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Biomedical subjects

C Leclercq

Publications and source records attributed to C Leclercq.

At least 91 records · Page 5Linked to original sources
PubMed1995

Hemodynamic importance of preserving the normal sequence of ventricular activation in permanent cardiac pacing.

Pacing the right ventricle in the apex profoundly modifies the sequence of activation and thus the sequence of contraction and relaxation of the left ventricle. To evaluate the relative importance of preserving normal ventricular activation sequence and optimal atrioventricular (AV) synchrony in permanent pacing, we compared the effects of three pacing modes: AAI, preserving both normal AV synchrony and normal activation sequence; DDD, with complete ventricular capture that preserves only AV synchrony; and VVI, disrupting both, at rest and during exercise. Hemodynamic and radionuclide studies were performed in 11 patients who had normal intrinsic conduction and who were implanted on a long-term basis with a DDDR pacemaker for isolated sinus node dysfunction. AAI versus DDD and VVI significantly increased cardiac output at rest (6.6 +/- 1.3 L/min vs 6 +/- 0.9 L/min vs 5 +/- 1 L/min; p < 0.01) and during exercise (13.5 +/- 2 L/min vs 12.1 +/- 2.2 L/min vs 14.4 +/- 2.1 L/min; p < 0.01). Pulmonary capillary wedge pressure was lowest with AAI (15.4 +/- 4.5 mm Hg), with an average reduction of 17% compared with DDD (19.6 +/- 5 mm Hg; p < 0.01) and of 30% compared with VVI (25.8 +/- 7 mm Hg; p < 0.01) during exercise. Identical benefits were observed for all other hemodynamic parameters: right atrial pressure, pulmonary artery pressure, left ventricular (LV) stroke work index, and systemic vascular resistances. LV ejection fraction was significantly higher in AAI than in DDD at rest (61% vs 58%, respectively; p < 0.05) and during exercise (65% vs 60%, respectively; p < 0.05). This improvement in LV systolic function resulted principally from the increase in septal ejection fraction. LV filling also was improved in AAI as demonstrated by a significant increase in peak filling rate at rest and during exercise. These data show the importance of preserving, whenever possible, not only normal AV synchrony but also normal ventricular activation sequence in permanent cardiac pacing.

Adult↗
PubMed1995

Early results of conventional versus two-portal endoscopic carpal tunnel release. A prospective study.

The authors compare in a prospective, randomized study the early outcome of carpal tunnel release using either a conventional palmar open release (n = 40) or a two-portal endoscopic release (n = 56). Both groups were similar. No statistically significant differences were found regarding pain, disappearing of paraesthesiae or time to return to work. However, better recovery of grip strength was observed in the endoscopic group at 1 and 3 months. No surgical complications were observed in either group.

Adult↗
PubMed1995

[Importance of atrioventricular synchrony in hypertrophic obstructive cardiomyopathy treated by cardiac pacing].

This study was undertaken to evaluate the effect of permanent dual-chamber cardiac pacing in hypertrophic obstructive cardiomyopathy resistant to medication, paying particular attention to atrioventricular synchrony. Sixteen patients, mean age 59 +/- 13 years (range 36 to 80 years) were divided into two groups after in initial catheter study performed under temporary VDD pacing between March 1990 and April 1993. In group I (n = 11), the gradient was decreased by more than 50% whereas in group II (n = 5), the gradient was unchanged or reduced by less than 50%. The reduction of the gradient was immediately significant in group I, the mean value falling from 104 +/- 33 mmHg (range 60 to 170 mmHg) to 25 +/- 13 mmHg (range 10 to 60 mmHg) (p < 0.0001). In group II, the gradient only decreased initially from 132 +/- 13 mmHg (range 120 to 150 mmHg) to 88 +/- 25 mmHg (range 50 to 130 mmHg) (p < 0.003) but improved atrioventricular synchrony, obtained secondarily either by pharmacological prolongation of the PR interval (association of betablocker and verapamil) or by ablation of the atrioventricular junction, improved the haemodynamic benefits. The residual gradient recorded on the 7th day was only 26 +/- 15 mmHg (range 10 to 50 mmHg) (p < 0.0001). The comparison of the two populations showed that the mean PR interval was shorter in group II (p < 0.016) and the mean value of the optimal AV Delay (the longest AV Delay with complete ventricular capture) was also lower (p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1995

Pheochromocytoma and secondary erythrocytosis: role of tumour erythropoietin secretion.

Certain neoplasias can induce unregulated erythropoietin (EPO) secretion which results in secondary erythrocytosis. Pheochromocytoma associated with erythrocytosis constitute a rare condition, where the secondary red cell abnormality is believed to be due to tumour EPO secretion. In one such case of pheochromocytoma related erythrocytosis, quantitative determination of serum EPO by enzyme immunoassay was combined with immunohistochemical examination of tumour tissue sections to locate the site of EPO secretion. EPO levels were initially high but decreased after tumour surgery, while immunolocalization showed EPO to be secreted by the neoplastic cells.

Adrenal Gland Neoplasms↗
PubMed1995

[The esophageal approach in rhythmology].

The possibility of detecting the electrical activity of the heart from the oesophageus has been recognised for nearly a century. On the other hand, transesophageal pacing has only been really developped in the last fifteen years, which explains the recent interest for this technique in clinical practice. Easily put into practice, but not always well tolerated, the oesophageal approach has many uses in rhythmology. The principal diagnostic applications are in unlabelled tachycardias whether with narrow or wide QRS complexes, the evaluation of the Wolff-Parkinson-White syndrome, the study of sinus node function or nodal conduction. The therapeutic applications are dominated by the reduction of supraventricular tachycardias especially atrial flutter, with a success rate similar to that of endocavitary stimulation. The facility of realisation, especially at the patient's bedside, without need for fluoroscopie control, makes it a useful tool in emergencies, especially if the endocavitary approach cannot be used. The only reserve is the painful character of pacing in some patients.

Anti-Arrhythmia Agents↗
PubMed1995

[Infections on permanent endocavitary pacemaker leads: value of transesophageal echocardiography].

The prevalence of infection of permanent pacing material ranges from 0.13 to 19.9% of patients according to published series. The seriousness of this condition requires early diagnosis and treatment. Transesophageal echocardiography visualised vegetations on the intracardiac pacing lead in all of 11 patients studied, whereas transthoracic echocardiography and polynuclear leucocyte scintigraphy only provided positive diagnoses in 4 cases for each investigation. Three types of vegetation were visualised; no cases of tricuspid valve endocarditis were observed. Treatment was based on explantation of all implanted material by endovascular traction in 7 cases and by surgery in the other 4 cases according to the results of transesophageal echocardiography. There were no deaths or recurrence of infection. Transesophageal echocardiography is the investigation of choice for imaging a vegetation on an endocavitary pacing lead. Complete explanation is essential for a complete recovery of this infection.

Adult↗
PubMed1994

[Permanent atrial resynchronization by synchronous bi-atrial pacing in the preventive treatment of atrial flutter associated with high degree interatrial block].

UNLABELLED: Interatrial conduction block results in a very delayed and retrograde activation of the left atrium and is associated with a high incidence of atrial tachyarrhythmias, especially a particular (and specific) form of atypical atrial flutter. Electrophysiologic studies have suggested that these arrhythmias were usually due to reentry and could be directly related to the conduction disturbances in the atrium. If so, we can expect reasonably that permanent atrial resynchronization resulting from simultaneous pacing in different target sites in the atria, may not only correct for interatrial dysynchrony, but also may significantly contribute to prevent arrhythmia recurrences. Twenty-eight patients, mean age 68 years, were included. The mean P wave duration in spontaneous sinus rhythm was 181 +/- 28 ms. In all patients, many recurrences of atrial tachyarrhythmia were documented, especially a specific form of atypical atrial flutter. Medical therapy was constantly ineffective. Three different pacing modes were used: 6 patients, with normal A-V conduction were implanted with a SSI device, programmed in AAT mode and connected, using a Y bifurcated connector, to two atrial leads, one positioned in the right atrium, the second one into the coronary sinus-in 14 patients, with A-V conduction defects, a conventional DDDR unit was implanted and connected to a composite biatrial electrode and a ventricular lead. In that configuration atrial resynchronization was only effective on paced atrial cycles -a specific DDD Chorus ELA Medical device with a special algorithm loaded into the RAM memory was implanted in 14 patients (8 new indications, and 6 patients first implanted with a DDDR unit). RESULTS: during sinus rhythm atrial resynchronization induced a reduction of the P wave duration from 181 +/- 28 ms to 116 +/- 12 ms. During permanent pacing the mean value decreased from 209 +/- 38 ms to 108 +/- 13 ms. During follow-up (34 +/- 15 months) arrhythmia prevention was assessed by history, by monthly surface ECG's and by bimonthly 24 hours Holters recordings and telemetric interrogation of the pacemaker statistics. Twenty-one patients did not experienced any recurrence of arrhythmia. One to three recurrences occurred in the other seven patients, including six patients implanted with a conventional DDDR unit. These preliminary results seem validate the new concept of atrial resynchronization for prevention of atrial arrhythmia associated with interatrial conduction block.

Adult↗
PubMed1993

Clinical role of d-sotalol and d,l-sotalol in supraventricular arrhythmias, including pre-excitation.

Numerous trials performed over the last 20 years, although uncontrolled, have shown the racemic d,l-sotalol is effective for the acute conversion and for long-term prevention of recurrences of supraventricular tachyarrhythmias. Sotalol appeared to be moderately effective in atrial fibrillation or atrial flutter, having somewhat greater efficacy in the case of atrioventricular (AV) nodal re-entrant tachycardia due to Wolff-Parkinson-White syndrome or concealed accessory pathway. These effects may stem from the combined class II and class III electrophysiologic properties of this drug. However, studies comparing d,l-sotalol to pure beta blockers in different 'models', especially postsurgical arrhythmias and Wolff-Parkinson-White syndrome, have suggested that the observed clinical benefit may be related to d,l-sotalol's class III properties. Thus, d-sotalol may be efficacious in these indications. Its precise efficacy should be defined in controlled clinical trials.

Adrenergic beta-Antagonists↗
PubMed1993

[Diagnostic and therapeutic strategy in coronary insufficiency in the elderly. Apropos of 65 cases].

As people live longer, so cardiologists are having to manage coronary artery disease in progressively older patients with more severe coronary lesions. The authors tried to determine the feasibility and results of coronary angiography in a retrospective study of 65 patients (44 men and 21 women) over 75 years of age (range 75 to 84 years) with coronary artery disease (excluding valvular heart disease). The study period was 22 months. The commonest indication was unstable or invalidating angina resistant to medical therapy (42 of the 65 cases). Twenty-two patients underwent coronary angiography in the context of myocardial infarction complicated in 3 cases by septal rupture. With the exception of these 3 patients, two of whom underwent surgery, 39 of the 62 remaining patients were judged to be candidates for myocardial revascularisation (63%); 37 underwent a revascularisation procedure (60%), 20 by percutaneous transluminal coronary angioplasty and 17 by coronary bypass surgery. The primary success rate of angioplasty was 90% (18 out of 20). There were no deaths in this group. Two patients who were referred for surgery died, an operative mortality of 12% (2 out of 17). All patients were followed up: 56 out of the 65 were still alive at the time of enquiry, after an average period of 18 months. All surviving patients who were successfully revascularised (by angioplasty or surgery) were pauci- or asymptomatic. Although there is an increased mortality related to revascularisation of elderly patients, this would seem to be acceptable given the quality of the medium term clinical results.

Aged↗
PubMed1993

[Radiofrequency catheter ablation of accessory atrioventricular pathways: initial experience in 33 patients].

The authors report their experience in endocavitary radio-frequency ablation of 37 secondary pathways carried out in 33 consecutive patients. The indications for radical treatment were based solely on clinical arguments in 15 patients, on a combination of disabling signs and threatening electrophysiological signs in 17 patients and on high retrograde permeability in 1 asymptomatic patient. Endocavitary exploration revealed 26 left lateral sites, 7 posterior paraseptal sites and 4 right lateral sites. The procedure was successful in 88% of cases. Electrophysiological follow-up, carried out routinely in all the patients 2 months after the procedure, revealed a single recurrence (3%) which was treated by radio-frequency again, this time with a successful outcome. There was only one complication, a complete AVBBB following ablation of a left posterior paraseptal Kent's bundle, which required a permanent pacemaker. These results were similar to those reported in the literature and clearly demonstrate the efficacy of radio-frequency treatment of the secondary pathways, with a moderate risk of complication. These results were similar to those reported in the literature and clearly demonstrate the efficacy of radio-frequency treatment of the secondary pathways, with a moderate risk of complication. Recent advances in the field of endocavitary ablation have made it possible to change the method of handling symptomatic Wolff-Parkinson White syndromes, by enlarging the indications for radical treatment in order to enhance the comfort and quality of life of the patient.

Adolescent↗
PubMed1992

[Results of coronary-angiographic evaluation after endocavitary fulguration of the accessory pathways].

Left ventricular aid coronary angiography was performed systematically in 32 consecutive patients (average age 34 +/- 16 years) to assess the potential risk of coronary and myocardial lesions after high energy catheter ablation of an accessory pathway. The control was performed 2 to 6 months after the procedure in 30 patients and as an emergency immediately after the procedure in 2 patients because of prolonged ST segment elevation in 1 and an echocardiographic abnormality in the other. The catheter ablation was performed by a right heart approach in 19 patients and by retrograde catheterisation of the left heart in the other 13. The average number of shocks delivered was 3.6 +/- 2.4 in 1.8 +/- 1.2 session with an average energy of 632 +/- 220 joules. The global success rate was 88%, 70% complete successes and 18% clinical successes. The left ventricular and coronary angiographies were normal in 31 patients, including the 2 patients investigated as an emergency. On the other hand, one totally asymptomatic patient in whom a left lateral bundle of Kent had been ablated 2 months previously by a retrograde transaortic approach, had a large pseudo-aneurysm of the left ventricular posterior wall and coronary angiography showed a fistula between the first lateral branch of the circumflex artery and the left ventricle. At surgery, a localised rupture of the mitral annulus was confirmed. Two factors may at least partially explain this complication: the quantity of energy delivered (1,000 joules) in a single session to a limited area, and the site of ablation on the ventricular side of the mitral annulus.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Remodeling of the heart (membrane proteins and collagen) in hypertensive cardiopathy.

The basis for impaired left ventricular function of hearts in moderate to severe stages of hypertrophy and congestive heart failure remains uncertain. At the cellular level, the mechanisms governing the movements of calcium in the myocardium are actually depressed and might at least in part account for the slowing of the maximum shortening velocity and the impaired relaxation. These alterations of membrane proteins seem particularly important in species where the slowing of Vmax cannot be a consequence of the myosin heavy chain shift. They lead to an unstable equilibrium of calcium homeostasis and to calcium overload in heart failure. On the other hand, the enhanced density and remodeling of collagen in the hypertrophied heart, which would depend on elevation in circulating aldosterone, impair myocardial stiffness with diastolic dysfunction and lead to altered pumping capacity of the heart. Disturbances of calcium metabolism and matrix collagen remodeling enhance early afterdepolarizations and arrhythmias.

Animals↗
PubMed1992

[Value of an algorithm of automatic adaptation of the atrio-ventricular delay to the instantaneous atrial rate in cardiac stimulation].

It has been suggested that an algorithm of automatic adaptation of the AV delay to the instantaneous atrial rate be introduced into the program of DDD pacemakers to reproduce the physiological adaptation of the PR interval to effort, characterised by progressive shortening inversely linearly related to the heart rate. In order to evaluate the potential benefits in conditions of "standard" programming (basal AV delay the same for all patients: maximal frequency of 1/1 AV synchronisation uniformly limited to 120 bpm), a haemodynamic study was undertaken in 10 patients who had permanent DDD pacemakers implanted for advanced AV block. Measurements were taken during two standardized exercise stress tests (20 W/2 mn steps from an initial load of 20 W) performed in a random order, one with a fixed AV delay of 156 ms and the other with an "automatic AV delay" allowing linear reduction from a maximum value of 156 ms at rest to a minimum value of 84 ms at the maximum heart rate of 120 bpm. At the peak of exercise the "automatic AV delay" significantly affected 4 parameters: the paced ventricular rate (p = 0.008) and rate-pressure product (p = 0.005) which increased, pulmonary capillary pressure (p = 0.03) and cycle-to-cycle variability of systolic and diastolic blood pressures (p = 0.02 < p < 0.0001) which decreased. There was a tendency (NS) to slowing of the spontaneous atrial rate and to increase in cardiac output. This increase was significant in some patients and seemed to be due to a good relationship between the individual optimal value of the value basal AV delay measured by Doppler echocardiography and the value programmed in this study (156 ms).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Spontaneous ruptures of the extensor tendons of the fingers in Madelung's deformity.

Madelung's deformity is a congenital malformation with a slow clinical and radiological evolution and few complications. However, we have seen six instances of spontaneous rupture of the extensor tendons of the fingers related to the deformity of the inferior radio-ulnar joint. Treatment consisted of resection of the ulnar head, stabilisation of the distal ulna, and repair of the extensor tendons by tendon transfers. We discuss the possibility of avoiding the tendon ruptures by treating the deformity at an early stage.

Aged↗
PubMed1991

[Use of propofol in 1350 anesthetized patients for electroconvulsive therapy].

Propofol was used for 1,350 sessions of electro-convulsive therapy (ECT). After 0.5 mg of intravenous atropine, patients received 1 to 1.5 mg.kg-1 bolus of propofol over a period of 20 seconds or less. This was convenient for loss of the eye-lash reflex. A bolus of 15 to 20 mg suxamethonium was given, in non allergic patients, to prevent trauma from the seizure. The patient was hyperventilated with pure oxygen through a facial mask. The electric shock was delivered bitemporally after a dental protection had been inserted. For each patient, the following data were noted: sex, use of tricyclic antidepressant drugs, atopy, amount of administered propofol and the effective intensity of the electric shock. The 99 patients were given 16.27 +/- 14 ECT sessions. Among them 26 took antidepressant drugs and 34 were atopic. There was no difference, except for weight, between the 25 men and 74 women. The mean dose of propofol was 1.37 +/- 0.3 mg.kg-1. The dose decreased with increasing age. There was no statistical relationship between the amount of propofol and intensity of the electric shock required to set off a seizure. The use of antidepressant drugs, and atopy did not influence the required amount of propofol. Speed of injection seemed to be the determining factor for narcosis with low doses of propofol. Hyperoxia and hypocapnia induced by hyperventilating with pure oxygen seemed to facilitate occurrence and duration of seizures. Although propofol has been said to reduce the length of seizures, there is controversy concerning the ECT efficacy criteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Palmar subluxation of the carpus in rheumatoid disease: a radiological evaluation.

The authors present a radiological assessment of palmar subluxation of the carpus in rheumatoid disease. The radiological measurements have been taken with reference to the long axis of the radius, the radiological centres of the lunate and the capitate and expressing their reciprocal distances as a ratio which we have termed the radio-carpal and inter-carpal indices. Using a control group of a 100 serial radiographs of normal wrists it was possible to determine the normal indices and their normal range. A subsequent analysis of 100 rheumatoid wrists enabled them to accurately determine the degree of anterior carpal subluxation, and allowed this form of radio-carpal malalignment to be differentiated from other forms of carpal instability.

Adult↗