- Email: [email protected]
Computation of cardiac ventricular volumes from echocardiographic images
J Mol
130
Cell
Cardiol
22 (Supplement
IV)
(1990)
VIDEO MAPPING OF CARDIAC ACTIVATION. C.NASSIF, S.DILLON and AL.WIT. Dept. of Pharmacology, Columbia University, New York, NY, U.S.A. The goal of this work was to perform a high spatial resolution video mapping of cardiac activity. A 15 to 20 mm diameter area on the left ventricle of a Langendorff perfused(2 uM D600 in Tyrode) rabbit heart, stained with voltage sensitive dye (VSD) WW781(0.02 g/l) was illuminated by a 633 nm unfocused HeNe Laser beam. The VSD fluorescence was imaged through a 665 nm long pass filter with an 8 bits resolution, 0.07 Lux sensitivity CCD video camera synchronised with a DT2853 digital video frame grabber and a 3 Hz pacemaker. The optical information was stored and processed in a PCAT 80286 microcomputer. The phase of the pacing pulse was adjusted in 4 msec steps permitting activation spread on the illuminated surface to be followed. The Figure displays the 4 steps, 4 msec increment, in the activation of the surface. The surrounding dark halo is an artifact resulting from a low incident illumination. This high spatial resolution technique will permit detailed analysis of normal and abnormal impulse conduction.
_
”
--
131 RYANODINE RECEPTORS IN NORMAL AND HYPERTROPHIED RAT HEARTS. V. Naudin, P. Oliviero and D. Charlemagne. INSERM, Ul27, Hopital Lariboisiere, 75010 Paris, France. During a pressure overioad induced rat cardiac hypertrophy. the action potential duration is prolonged, and the calcium transient and the time to peak tension are delayed. It has been shown that these modifications which are related to modifications in the excitationcontraction coupling neither originate from changes in the dihydropyridine receptors density or calcium current nor from alterations in myofibrillar calcium sensitivity. These modifications may, however, be related to changes in the Ca induced Ca release process and therefore to the ryanodine receptors.We compared the total number, density and affinity of ryanodine receptors between homogenates from normal and hypertophied left ventricles. Preliminary results of [3H]ryanodine binding indicate that the density of ryanodine receptors at a saturating concentration of ryanodine is similar in normal and hypertrophied hearts while the total number of receptors increases with hypertrophy. Further experiments will be performed on purified sarcoplasmic reticulum preparations to confirm these results from which we hope their relevance to excitation-contraction coupling can be delineated.
132
COMPIJTATION OF CARDIAC VENTRICULAR VOLUMES FROM ECHOCARDJOGRAPHIC IMAGES. M. Neveu, A. Dipanda, H. Diebold, L. Dusserre. Laboratoire d’Informatique Medicale, Hopital du Borage C.H.R.U. DE DT.JON, B.P. 1542 21034 DIJDN CEDEX, France. Computation of cardiac ventricular volumes from echocardiographic images has to and 3D positionning of the probe. To face two problems : bad quality of images, solve these two problems, we have elaborated a 3D model of the ventricles with BSplines functions, that is more precise than classical ventricular models. We have also elaborated a method to detect edges on echographic images, based on texture Automatically detected edges by this method analysis and cardiologists knowledge. and the cardiologists hand drawn edges are not significatively different. Modeledges matching allows the model distortion and ventr-icular volumes computation. On theoretical soli.ds, volume computation using this method is quite accurate : the error is less than 5%. In viva validation is soon expected on animals as well as comparisons with classical methods (angiography). S.44
130
Cell
Cardiol
22 (Supplement
IV)
(1990)
VIDEO MAPPING OF CARDIAC ACTIVATION. C.NASSIF, S.DILLON and AL.WIT. Dept. of Pharmacology, Columbia University, New York, NY, U.S.A. The goal of this work was to perform a high spatial resolution video mapping of cardiac activity. A 15 to 20 mm diameter area on the left ventricle of a Langendorff perfused(2 uM D600 in Tyrode) rabbit heart, stained with voltage sensitive dye (VSD) WW781(0.02 g/l) was illuminated by a 633 nm unfocused HeNe Laser beam. The VSD fluorescence was imaged through a 665 nm long pass filter with an 8 bits resolution, 0.07 Lux sensitivity CCD video camera synchronised with a DT2853 digital video frame grabber and a 3 Hz pacemaker. The optical information was stored and processed in a PCAT 80286 microcomputer. The phase of the pacing pulse was adjusted in 4 msec steps permitting activation spread on the illuminated surface to be followed. The Figure displays the 4 steps, 4 msec increment, in the activation of the surface. The surrounding dark halo is an artifact resulting from a low incident illumination. This high spatial resolution technique will permit detailed analysis of normal and abnormal impulse conduction.
_
”
--
131 RYANODINE RECEPTORS IN NORMAL AND HYPERTROPHIED RAT HEARTS. V. Naudin, P. Oliviero and D. Charlemagne. INSERM, Ul27, Hopital Lariboisiere, 75010 Paris, France. During a pressure overioad induced rat cardiac hypertrophy. the action potential duration is prolonged, and the calcium transient and the time to peak tension are delayed. It has been shown that these modifications which are related to modifications in the excitationcontraction coupling neither originate from changes in the dihydropyridine receptors density or calcium current nor from alterations in myofibrillar calcium sensitivity. These modifications may, however, be related to changes in the Ca induced Ca release process and therefore to the ryanodine receptors.We compared the total number, density and affinity of ryanodine receptors between homogenates from normal and hypertophied left ventricles. Preliminary results of [3H]ryanodine binding indicate that the density of ryanodine receptors at a saturating concentration of ryanodine is similar in normal and hypertrophied hearts while the total number of receptors increases with hypertrophy. Further experiments will be performed on purified sarcoplasmic reticulum preparations to confirm these results from which we hope their relevance to excitation-contraction coupling can be delineated.
132
COMPIJTATION OF CARDIAC VENTRICULAR VOLUMES FROM ECHOCARDJOGRAPHIC IMAGES. M. Neveu, A. Dipanda, H. Diebold, L. Dusserre. Laboratoire d’Informatique Medicale, Hopital du Borage C.H.R.U. DE DT.JON, B.P. 1542 21034 DIJDN CEDEX, France. Computation of cardiac ventricular volumes from echocardiographic images has to and 3D positionning of the probe. To face two problems : bad quality of images, solve these two problems, we have elaborated a 3D model of the ventricles with BSplines functions, that is more precise than classical ventricular models. We have also elaborated a method to detect edges on echographic images, based on texture Automatically detected edges by this method analysis and cardiologists knowledge. and the cardiologists hand drawn edges are not significatively different. Modeledges matching allows the model distortion and ventr-icular volumes computation. On theoretical soli.ds, volume computation using this method is quite accurate : the error is less than 5%. In viva validation is soon expected on animals as well as comparisons with classical methods (angiography). S.44