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Biomedical subjects

J Fourny

Publications and source records attributed to J Fourny.

At least 19 recordsLinked to original sources
PubMed1997

Biomechanical characteristics of unconditioned and conditioned latissimus dorsi muscles used for cardiocirculatory assistance.

An understanding of the biomechanical characteristics of striated skeletal muscles involved in cardiocirculatory assistance is a prerequisite to assess their efficacy and to evaluate their haemodynamic benefits. Six goats had their latissimus dorsi muscles evaluated by isometric strain gauge testing. Total tension, and both active and passive force development at different preloads were measured. The relationship between muscle impedance and starting length was also studied. Four additional muscles were submitted to isometric and isotonic strain gauge testing after 3 months of chronic electrical stimulation (Broussais Hospital protocol) with the contralateral muscle serving as a control. In isometric testing, both conditioned and unconditioned goat latissimus dorsi displayed a Frank-Starling length-tension curve, and a linear relationship between muscle impedance and starting length was found. Chronic stimulation preserved muscle mass and isometric force. Transformed muscles showed a mean 59% reduction of maximal shortening velocity; means (s.d.) residual shortening velocity at maximal work and power output was 0.17(0.07) m/s. The work and power output were both reduced 65% after stimulation, and the residual maximal power at optimal preload varied from approximately 7.7 and 9.6 W/kg. It is concluded that, following the Broussais protocol, the goat latissimus dorsi muscle retained mass and most of its isometric force-generating capacity, but lost significant work and power potential. The residual power output did not, however, preclude the possibility of a significant cardiocirculatory contribution, providing that the conditions for optimal energy transduction are adequately delineated.

Animals↗
PubMed1995

Rhythmic and electrophysiological study after dynamic cardiomyoplasty.

To question the possible proarrhythmic effects of cardiomyoplasty (CMP), six adult goats were submitted to rhythmic and electrophysiological (EP) study 15 days before and 8 months after a posteroanterior clockwise CMP procedure using Medtronic Cardiomyostimulator (CMS) (SP1005) and electrodes (SP5528) and completion of a progressive stimulation protocol. Pre and postoperative screening included a surface ECG, 24-hour Holter monitoring, high amplitude and filtered QRS averaging, and invasive EP study performed in the postoperative period with the CMS "ON" and "OFF." One-hour Holter recording with desynchronization of the CMS was obtained. Comparison of pre and postoperative ECG and rhythmic data showed no significant difference. High amplitude QRS averaging did not evidence meeting the usual criteria of late potentials. EP values were stable in both conditions and the aggressive EP program did not show evidence of increased susceptibility to arrhythmias. Asynchronous cardiomyostimulation did not induce arrhythmias. Our data strongly suggest that provided meticulous surgical technique is used, CMP does not significantly interfere with the electrical characteristics of the normal goat heart. The procedure, despite the disturbances it provokes, does not seem to be arrhythmogenic. The function of the CMS was always appropriate, even under stressful EP conditions.

Animals↗
PubMed1992

[Cardiomyoplasty].

Explore the source record for details and available documents.

Adaptation, Physiological↗
PubMed1991

Influence of tension reduction and peripheral dissection on histologic, biochemical and bioenergetic profiles, and kinetics of skeletal muscle fast-to-slow transformation.

Seven goat latissimus dorsi muscles were submitted to a progressive electrostimulation program through intramuscular electrodes (Medtronic SP5528). Group 1 (n = 3) consisted of muscles stimulated in situ, and group 2 (n = 4), of muscles dissected distally and reinserted on the chest wall with a reduced tension. In group 1, complete fiber switch from type II to I occurred within 60-100 days after the beginning of stimulation, as demonstrated by myosin isoforms and lactate dehydrogenase (LDH) isozymes pattern. Respiratory chain oxidases first increased within 30-70 days after stimulation, then progressively decreased to stabilized values, higher than the basal ones. Total LDH activity showed progressive decrease to one-fifth of the initial value. Morphological analysis confirmed the structural integrity and physical reinforcement of the muscles. In group 2, respiratory chain oxidases showed initial increase followed first by a fast reduction to values less than the starting ones, and then by a slow secondary increase between day 40 and 90. LDH activity displayed a sharp decrease between day 15 and 36. Myosin as well as LDH isoforms showed progressive conversion. This kinetic study suggests a three-phase adaptative evolution of the goat latissimus dorsi submitted to increased workload (group 1): a fast increase (phase I) in oxidative capacities is followed by the development of an efficient contractile machinery (phase II), with subsequent adaptation (phase III) of the terminal chemosmotic enzymes involved in energy production.+2

Adaptation, Physiological↗
PubMed1989

Giant cell arteritis (Horton's disease) of the axillary artery--case reports.

The authors recently observed 2 elderly female patients with ischemic pain of the upper extremity as the first manifestation of giant cell arteritis. They presented with rest pain of both upper extremities and even gangrene of the thumb in 1 case. Subclavian and radial pulses were absent while peripheral pulses in the lower limbs were preserved. The angiography was so typical that the diagnosis of inflammatory arteritis was made, despite negative temporal artery biopsy. The patient with thumb gangrene was successfully operated on, the occlusive axillary lesions being bypassed by a long venous carotid humeral bypass graft. A biopsy of the axillary artery showed a granulomatous lymphoplasmocellular infiltration. A high-dose corticotherapy (24 mg daily) was begun in both cases, with dramatic improvements of general state, lowering of the erythrocyte sedimentation rate, and even reapparition of a reduced radial pulse in 1 patient. The authors discuss the incidence, symptoms, diagnosis, and treatment of systemic giant cell arteritis, with special attention to extracranial involvement. These case reports may broaden the knowledge of the diverse manifestations of giant cell arteritis and of its systemic character with widespread vascular involvement.

Aged↗
PubMed1985

Artificial circus movement tachycardias: incidence, mechanisms, and prevention.

In a group of 45 patients treated with Medtronic 7000 and 7100 pulse generators for sick sinus syndrome or second or third degree atrioventricular block, an atrial synchronous mode of pacing was programmed in 34 cases and spontaneously occurring artificial circus movement tachycardias (ACMTs) were observed in nine. An analysis of conditions of occurrence, triggering mechanisms and patterns of ACMT, is presented. Various modalities of prevention are discussed. They resulted in suppression of ACMT in five patients and decrease of incidence in a sixth; the three remaining subjects were managed by definitive reprogramming in the DVI mode. Our conclusion is that correct prevention of ACMT requires the use of dual chamber pulse generators with programmable atrial refractory periods. For patients in whom a unit has already been implanted, careful observation of the triggering mechanism and pattern of ACMT may help in determining the most suitable way to prevent and suppress the arrhythmia.

Adult↗
PubMed1983

[Serum activity of angiotensin converting enzyme during extracorporeal circulation in man].

Serum activity of angiotensin converting enzyme (ACE) were measured during extra-corporeal circulation in five patients undergoing aorto-coronary bypass surgery. We observed a significant decrease of serum ACE levels in the absence of pulmonary circulation, suggesting that in man the lungs were the major source of circulating ACE. An effective extra-pulmonary liberation of ACE could take place during cardiopulmonary bypass. The levels of serum ACE increased with pulmonary recirculation, but preoperative levels were not reached 24 h later.

Aged↗
PubMed1983

Natural evolution of atrioventricular conduction in patients with sick sinus syndrome treated by atrial demand pacing. A study of 26 cases.

The authors have followed up 26 patients with sinus node disease who were treated by atrial pacing. The follow-up duration varies between 10 months and 3 years. Assessment of A.V. conduction was performed repeatedly by atrial pacing at increasing rates. Nine patients showed a progressive, sometimes early, deterioration of their A.V. conduction system; five (19%) developed second degree A.V. block of Mobitz type I for pacing rates lower than 100 beats/min. In three of them, the pace-maker had to be replaced by a dual chamber stimulator. Deterioration of A.V. conduction seems to be more frequent in subjects with antecedents of myocardial infarction (4/5) than in others (5/21: p less than 0.05). Deterioration of A.V. conduction is not uncommon among patients with sinus node dysfunction, especially after myocardial infarction. This constitutes a serious limitation to the use of atrial pacing.

Adult↗
PubMed1983

[Implantation of a cardiac pacemaker in the octogenarian].

Thirteen centres, specialized in pacemakers and studying the implantation, brought together their material. Consequently, 785 patients living with a pacemaker (PM) were grouped. The average age at the time of the first implantation is 83,5 years old. The mortality of 7.5% as well as the morbidity of 16% lie very low. Nevertheless, their causes are discussed and compared to those resulting from other types of surgical pathologies on the octogenarian. It seems that the implantation of a PM, even on a person of 80 or older, is an efficient therapeutic gesture, benign and capable of normalizing the chances and quality of life on a long term basis.

Aged↗
PubMed1983

[Arterial thrombosis of the lower limb in patients over 80 years of age. Belgian multicentric experience concerning 802 patients].

This report concerns a joint study of fourteen centres about the treatment of arterial occlusion of the low extremity. Eight hundred and two patients older than 80 years have been studied during a period from 1 to 27 years. The operative mortality was 25.2%. There was no significant difference in mortality between emergency cases and those patients who were operated under elective conditions. Leg amputations are followed by a significant higher mortality than more conservative surgery such as arterial by-pass, sympathectomy or embolectomy. The most frequent cause of death was from cardiopulmonar origin (57%). The postoperative morbidity of cardiac, pulmonary, urinary or infectious origin was frequent (50%). Surgical complications in the true sence of the word are quite rare and their frequency is limited to 7%. The conclusion of this study is that conservative surgery such as reascularisation or sympathectomy is, whenever possible, to be preferred over amputation not only because of their lower mortality (13 to 19%) but also since they permit better revalidation of these elderly patients.

Aged↗
PubMed1980

Five years' experience with intraaortic balloon pumping. The changing of indications and the emergence of prognostic indices.

The authors report their experience with IABP during 5 years. 40 patients have been submitted to this procedure, 31 for spontaneous non-complicated myocardial infarction. Overall survival rate was poor in those non-surgical conditions (8/31); better outcome was obtained if IABP was applied earlier in the course of the infarction and if left ventricular filling was continuously assessed. Therefore, use of prognostic index (such as SWI/PWP) and monitoring of pulmonary wedge pressure is stressed. Incidence of sudden death is high among short term survivors 4 out 5 deaths in 8 short term survivors. Usefulness of IABP in preparation for surgery or/and as postsurgical support is evident in this series (5/7 successes) with the exception of patients who did not come off pump (2 cases) and for whom IABP was ineffective.

Assisted Circulation↗