamal et al. 2001) obtained as the ratio between systole and diastole wall width.
Quantitative analysis of hibernating myocardium by dobutamine tissue Doppler echocardiography
2001, American Journal of Cardiology
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Reprint requests: Dr Denis Pellerin, Service de Cardiologie, Hopital Universitaire de Bicetre, 78, rue du General Leclerc, 94270 Le Kremlin-Bicetre, France.
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