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Biomedical subjects

P Chevalier

Publications and source records attributed to P Chevalier.

At least 91 records · Page 5Linked to original sources
PubMed1993

[Long-term results of implantable automatic defibrillator in 43 patients. Analysis of predictive factors of the first electric shock].

In order to identify patients who will receive an electric shock after implantation of an automatic fibrillator, the relationship between the time to the first shock and clinical and paraclinical characteristics were studied in 43 patients treated at the Lyon Cardiological Hospital between July 1987 and September 1991. The age of the patients was 49.5 +/- 16 years (mean + SD). Eighty two percent of patients were men and the average left ventricular ejection fraction was 38.5 +/- 16.8%. Four patients died in the peri-operative period. The average follow-up of the survivors was 22 months. During this period, 21 patients (53.8%) received an appropriate electric shock. Three patients died. The causal role of a malignant ventricular arrhythmia is discussed in one case. A second patient, who never had automatic fibrillation, died of cardiac failure. Finally, the third patient died of non-cardiac pathology. The 22 month actuarial survival rate was 86%. The probability of receiving an appropriate electric shock was 60%. Analysis of clinical and paraclinical features identified left ventricular dysfunction (ejection fraction less than 38%) and cardiac symptoms (Stage III dyspnoea of the NYHA classification) as being associated with earlier electric shocks. This association was even more clear cut in the group of patients with previous myocardial infarction. Therefore, patients with implantable automatic defibrillators for malignant ventricular arrhythmias receive appropriate electric shocks in over 50% of cases. Patients with symptoms of cardiac failure and low ejection fraction are particularly exposed especially when they have previous myocardial infarction.

Actuarial Analysis↗
PubMed1993

[Ablation of accessory pathways by radiofrequency current. Towards a simplified approach of Wolff-Parkinson-White syndrome?].

From December 1990 to April 1992, 41 consecutive patients (22 men and 19 women with an average age of 35 +/- 16 years -6-72) underwent ablation of accessory atrioventricular conduction pathways (Bundles of Kent) for poorly tolerated and/or medically resistant supraventricular tachycardias. In 33 cases, the arrhythmia was a paroxysmal SVT, in 7 cases atrial fibrillation, and in 1 patient incessant junctional tachycardia causing left ventricular dysfunction. The Wolff-Parkinson-White syndrome was apparent in 30 patients and concealed in 11 cases. The location of the Kent bundle was left lateral in 22 cases (53.7%), posterior paraseptal in 9 cases (21.9%), right lateral in 5 cases (12.2%) and anterior paraseptal in 5 cases (12.2%). The Kent bundles were ablated by radiofrequency currents in 38 cases (92.7%); in 2 patients (4.9%) in whom radiofrequency could not be used (increased impedance) high energy electrical shock was successful. In one patient (2.4%), it was not possible to suppress the Kent bundle. A single session of radiofrequency ablation was sufficient in 33 cases: 7 cases (17.5%) required 2 (4) or 3 (3) sessions. The average number of sites of application per patient was 8.8 +/- 8.8. The duration and intensity were respectively 32.2 +/- 9.3 (5-60) seconds and 25 +/- 15 (20-30) watts. With an average follow-up of tachycardia or of ventricular preexcitation have been observed in the 40 patients. In addition, in 36 patients, electrophysiological control studies confirmed the initial result with absence of any disturbance of nodohisian conduction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Prognosis and long-term development of arrhythmogenic dysplasia of the right ventricle].

The authors studied the clinical, angiographic and electrophysiological features, and the long-term outcome of patients with arrhythmogenic right ventricular dysplasia (ARVD). The study was retrospective and involved 22 patients (3 women and 19 men) with an average age of 36 years at the time of their first documented ventricular tachycardia (VT) and admitted to hospital between 1971 and 1989. The diagnosis of ARVD was based on the association of monomorphic VT with a left bundle branch block morphology and right ventricular abnormalities on angiography. Fifteen patients were treated by antiarrhythmic drugs alone, 5 by antiarrhythmic drugs and tachycardia ablation and 2 by antiarrhythmic drugs and cardiac transplantation. An automatic defibrillator was implanted in one patient. After the first episode of VT, the beginning of follow-up, the criteria of evaluation were mortality, right heart failure and the evolution of the arrhythmia. The study population had the following characteristics. Familial forms or ARVD were observed in 18%. The mitral ventricular arrhythmia was often induced by exercises (45%). Twenty-one patients had a sustained VT and 1 patient had non-sustained VT. The resting ECG in sinus rhythm was abnormal in all cases. Thirty-two different VT morphologies were recorded. The abnormalities of the right ventricular wall motion on ventriculography were localised in 45% of cases and diffuse in 55% of cases. Seventy per cent of patients undergoing electrophysiological investigation had inducible sustained VT. The clinical outcome after an average of 10.7 years' follow-up was: 17 survivors, 3 sudden deaths and 4 cases of right ventricular failure. The 10 year actuarial survival rate was 75%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Double mitral orifice. Apropos of a case].

The authors report a case of Double Mitral Orifice (DMO), existing in isolation and type 3 by the Floch Prigent classification. This rare anomaly is often associated with another congenital malformation, dominated by intra-atrio-ventricular defect. Two-dimensional echocardiography is the essential diagnostic factor. Hemodynamic consequences may be nil, but mitral insufficiency and/or stenosis may complicate this malformation. Treatment may be summarised as abstention, surgical repair or valve replacement, according to the severity of lesions.

Adult↗
PubMed1990

[Neurologic complications of cocaine abuse].

Cocaine is increasingly used by drug addicts. It is considered harmless, but numerous, varied and often serious complications due to its abuse have been published. Among these, neurological complications are in the forefront. They include generalized or partial epileptic seizures, ischaemic or haemorrhagic cerebral vascular accidents, visual loss caused by optic neuropathy or by retinal artery occlusion, headaches and exacerbation of tics. Infections of the central nervous system are possible via endocarditis or septicaemia of venous or nasal origin. Neurological disorders may also occur as a consequence of a major cardiovascular complication induced by cocaine (myocardial infarction and/or dysrhythmia, aortic dissection). These neurological complications are unpredictable, and they weigh heavily on the functional and sometimes vital prognosis in habitual or occasional cocaine abusers.

Adult↗
PubMed1990

Interaction of suriclone with central type benzodiazepine receptors in living baboons.

The interaction of suriclone and two of its main metabolites with central type benzodiazepine receptors, which had been labeled in vivo with the radioligand [11C]RO 15-1788, was investigated in living baboons. The concentration of radioligand bound to the receptors, as measured in brain transverse sections by positron emission tomography, decreased rapidly after the i.v. administration of suriclone at doses known to induce pharmacological effects. The rate and extent to which [11C]RO 15-1788 binding was displaced increased with increasing doses of suriclone. The half-inhibitory dose (ID50) was determined to be 0.08 mg/kg in vivo. The rapid inhibitory effect of suriclone on the in vivo binding of [11C]RO 15-1788 in the brain seems to reflect its ability to act at the GABA-benzodiazepine receptor complex, at or near to the benzodiazepine binding site, to induce its pharmacological activity. The i.v. injection of the demethylated metabolite of suriclone, RP 35,489, only caused a slight displacement of [11C]RO 15-1788 binding even at a dose of 2 mg/kg. Thus, suriclone appears to be more potent than RP 35,489 to displace the benzodiazepine 11C antagonist in vivo. The sulfoxide metabolite, RP 46,166, did not significantly change the kinetics of [11C]RO 15-1788 binding in the brain. The slight effects produced by high doses of RP 35,489 and RP 46,166 on [11C]RO 15-1788 binding in the brain suggest that these metabolites are probably not responsible for the expression of biological activity of suriclone mediated by benzodiazepine receptors.

Animals↗
PubMed1990

Sensitive radioimmunoassay and enzyme-linked immunosorbent assay for the simultaneous determination of chloroquine and its metabolites in biological fluids.

Two new methods for the simultaneous determination of chloroquine and its two main metabolites (monodesethylchloroquine and bisdesethylchloroquine) in biological samples, radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA), are described. Antiserum is produced in rabbits immunized with N-(2-carboxyethyl)desethylchloroquine:protein conjugate. Besides chloroquine, this antiserum recognizes with good affinity the two main metabolites, monodesethylchloroquine and bisdesethylchloroquine (70 and 40% of crossreaction, respectively). Amodiaquine cross reacts by 4.5%; cross reactions with monodesethylamodiaquine, bisdesethylamodiaquine, and other antimalarial drugs are less than 1%. No extraction step or sample preparation is required for either system. Sensitivity limits are, respectively, 0.70 nM (3 pg of chloroquine sulfate measured in 10 microL of plasma sample) for RIA, and 10 nM (22 pg of chloroquine sulfate measured in 5 microL of plasma sample) for ELISA. The interassay coefficients of variation are, respectively, less than 10 and less than 16% for RIA and ELISA in the range 14-410 nM (6-180 ng/mL). The results of both methods are well correlated (r = 0.97) and correlate with spectrophotometry (r = 0.98) and HPLC results (r = 0.93). Because of their high sensitivity, both methods can be used in the case of chloroquine poisoning and in the control of malaria prophylaxis and treatment.

Animals↗
PubMed1990

Detection of Bifidobacterium species by enzymatic methods.

The properties of Bifidobacterium strains of human origin were examined by three enzymic tests and the amounts of acetic and lactic acids produced were also quantified. It was evident that two strains of the American Type Culture Collection (ATCC) did not belong to the genus. Moreover, at least one strain of Bifidobacterium added to some milk preparations did not show distinctive characteristics of the genus. It was also shown that most of bifidobacteria studied produced alpha-galactosidase (EC 3.2.1.22) and alpha-glucosidase (EC 3.2.1.20). The presence of alpha-galactosidase could afford a rapid differentiation of bifidobacteria used in some dairy products since this enzyme was not detected in Lactobacillus strains studied.

Acetates↗
PubMed1990

[Magnetic resonance imaging in the diagnosis of pheochromocytoma].

The diagnosis of pheochromocytoma is biological. If ultrasound enables the visualization of certain adrenal tumours or hepatic metastasis, in fact two tests enable the topographic diagnosis, the screening of ectopic localizations and metastasis. They are IMBG scintigraphy and tomographic scanning. The place of magnetic resonance imaging is not yet specified. However, it has many advantages: absence of irradiations, good anatomic precision, meticulous screening of ectopic forms, of metastases and of adenopathies, study of the tissue characterization, good definition of the tumour relation with the vascular pedicles and the neighbouring structures.

Adrenal Gland Neoplasms↗
PubMed1989

[False and true hypertension in the aged subject. Diagnostic errors and potential solutions].

Arterial hypertension has the same definition in elderly people as in young adults. Epidemiologically, it has clearly been demonstrated that in the elderly it is a risk factor of morbidity and cardiovascular mortality. The international reference method for measuring blood pressure is by auscultation and mercury manometer. However, this indirect measurement is the source of many errors due to the material or the observer, or inherent in the method. A typical example of this is pseudohypertension in the elderly. Several solution are offered to improve the reliability of indirect blood pressure measurement, the most convincing one being the use of scientifically validated autonomous instruments relying on the oscillometry system. Ambulatory blood pressure measurement is interesting, being of diagnostic, therapeutic and probably prognostic value, but all this has to be confirmed in elderly subjects.

Aged↗
PubMed1989

[Bronchial cancer with extension into the heart. Apropos of a case with magnetic resonance imaging].

The authors report a case of a 64-year-old patient with an adenocarcinoma of the bronchus with mediastinal involvement. The echocardiography and CT scan showed the existence of involvement of the left auricle. Confirmation and the extent of the intra-cardiac involvement were provided by nuclear magnetic resonance imaging which confirmed the diagnosis here and was particularly helpful. The authors further recall that the place of nuclear magnetic resonance as a standard investigation in assessing staging in bronchial cancer remains to be determined in relation to CT scanning.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1989

[Spontaneous dissection of the renal artery].

In this paper we describe a case involving spontaneous dissection of the renal artery (DRA) successfully treated with an aorto-renal venous graft. DRA is a rare disorder which strikes men especially. Hypertension is the most frequent sign of its presence, which is usually of sudden onset, and with major adverse impact on the eye and brain. Arteriography is the key diagnostic examination. The most typical image is that of "cuffing". Treatment is surgical in nearly 50% of cases and should be as conservative as possible since these lesions may be bilateral.

Aortic Dissection↗
PubMed1989

[Mycotic aneurysms].

Mycotic aneurysms are aneurysms infected by bacteria or fungi. These may be secondary to an endocarditis, or they may be primary, and then are developed from a septicemia or bacteremia. The diagnosis, often difficult, is sometime only made during complications, the most severe of which is rupture. This diagnosis must be aided by new imaging techniques such as ultrasonography, tomodensitometry, magnetic resonance imaging. The treatment is medical (antibiotics) and surgical.

Adult↗
PubMed1989

[Experience at an Internal Medicine service in the postoperative follow-up of 403 patients operated on at a cardiovascular surgery service].

Over the last 3 years, 403 patients operated in the Department of Cardiovascular Surgery of Broussais Hospital have been transferred to a Department of Internal Medicine for secondary postoperative care. A total of 245 non-cardiac complications (64%) and 134 cardiac or vascular complications (36%) were observed in 321 of these 403 patients (80%). Infections accounted for 26% of non-cardiac complications (63/245). They included 9 cases of mediastinitis, 2 cases of septicemia, 6 endocarditis, 6 wound infections, and 40 other infections (ENT, gastrointestinal, pulmonary, urogenital). The non-cardiac, non-infectious complications comprised mainly delayed healing (39 cases) and pleuropulmonary (29 cases), ENT (9 cases), gastrointestinal (31 cases), urogenital (12 cases), hematological (17 cases) and neuropsychiatric (9 cases) complications; and, finally, 37 inflammatory syndromes. The cardiac complications were pericarditis with or without tamponade (24 cases), arrhythmias or conduction disturbances (50 cases), haemodynamic (54 cases) and vascular (6 cases complications. These very varied complications sometimes occurred late and could be latent. They resulted in prolongation of the duration of hospitalization, so increasing the overall health costs.

Cardiovascular Diseases↗