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Use of quantitative two-dimensional color tissue Doppler imaging for assessment of left ventricular radial and longitudinal myocardial velocities in dogs

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  • 1 Unité de Cardiologie d'Alfort, Ecole Nationale Vétérinaire d'Alfort, 7 Avenue du Général de Gaulle, 94704 Maisons-Alfort cedex, France.
  • | 2 Equipe mixte INSERM-Université 00-01, Kremlin-Bicêtre, France.
  • | 3 Unité de Cardiologie d'Alfort, Ecole Nationale Vétérinaire d'Alfort, 7 Avenue du Général de Gaulle, 94704 Maisons-Alfort cedex, France.
  • | 4 UMR 181 Physiopathologie et Toxicologie Expérimentales, INRA-ENVT, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076 Toulouse, Cedex 03, France.
  • | 5 Unité de Cardiologie d'Alfort, Ecole Nationale Vétérinaire d'Alfort, 7 Avenue du Général de Gaulle, 94704 Maisons-Alfort cedex, France.
  • | 6 Equipe mixte INSERM-Université 00-01, Kremlin-Bicêtre, France.
  • | 7 Base Cinophile de l'Armée de Terre, Suippes, France.
  • | 8 Base Cinophile de l'Armée de Terre, Suippes, France.
  • | 9 Unité de Cardiologie d'Alfort, Ecole Nationale Vétérinaire d'Alfort, 7 Avenue du Général de Gaulle, 94704 Maisons-Alfort cedex, France.
  • | 10 Unité de Cardiologie d'Alfort, Ecole Nationale Vétérinaire d'Alfort, 7 Avenue du Général de Gaulle, 94704 Maisons-Alfort cedex, France.
  • | 11 Unité de Cardiologie d'Alfort, Ecole Nationale Vétérinaire d'Alfort, 7 Avenue du Général de Gaulle, 94704 Maisons-Alfort cedex, France.
  • | 12 Equipe mixte INSERM-Université 00-01, Kremlin-Bicêtre, France.
  • | 13 UMR 181 Physiopathologie et Toxicologie Expérimentales, INRA-ENVT, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076 Toulouse, Cedex 03, France.

Abstract

Objective—To determine left ventricular free wall (LVFW) radial and longitudinal myocardial contraction velocities in healthy dogs via quantitative 2-dimensional color tissue Doppler imaging (TDI).

Animals—100 dogs.

Procedure—TDI was used by a single trained observer to measure radial and longitudinal myocardial movement in the LVFW. Radial myocardial velocities were recorded in segments in the endocardial and epicardial layers of the LVFW, and longitudinal velocities were recorded in segments at 3 levels (basal, middle, apical) of the LVFW.

Results—LVFW velocities were higher in the endocardial layers than in the epicardial layers. Left ventricular free wall velocities were higher in the basal segments than in the middle and apical segments. Radial myocardial velocity gradients, defined as the difference between endocardial and epicardial velocities, were (mean ± SD) 2.5 ± 0.8 cm/s, 3.8 ± 1.5 cm/s, and 2.3 ± 0.9 cm/s in systole, early diastole, and late diastole, respectively. Longitudinal myocardial velocity gradients, defined as the difference between basal and apical velocities, were 5.9 ± 2.2 cm/s, 6.9 ± 2.5 cm/s, and 4.9 ± 1.7 cm/s in systole, early diastole, and late diastole, respectively. A breed effect was detected for several systolic and diastolic TDI variables. In all segments, systolic velocities were independent of fractional shortening.

Conclusions and Clinical Relevance—LVFW myocardial velocities decreased from the endocardium to the epicardium and from base to apex, thus revealing intramyocardial radial and longitudinal velocity gradients. These indices could enhance conventional echocardiographic analysis of left ventricular function in dogs. Breed-specific reference intervals should be defined. (Am J Vet Res 2005;66:953–961)

Abstract

Objective—To determine left ventricular free wall (LVFW) radial and longitudinal myocardial contraction velocities in healthy dogs via quantitative 2-dimensional color tissue Doppler imaging (TDI).

Animals—100 dogs.

Procedure—TDI was used by a single trained observer to measure radial and longitudinal myocardial movement in the LVFW. Radial myocardial velocities were recorded in segments in the endocardial and epicardial layers of the LVFW, and longitudinal velocities were recorded in segments at 3 levels (basal, middle, apical) of the LVFW.

Results—LVFW velocities were higher in the endocardial layers than in the epicardial layers. Left ventricular free wall velocities were higher in the basal segments than in the middle and apical segments. Radial myocardial velocity gradients, defined as the difference between endocardial and epicardial velocities, were (mean ± SD) 2.5 ± 0.8 cm/s, 3.8 ± 1.5 cm/s, and 2.3 ± 0.9 cm/s in systole, early diastole, and late diastole, respectively. Longitudinal myocardial velocity gradients, defined as the difference between basal and apical velocities, were 5.9 ± 2.2 cm/s, 6.9 ± 2.5 cm/s, and 4.9 ± 1.7 cm/s in systole, early diastole, and late diastole, respectively. A breed effect was detected for several systolic and diastolic TDI variables. In all segments, systolic velocities were independent of fractional shortening.

Conclusions and Clinical Relevance—LVFW myocardial velocities decreased from the endocardium to the epicardium and from base to apex, thus revealing intramyocardial radial and longitudinal velocity gradients. These indices could enhance conventional echocardiographic analysis of left ventricular function in dogs. Breed-specific reference intervals should be defined. (Am J Vet Res 2005;66:953–961)