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Biomedical subjects

J M Dupuis

Publications and source records attributed to J M Dupuis.

34 records · Page 2Linked to original sources
PubMed1997

Body composition and physical performance in children after renal transplantation.

Body composition using standard anthropometric methods and dual-energy X-ray absorptiometry (DEXA) was determined in a cross-sectional study among 26 pediatric renal transplant recipients. At the same time, spiroergometry exam, pulmonary function tests, dynamometry and tremometry exams were performed in all patients. Fat body mass obtained by DEXA correlated inversely with maximal physical load during spiroergometry exam (r2 = 0.51, p = 0.0001). The study demonstrates good tolerance of increased physical load in children after renal transplantation. An inverse relationship was found between fat body mass and physical performance. Exercise training programs for children after renal transplantation are therefore suggested.

Absorptiometry, Photon↗
PubMed1997

[Results of radiofrequency ablation of the atrioventricular junction in patients with refractory atrial arrhythmia and severe impairment of the left ventricular systolic function].

Results of radiofrequency ablation of the atrioventricular junction on functional capacity and left ventricular systolic function were assessed in 8 patients (aged 68 +/- 12 years) with refractory atrial fibrillation and severe left ventricular dysfunction, the mean ejection fraction being 31 +/- 11% (range: 20-48%). A clinical, echocardiographic and angioscintigraphic follow-up was performed 24 hours (basal), 3 and 6 months after the procedure. During follow-up, all patients reported the disappearance of palpitations and tiredness, a significant and early regression of effort dyspnoea from average NYHA Class 3.4 +/- 0.7 to 2.2 +/- 0.4 (M3), (p < 0.01), a decrease in end diastolic echocardiographic dimensions (from 57 +/- 10 to 52 +/- 9 mm (M3); p < 0.05) resulting in an increase in fractional shortening from 26 +/- 7% to 34 +/- 6%; p < 0.05. The isotopic EF increased from 31 +/- 11% to 42 +/- 12% (M3) (p < 0.01), and attained 48 +/- 12% (M6). This study shows that controlling the frequency and regularity of cardiac rhythm by ablation of the atrioventricular junction in patients with refractory AF and left ventricular dysfunction results in functional and haemodynamic improvement, especially when there is no apparent underlying cardiac disease. This suggests that this method should be proposed in all patients with refractory atrial fibrillation and left ventricular dysfunction.

Aged↗
PubMed1996

Accuracy and mean duration of different protocols of head-up tilt testing.

Based on the results of our study, > 95% of patients with a positive passive tilt test are also positive during 3 micrograms/min, and especially 5 micrograms/min, isoproterenol tilt test. A proposed time-saving protocol would be to initiate the test with an isoproterenol infusion and to perform a 45-minute passive tilt only in those patients with a positive 5 micrograms/min (an infusion rate reported to have an excessive low specificity) isoproterenol tilt test, and to consider only those with symptoms associated with objective changes during this latter test as "finally positive." An alternative option would be to perform a 45-minute passive tilt only in those patients with a negative 3 micrograms/min isoproterenol tilt test.

Adolescent↗
PubMed1996

Identification and expression of water stress- and abscisic acid-regulated genes in a drought-tolerant sunflower genotype.

We have studied two lines of sunflower (Helianthus annuus L.) selected in the field as drought-tolerant (R1 genotype) or drought-sensitive (S1 genotype). When subjected to drought conditions, the R1 line was able to maintain high leaf water potential longer and wilted later than the S1 line. Therefore, this indicates that R1 tolerance includes a leaf-adaptive response. By subtractive hybridization, we have isolated six different cDNAs (designated sdi for sunflower drought-induced) corresponding to transcripts accumulated in R1 and S1 leaves during adaptive response. Analysis of transcript accumulation in response to drought in both genotypes suggests a preferential expression of three sdi genes in the tolerant line. Abscisic acid-mediated induction, analysed in R1 leaves, was observed for only four sdi genes. Sequence analysis of six sdi clones revealed that five clones were related to known proteins including non specific lipid transfer proteins (nsLTP), early light-induced proteins (ELIP), l-aminocyclopropane-l-carboxylate oxidase (ACC oxidase) or dehydrins, predicted to be involved in a wide range of physiological processes.

Abscisic Acid↗
PubMed1996

[Value of thyroidectomy in amiodarone-induced hyperthyroidism. Apropos of 3 cases].

Amiodarone-induced hyperthyroidism in a relatively rare complication of long-term treatment with this molecule. It usually carries a good prognosis with regression being the rule after withdrawal of the drug although lethal forms have been reported. Conventional medical therapy (synthetic antithyroid drugs, steroids, betablockers) used in severe forms, is not always effective. In addition, amiodarone may be essential for the treatment of life-threatening, poorly tolerated arrhythmias, refractory to other forms of treatment. The authors report the cases of three patients treated with amiodarone for malignant arrhythmias who developed severe hyperthyroidism resistant to medical therapy and who were treated by total thyroidectomy. Surgery was followed by rapid resolution of the thyrotoxicosis without significant complications and immediate represcription of amiodarone. Thyroidectomy therefore seems a simple solution for amiodarone-induced hyperthyroidism allowing very rapid resolution of the hyperthyroidism and the possibility of immediate represcription of amiodarone.

Adult↗
PubMed1996

[Is the presence of right ventricular high intensity signals sufficient for the diagnosis of right ventricular dysplasia?].

The aim of this study was to assess "morphological" MRI data (spin-echo) compared with cine-MRI in 10 patients with documented right ventricular dysplasia and 10 normal controls. Data was acquired with a 0.5 Tesla superconductor magnet associating sequences of spin-echo and gradient echo (cine-MRI). An abnormal high intensity signal was observed in spin-echo in 9 out of the 10 patients. They were present on the anterior and sub-tricuspid walls of the right ventricle (8/10) and in the pulmonary infundibulum (8/10). A dyskinetic zone corresponding to the abnormal signals was detected in 8 patients. In the control group, only one subject had an abnormal high intensity signal and no dyskinesis could be detected. The association of high intensity signals and dyskinesis would seem to be very specific of right ventricular dysplasia. On the other hand, a high intensity signal alone may be observed in apparently normal subjects and would seem to be less specific.

Aged↗
PubMed1995

[Electrophysiological study for the diagnosis and prognosis of syncope of unknown origin].

OBJECTIVE: To evaluate, on the basis of long-term outcome, the value of electrophysiologic exploration for determining the cause of syncope of unknown origin after clinical examination and standard laboratory tests. METHODS: In 1985 and 1986, 109 consecutive patients with syncope of unknown origin underwent electrophysiologic exploration. The patients were divided into two groups. Baseline electrocardiogram was abnormal in 59 patients: cardiopathy (32%), ischemia (17%). In 44 of these patients, electrophysiologic exploration revealed major abnormalities requiring treatment (Group 1). No aetiology could be defined in 65 patients (Group 2). Patients were followed for 37 +/- 11 months. Three were lost to follow-up and 106 were retained for analysis. RESULTS: Morbidity and mortality were 25% and 16% respectively at the end of follow-up. Two sudden deaths were recorded, both in Group 1. Total mortality was greater in Group 1 (10 vs 6) so electrophysiologic exploration had defined a population at lower risk of sudden death and overall mortality. Relapse of syncope was observed in 27 patients (25% and 26% in Groups 1 and 2 respectively) due to rhythm disorders in 8, vasodepression in 1 and unknown origin in 18. CONCLUSION: The rate of recurrent syncope suggests these patients should have a second work-up in order to diagnose initially false negatives. Relapse raises the problem of electrophysiologic abnormalities and multifactorial mechanisms causing syncope of unknown origin.

Adult↗
PubMed1994

[Value of magnetic resonance imaging in cardiac sarcoidosis. Apropos of a case].

The authors report the value of magnetic resonance imaging (MRI) in a case of cardiac sarcoidosis presenting with syncopal ventricular tachycardia (VT). The images were acquired in a monomorphic multiplane echo spin sequence. A 25 millisecond interval was chosen for the weighted T1 sequence. A second weighted T2 sequence using an interval of 70 milliseconds was then performed. The acquisitions were recorded in these planes axial, sagittal and coronal. The thickness of the sections was 8 mm. MRI was useful in locating the exact site and extent of the lesions; this enabled the operators to perform "guided" endomyocardial biopsies. In the weighted T1 sequences, these biopsies showed zones of increased intramyocardial signal density, more pronounced on the second weighted T2 sequences. Moreover, it was possible to follow up the outcome of these lesions with steroid therapy and observe their partial regression. These non-specific appearances may be observed in all inflammatory conditions but, in the context of systemic sarcoidosis, are very suggestive of cardiac involvement. In view of the clinical latency of cardiac sarcoidosis and its poor prognosis, the non-invasive character of MRI should make this a routine investigation in all patients with systemic sarcoidosis.

Adult↗
PubMed1994

[Tachycardia with wide QRS. Limitations of electrocardiographic criteria in patients treated with anti-arrhythmia agents].

The diagnosis of ventricular tachycardia is difficult, often requiring endocavitary investigation to obtain proof. Many authors have attempted to define criteria used to distinguish between ventricular tachycardia and supraventricular tachycardia with wide QRS in the surface electrocardiogram. These criteria have been determined in patients not taking antiarrhythmic drugs. The authors report the case of a patient treated with flecainide for atrial fibrillation and hospitalised because of faints and tachycardia with wide complexes. The diagnosis of ventricular tachycardia was justified by surface electrocardiogram but was eliminated by subsequent endocavitary electrophysiological studies. The use of anti-arrhythmic drugs thus limits the applicability of electrocardiographic criteria in cases of tachycardia with wide QRS.

Anti-Arrhythmia Agents↗
PubMed1993

[Congenital hypoplasia of the left pulmonary artery and exertion hypoxemia].

The reported case concerns a 12-year-old boy with a congenital hypoplasia of the left pulmonary artery without associated cardiac malformation. At rest, pulmonary function tests were within the normal range, while the patient demonstrated an abnormal dyspnea and hypoxemia during exercise. These symptoms disappeared after left pneumonectomy. Unilateral pulmonary artery hypoplasia can be responsible for exercise hypoxemia due to an intermittent right-to-left shunt or a ventilation-to-perfusion mismatching.

Child↗
PubMed1993

[Thallium 201 myocardial scintigraphy and left branch block. Comparative value of exercise test and dipyridamole test].

Stress Thallium 201 myocardial scintigraphy in patients with left bundle branch block often shows reversible septal perfusion defects even in the absence of coronary artery disease. This phenomenon seems more common when the patients have tachycardia. With the working hypothesis that dipyridamole stress testing, which does not greatly increase the heart rate, would be more appropriate than exercise stress testing to unmask coronary artery disease in this condition, the authors compared the results of two Thallium 201 scintigraphies performed after exercise and then after dipyridamole under the same conditions three weeks later, in 67 patients with complete left bundle branch block. Scintigraphy showed one or more reversible perfusion defects in 64/67 patients after exercise but only 32/67 patients after dipyridamole (p < 0.001). There was poor uptake in the septal region in 59 patients (88%) after exercise and in 25 patients (37%) after dipyridamole (p < 0.001). The specificity was evaluated in 23 patients estimated to have no coronary artery disease. If only unequi vocal perfusion defects were considered, the specificity after dipyridamole was higher than that after exercise, increasing from: 35% to 83% for septal defects (p < 0.01); 65% to 96% for anterior wall defects (p < 0.05); 61% to 87% for inferior wall defects (p < 0.05); 57% to 91% for apical defects (p < 0.01); 17% to 83% overall (p < 0.001). Lower values but with a comparable difference were observed when all forms of hypofixation (even minimal) were taken into account.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Circulatory changes of the middle cerebral artery during syncopes produced by the head-up tilt test].

Velocity of the middle cerebral artery was recorded with transcranial pulsed doppler in 10 neurally-mediated syncopes elicited by 60 degrees head-up tilt test. Mean arterial blood pressure decreased by -36 +/- 16 percent (P < 0.0001) and heart rate by -6 +/- 27 percent (P < 0.05). Mean middle cerebral artery velocity decreased by -48 +/- 16 percent (P < 0.0001); Pourcelot's resistance index increased by 74 +/- 47 percent (P < 0.0001) and Gosling's pulsatility index by 218 +/- 111 percent (P < 0.0001). However, resistance normalized with mean arterial pressure showed no significant increase (+ 14 +/- 28 percent; NS). The decrease in diastolic velocity as well as mean arterial blood pressure and heart rate was significantly lower when loss of consciousness occurred. Contrary to those of other authors, our results do not support the hypothesis that syncopes result from a paradoxical cerebral vasoconstriction since no significant changes were observed in resistance normalized with mean arterial pressure. Thus, decrease in cerebral perfusion is likely to be the result of a decrease in cerebral perfusion pressure.

Adult↗