[en] Short communication
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[en] Published in summary form only
Journal
[en] The left ventricular asynchrony of both ejection and relaxation phases as also their interrelationship are analysed at rest after Dipyridamole (0.44 mg/kg) in 27 patients without previous myocardial infarction and with a normal ejection fraction at rest. The patients are divided in three groups: G0: 13 patients with no coronary artery disease (CAD), G1: 7 patients with one vessel disease and G2: 7 patients with two or three vessels disease. Two high temporal resolution sequential radionuclide ventriculographies are obtained at rest and after Dipyridamole (36 images in LAO projection). No significative variations were observed for the differences rest-Dipyridamole for the three groups and regarding the parameters derived from the global left ventricular time-activity curve: peak emptying and filling rates (PER and PFR) and their corresponding appearing times in the cardiac cycle (TPER and TPFR* = time to end systole + time to peak filling rate). New functional images representing the pixel by pixel distribution of the TPER and TPFR* are obtained, permitting the determination of the corresponding histograms. The relative variations rest-Dipyridamole of the full width at half maximum (dispersion) of the TPER histograms are different (p<0.01) between the control group G0 and the CAD patients (G1 + G2), contrary to the dispersion of the TPFR histograms. Moreover there is as linear correlation (r = 0.74, p<0.01) between the relative variations rest-Dipyridamole of the TPER versus TPFR dispersions of the CAD patients (G1 + G2). These findings suggest that the relaxation asynchrony in patients with CAD is a consequence of dysfunction of the ejection phase
[fr]
Les asynchronismes des phases d'ejection et de relaxation du ventricule gauche ainsi que leur interdependance sont analyses au repos et apres Dipyridamole (0,44 mg/kg) chez 27 patients sans antecedents d'infarctus du myocarde et dont la fraction d'ejection globale au repos est normale. Ils ont ete classes en trois groupes: G0: 13 patients sans atteinte coronaire, G1: 7 patients monotroculaires, G2: 7 patients bi ou tritronculaires. Deux ventriculographies isotopiques de haute resolution temporelle (36 images en OAG 400) sont realisees sequentiellement au repos et apres Dipyridamole. Aucune variation significative n'a ete demontree sur les differences repos-Dipyridamole et pour les trois groupes lorsque l'on analyse les parametres de la derivee globale de la courbe activite-temps: maximum du taux d'ejection (MTE) et de remplissage (MTR) et leurs temps d'apparition dans le cycle cardiaque (TMTE et TMTR). De nouvelles images fonctionnelles representant pixel par pixel les TMTE et TMTR ont permis le calcul des histogrammes correspondants. Nous montrons que les variations relatives repos-Dipyridamole des dispersions de l'histogramme des TMTE sont differentes (p<0,01) entre les patients G0 d'une part et G1 + G2 d'autre part alors que ce n'est pas le cas pour la dispersion de l'histogramme des TMTR. De plus chez les patients coronariens il existe une correlation (r = 0,74; p<0,01) entre la variation relative repos-Dipyridamole de la dispersion de l'histogramme des TMTE et celle de l'histogramme des TMTR. Ces resultats suggerent que l'asynchronisme de la relaxation chez les patients coronariens semble independant du nombre de vaisseaux atteints et qu'il est une consequence du dysfonctionnement de la phase d'ejectionJournal
[en] With a dedicated MRI system at 0.1 T for hand and wrist imaging, previously developed in our laboratory, we have obtained high resolution normal finger images. The images were obtained using emitter/receiver radio frequency solenoidal coils developed for the fingers. In a matrix format of 128 x 128 pixels and for slice thicknesses of 3 mm, the maximal spatial resolution achieved is at present 0.2 mm by pixel
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[en] To determine the relationship between serum levels of myosin heavy beta chains assessed by an IRMA technique and other radionuclide and enzymatic parameters in the evaluation of the size of myocardial infarction, we studied 22 patients with acute myocardial infarction. Blood samples taken daily between 1st to 13th day of evolution allow the determination of peak and integral of myosine release that showed a good correlation (p<0.01) with myocardial underperfusion score in T1-201 SPECT, left ventricular ejection fractions at 1st day and at the pre-discharge study, just as CPK peak. This new assay is an interesting mean to evaluate the size of myocardial infarction
[fr]
Dans le but d'evaluer la relation entre les taux seriques des chaines lourdes beta de la myosine obtenus par une methode IRMA et d'autres parametres isotopiques et enzymatiques visant a approcher la taille de l'infarctus du myocarde, nous avons etudie 22 patients admis pour une necrose myocardique en evolution. Un prelevement sanguin journalier entre J0 et J12 a permis la determination du pic et de l'integrale de relargage de la myosine serique qui se sont reveles bien correles (p<0,01) avec le defaut de perfusion myocardique calcule en tomoscintigraphie au T1-201, les fractions d'ejection ventriculaire gauche aux phases precoce (J1) et differee (J10 a J12) ainsi qu'avec le pic des CPK. Ce nouveau dosage constitue un outil interessant dans l'evaluation de la taille de l'infarctus du myocardeJournal
[en] Pressure-volume (PV) relationship is an important element to appreciate left ventricular (LV) function. We developed an instrumentation to obtain PV loops using a simultaneous acquisition of LV pressure values measured by an intraventricular pressure probe connected to an analog to digital converter board in a PC, and LV volume values obtained by a standard LAO gated blood pool radionuclide technique (32 images/cycle). Both acquisitions, obtained in the nuclear laboratory, were simultaneously triggered to the same ECG signal using acceptance window of ± 10% of mean RR interval. The LV end diastolic volume, measured by a consecutive blood pool GSPECT was used to normalize LAO volume curve. Overall procedure takes less than an hour and averages 400-800 cardiac cycles. In this paper, we present the technique, its feasibility in patients and reproducibility of data. We obtained 16 PV loops in 10 patients with various cardiac diseases. Good quality PV loops were obtained in 9/10 patients and a good reproducibility was observed in the 6 cases who underwent two consecutive measurements. In one case, pressure curve was artificially deaden. This economic methodology appears feasible, useful, and promising to explore LV function in clinical practice. (authors). 17 refs., 5 figs., 2 tabs
Journal
Medecine Nucleaire. Imagerie Fonctionelle et Metabolique; ISSN 0928-1258; 
; CODEN MNIMEX; v. 20(6); p. 400-407
; CODEN MNIMEX; v. 20(6); p. 400-407