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Biomedical subjects

J Clementy

Publications and source records attributed to J Clementy.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Fulguration of accessory pathways in children. Value of two-dimensional echocardiography].

Six children (4 boys and 2 girls) aged from 3 to 7 years who had an accessory pathway and were suffering from paroxysmal (n = 4) or permanent (n = 2) refractory reciprocating tachycardia underwent transcatheter ablation of the accessory pathway alone in 5 cases and of the normal and accessory pathways in 1 case. Conduction in the accessory pathway was interrupted in 3 cases and sufficiently modified in 2 cases for the attacks of tachycardia to be suppressed by a simple and previously ineffective medical treatment. There was one failure. The authors underline the value of two-dimensional echocardiography in such cases. This technique is useful in the preoperative evaluation, during catheter insertion, and also in the choice of the electrodes to be used, for the ablation itself and in the search for postoperative lesions. Transcatheter ablation seems to be feasible and safe enough to be offered as an alternative to surgery in the treatment of refractory reciprocating tachycardia in children.

Adolescent↗
PubMed1989

[Electrophysiologic effects of intravenous 3-hydroxy-dihydroquinidine (LNC-834) in man].

The object of this study was to determine the electrophysiological effects of 3-hydroxy-dihydroquinidine (3-OH-HQ) in man. The electrophysiological parameters were measured in 12 patients before and after intravenous infusion of 5 mg/kg of 3-OH-HQ in 15 minutes. The mean plasma concentrations obtained varied from 2.4 +/- 1.1 mg/l at the 20th minute to 0.9 +/- 0.3 mg/l at the 60th minute. In these concentrations, 3-OH-HQ did not cause hypotension or affect the heart rate and nodal conduction. It did, however, prolong infra-hisian and intraventricular conduction and ventricular repolarisation from the 20th to the 60th minute after starting the infusion. The peak effect was observed at the 20th minute (+19 +/- 3.4 ms; +14.6 +/- 3.5 ms; and +44.5 +/- 6.6 ms, respectively). The 3-OH-HQ increased the effective atrial and ventricular refractory periods at the 30th minute (+21.8 +/- 5.5 ms and +22.3 +/- 7 ms, respectively). However, the ventricular effect only was discernable at the 60th minute. These effects are quantitatively comparable to those of quinidine. Extrapolation of these results to the effects of chronic oral treatment should be reserved as the therapeutic zone of this new molecule has not yet been determined.

Aged↗
PubMed1988

Left ventricular hypertrophy and ventricular dysrhythmic risk in hypertensive patients: evaluation by programmed electrical stimulation.

Left ventricular hypertrophy in hypertensive patients is associated with an increased prevalence of ventricular arrhythmias. Twelve patients with left ventricular hypertrophy assessed by M-mode echocardiography and 12 without left ventricular hypertrophy underwent an electrophysiological study with programmed electrical stimulation. The patients with left ventricular hypertrophy had a prolonged infranodal conduction time which correlated closely with left ventricular mass (r = 0.71; P less than 0.001). Programmed electrical stimulation initiated more intraventricular re-entry and unsustained ventricular tachycardia in the group with left ventricular hypertrophy than in the control group, although sustained ventricular tachycardia was never induced. We conclude that ventricular vulnerability is increased in hypertensive patients with left ventricular hypertrophy, especially in those who show electrocardiographic evidence of left ventricular hypertrophy.

Arrhythmias, Cardiac↗
PubMed1988

Long-term follow-up of atrioventricular junctional transcatheter electrical ablation.

Complete data concerning long-term results of transcatheter electrical ablation of the atrioventricular junction is not available. At the request of the French Cardiac Arrhythmia Working group we undertook an inquiry in October 1983. All centers potentially able to perform such procedures were asked to report their experience. Eight centers have performed one case or more, over a period of 3 years, for a total of 91 patients. The mean follow-up completed in all patients in April 1986 was 12 +/- 10 months. The procedure was indicated for a supraventricular arrhythmia resistant to a mean of 3.9 +/- 1.3 classes of antiarrhythmic agents. Atrial flutter or fibrillation in 54 (59%) and atrioventricular nodal reentry in 17 (18%) were the most common arrhythmias. A mean of 2.6 +/- 2.3 electrical shocks (range 1-14 shocks) with a stored energy of 130-400 joules was delivered during 1-5 sessions. Complete heart block was obtained in 83 patients and persisted at the time of discharge from the hospital in 46 patients (50.5%). The immediate complication (within 24 hours after the procedure) included ventricular fibrillation successfully converted (one patient) and nonsustained ventricular tachycardia (three patients). Late complications included one death 3 days after the procedure, in a patient in whom sustained ventricular tachycardia was documented, nonsustained ventricular tachycardia in two patients, sepsis in three patients and pericardial effusion in one patient. At the time of the follow-up, there were three additional deaths related to sepsis due to pacemaker pocket infection in one patient and to preexisting congestive heart failure in two patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Ablation of atrio-ventricular conduction by fulguration of the His bundle. Proposal for a simplified technic. Apropos of 70 cases].

Between 1982 and 1987, 70 patients (32 men, 38 women, aged from 45 to 93 years) underwent catheter ablation of His bundle and were followed up for more than 3 months. The disorders treated were atrial fibrillation, flutter of tachycardia (62 cases), junctional tachycardia (7 cases) and refractory atrial extrasystoles (1 case). The overall results were: early failure in 1 case, late death in 3 cases, persistent high degree AV block in 53 cases (75 p. 100), 1st degree AV block in 9 cases (12 p. 100) and failure in 8 cases (13 p. 100). Two techniques were used. In the first 30 patients ablation was performed by tri- or quadripolar catheters with electrodes 10 mm apart (USCI 2943/2854) and localization by an unipolar electrode connected to the negative pole of the defibrillator. The mid-term results in this series were: complete AV block in 20 cases (66 p. 100), partial AV block in 5 cases (17 p. 100) and failure in 17 cases (17 p. 100). In the last 40 patients localization was bipolar and ablation was obtained with simultaneous bipolar leads taken from a Josephson catheter with electrodes 5 mm apart (USCI 8567); the two electrodes recording the highest His bundle potential were connected to the negative pole of the defibrillator. The results in these series were: complete AV block in 33 cases (82 p. 100), partial AV block in 4 cases (11 p. 100) and failure in 3 cases (7 p. 100). Although the two series were not exactly similar, it seems permissible to recommend the second, more convenient technique.

Aged↗
PubMed1986

Comparison of the effects of muzolimine and a fixed combination of diuretics in essential hypertension.

The efficacy and tolerance of the loop diuretic muzolimine were compared with those of a fixed combination of hydrochlorothiazide and amiloride in patients with mild to moderate hypertension. After a placebo lead-in period, patients whose supine diastolic blood pressure was between 90 and 115 mm Hg were randomly allocated either to muzolimine, 20 mg/day, or to hydrochlorothiazide, 50 mg/day, and amiloride, 5 mg/day. The mean duration of follow-up was 4.7 months in both groups. Both muzolimine and the combination significantly decreased the mean blood pressure. The two treatments were similar in efficacy. The incidence of side effects during the trial was similar with both treatments, and no serious adverse reactions occurred. Eleven subjects in the muzolimine group were entered into an open long-term study. In all these subjects the blood pressure remained adequately controlled throughout the 4 to 6 months of additional follow-up and no side effects were reported. Muzolimine appears to be an effective and safe antihypertensive agent.

Administration, Oral↗
PubMed1986

Study of the electrophysiologic properties of clonidine administered intravenously.

A few cases of sinus node dysfunction (SND) and AV block (AVB) were described with clonidine therapy. The aim of this study is to evaluate the electrophysiologic properties of clonidine in volunteers with normal electrophysiologic data. Twenty-eight subjects were investigated by endocavitary techniques. The following parameters were measured before and 20 min after intravenous administration of clonidine: systolic and diastolic blood pressure (BP); sinus cycle (SC); PA, AH, and HV intervals; effective (ERP) and functional (FRP) refractory period of right atria (RA); AV node (AVN); His Purkinje system (HP); right ventricle (RV); corrected sinus node recovery time (SNRT); and sinoatrial conduction time (SACT). Blood pressure was reduced from 149/89 to 115/74 mm Hg. Sinus cycle was prolonged by 71 ms (p less than 0.01), corrected SNRT by 81 ms (p less than 0.05), and FRP of AVN by 16 ms (p less than 0.05). SND was more marked when initial SC was longer. Atrioventricular node depression was more marked when the PR interval was longer and when subject was older. Electrophysiologic effects of clonidine are similar to those of beta-blockers. The tensional effects are more marked than electrophysiologic effects. Clonidine in the high risk subject (age, bradycardia, long PR) may be cautiously dosed. Drug association with digitalis antiarrhythmic drugs, beta-blockers, and calcium antagonists may be avoided.

Adult↗
PubMed1986

Comparative study of the efficacy and tolerance of capozide and moduretic administered in a single daily dose for the treatment of chronic moderate arterial hypertension.

A comparative study was made of the effects of a new therapeutic agent consisting of 50 mg captopril and 25 mg hydrochlorothiazide (Capozide) with an already existing agent Moduretic (50 mg hydrochlorothiazide and 5 mg amiloride). In the Capozide group (32 patients), 20 achieved normal blood pressure, 8 responded but were not brought under control, and 3 were non-responders. In the Moduretic group (31 patients), 17 achieved normal blood pressure, 10 were partially controlled and 4 were non-responders. Moduretic appeared to be most effective in patients previously untreated or who had been taking only one drug, while Capozide controlled patients who had been taking 1 or 2 antihypertensive drugs which had been either ineffective or poorly tolerated. The long-acting effect of a single dose of Capozide was demonstrated by blood pressure measurements taken at least 10 hours later. Both drugs were generally well tolerated and no significant changes were observed in the laboratory measurements. The combination of an angiotensin converting enzyme inhibitor with a diuretic proved more effective than single agents in lowering raised blood pressure. We therefore conclude that Capozide is an effective alternative to traditional medication in the treatment of moderate hypertension.

Adolescent↗
PubMed1984

The prolonged antihypertensive effect of once daily atenolol: a study of continuous non-invasive arterial blood pressure monitoring.

This study was carried out on 12 hospitalized hypertensive patients to assess the antihypertensive efficiency and the duration of action of a once daily dose of atenolol. 100 mg of atenolol was given at 8 am every day for 5 days. Before and during the therapeutic period. 24-h blood pressure recordings were obtained with a continuous, automatic, non-invasive method working on the principle of oscillometry (Dinamap 845.950). Atenolol induced a significant reduction in mean blood pressure from 119 +/- 3.6 to 102.3 +/- 4.7 (P less than 0.001). This effect was significant from the very first day of treatment and was maintained over the duration of the study in ten patients. The decrease in blood pressure induced by atenolol lasted 24 h. Clinical tolerance of atenolol was excellent. In particular no case of excessive bradycardia was noted.

Adult↗
PubMed1983

Prevalence and significance of asymmetric septal hypertrophy in hypertension: an echocardiographic and clinical study.

To assess the prevalence of asymmetric septal hypertrophy (ASH) in hypertensive patients, 613 echocardiographic examinations performed over a period of one year were reviewed. Asymmetric septal hypertrophy (defined by an echocardiographic interventricular septum to left ventricular free wall thickness ratio of greater than or equal to 1.3 and by the presence of suggestive two-dimensional echocardiographic abnormalities) was found in 28 patients (5%). Clinical characteristics of asymmetric septal hypertrophy were assessed in 101 patients who underwent a complete evaluation. Patients with asymmetric septal hypertrophy (n = 9) were compared with patients with echocardiographic symmetrical left ventricle hypertrophy (n = 38) and without left ventricular hypertrophy (n = 54). Our results indicate that neither the severity of hypertension, nor the renin-angiotensin system nor sympathetic nerve activity appear to be the primary determinants in the development of asymmetric septal hypertrophy.

Adult↗
PubMed1982

Bidirectional tachycardia. Mechanism derived from intracardiac recordings and programmed electrical stimulation.

His bundle recordings and programmed electrical stimulation were performed in a 70-year-old woman with bidirectional tachycardia; the recordings demonstrated the infra-Hissian origin of the tachycardia. Occurrence of the His deflection slightly after the onset of ventricular depOlarization suggested that the origin of the tachycardia was located near the His bundle bifurcation. Recording of three atrial sites during tachycardia allowed the study of retrograde atrial activation. Two sets of fairly constant and alternating VA intervals were recorded. This fact is consistent with two ventricular circuits used alternatively. The tachycardia could also be interrupted with a single atrial or ventricular premature beat. It is postulated that the tachycardia is due to macroreentry involving the two fascicles of the left branch. This study suggests that reentry may be a possible mechanism in some cases of bidirectional tachycardia.

Aged↗
PubMed1982

[Mitral valve prolapse: do rhythm disorders have an electrophysiologic substratum?].

The mechanism of arrhythmias in mitral valve prolapse (MVP) is still unclear. The aim of this study was to determine if there were electrophysiological features common to patients with MVP. Eighteen patients with MVP documented on echo and angiocardiography underwent electrophysiological investigation. The series comprised 5 patients with ventricular arrhythmias and 5 with supraventricular arrhythmias, two of whom had ECG appearances of the Wolff-Parkinson-White, syndrome, and one a short PR interval. The RR interval, PR interval, intraatrial conduction (PA), atrio-hisian conduction (AH), intraventricular conduction (HV) the effective refractory periods of the atrium, AV node and ventricle, and the corrected sinus node recovery time were measured in the MVP group and in 20 presumed normal control subjects. There was a significant increase in the PR interval (p less than 0,05) at the expense of nodal conduction (AH) in the MVP group. In addition the Wenckebach point was significantly lower in this group. The other electrophysiological parameters in spontaneous rhythm and the atrial, AV nodal and ventricular refractory periods were the same in both groups. Sinus node function was comparable in both groups. In two patients without paiviously documented tachycardia, junctional tachycardia was initiated by provocative stimulation. However, no ventricular arrhythmias could be induced by pacing. A large number of preexcitation syndromes was observed in the MVP group (4/18), including one case of a latent Kent bundle, in patients with paroxysmal supraventricular tachycardias. On the other hand, the value of electrophysiological investigation seems to be limited for clarifying the mechanisms of the ventricular arrhythmias, probably because of their endomyocardial origin. Nevertheless, hemodynamic investigation showed abnormalities of left ventricular contraction in 4 of the 5 patients with ventricular arrhythmias.

Adolescent↗
PubMed1980

[Two dimensional echocardiography. Its main clinical applications (author's transl)].

The authors, who have experience of more than 1500 bidimensional echocardiographic recordings, underline the rapidity, safety and value of the method in cardiovascular disorders. The two-dimension echo provides better evaluation of the mitral area, right cavities and tricuspid valves. It is very sensitive in detecting mitral valve prolapse, pericardial effusion, intracavitary tumours and dissecting aneurysms and permits a detailed study of abnormal segmental contractions in ischaemic heart disease. Spatial and dynamic visualization coupled, if required, with contrast echocardiography is also of considerable help for the diagnosis of congenital cardiopathies.

Aortic Dissection↗