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Biomedical subjects

G Fontaine

Publications and source records attributed to G Fontaine.

At least 163 records · Page 9Linked to original sources
PubMed1988

[Endocavitary fulguration in the treatment of cardiac arrhythmia].

Fulguration of the heart cavities seems currently to be a technique of increasing value in the treatment of untractable arrhythmias, of supraventricular junctional or ventricular origin. This study represents the evaluation of our experience with 64 patients, maximum follow-up is 54 months and the minimum follow-up is 7 months. Although the results are quite satisfactory in the fulguration of the bundle of his and in the fulguration of the arrhythmic site inducing ventricular tachycardia, these results are inferior in the Wolff-Parkinson-White syndrome in which fulguration of the coronary sinus seems contraindicated al filter (LEM type), resulting in the death of the patient. It is a true, early (1st week) migration after accurate positioning, opposite L4, and not an incident of insertion.

Adolescent↗
PubMed1988

[Surgical treatment of arrhythmia].

The surgical treatment of rhythm disorders began with interruption of the atrio-ventricular conduction by surgical section of the His bundle, then of the accessory path (Kent bundle) in the Wolff-Parkinson-White syndrome. Later on, surgery was extended to the treatment of chronic ventricular tachycardias. At a time when surgery seems to be progressively replaced by ablation methods using physical agents, electric shock or radio-frequency current, applied through endoluminal probes, it seemed justified to evaluate the established surgical procedures in the treatment of rhythm disorders. Therefore, this study proposes to review the current place of these methods which, in the last few years, have been modified in order to improve the quality of the results, decrease the mortality and specify their indications.

Arrhythmias, Cardiac↗
PubMed1988

[Sinocarotid hypersensitivity].

Hypersensitivity of the carotid sinus corresponds to a ventricular pause equal to or exceeding 3 seconds and/or a blood pressure drop equal to or exceeding 50 mmHg, induced by massage of the carotid sinus (MCS). MCS remains the diagnostic method of these two syndromes: cardio-inhibitor/vasodepressor. It must be performed systematically during the work-up of transient consciousness disorders since it is not unusual that hypersensitivity of the carotid sinus may cause cardiac syncopes. In addition, hypersensitivity of the carotid sinus is often associated with sinus dysfunction and atrioventricular conduction disorders. In the case of hypersensitivity of the carotid sinus with syncope secondary to a pure or dominant cardio-inhibiting response, heart stimulation with a dual-chamber pacemaker is probably the best treatment. In cases of hypersensitivity of the carotid sinus without syncope, therapeutic abstention is commonly accepted.

Arrhythmias, Cardiac↗
PubMed1987

The GAPO syndrome.

A new case of GAPO syndrome is described in a 4-year-old Algerian girl born of first-cousin parents. This patient also had a right pyelic kidney stone and cerebral venous circulation anomalies inducing scalp vein expansion.

Abnormalities, Multiple↗
PubMed1987

Treatment of resistant ventricular tachycardia by endocavitary fulguration associated with anti-arrhythmic therapy.

Endocavitary fulgurations were practised in 26 cases of high risk ventricular tachycardia (VT) for which antiarrhythmics including amiodarone and class I antiarrhythmic agents given alone or in combination proved ineffectiveness. Permanent VT was present in nine patients at the time of the fulguration session: three were moribund, and two were unconscious. Included in the series were 10 cases of arrhythmogenic right ventricular dysplasia, nine patients had chronic VT several months after myocardial infarction, four had a non obstructive cardiomyopathy, two were idiopathic and one came after repair of the right ventricular outflow tract. Fulguration succeeded in preventing VT in the 22 patients who survived the initial period of treatment in association with therapeutic antiarrhythmics, in eight cases. Three of the four early deaths were probably related to imperfections in the technique. Two late deaths were due to spontaneous evolution of the disease. The follow-up period ranges from a minimum of 15 to a maximum of 34 months, with an average follow-up of nearly two years. The success rate of fulguration alone or for patients receiving prophylactic antiarrhythmic drugs is 90%. Ten patients required two sessions or more before VT was brought under control.

Adolescent↗
PubMed1987

[Efficacy criteria in the fulguration of the bundle of His].

The authors have endeavoured to determine which of the parameters commonly used for His bundle ablation are likely to predict that ablation will be effective in altering the atrioventricular (AV) conduction system durability. His bundle ablation was performed in 18 patients (9 men, 9 women; mean age 47 years) presenting with supraventricular tachycardia refractory to all medical treatments. A total of 29 shocks were delivered with an Odam fulgurator, using a distal electrode connected to the positive pole of a selected catheter. Fifteen shocks were effective, resulting in a complete and permanent AV block (group I); the remaining 14 shocks failed to modify permanently the AV conduction system (group II). The parameters which differed between these two groups were the amplitude and the stability of the His bundle potential, the energy per kg bodyweight delivered with the shock and the possibility to shock the potential with the greatest amplitude in case of instability. A discriminant linear analysis showed that 3 interrelated criteria could be used to classify 83% of the shocks into one or the other group. In order of importance these criteria were: (1) amplitude of the His bundle potential; (2)energy delivered per kg bodyweight, and (3) stability of the potential. The corresponding discriminant values for successful results were more than 300 mV for parameter 1, more than 3 J/kg bodyweight for parameter 2 and very good stability of His bundle potential.

Adult↗
PubMed1987

[Cellular electrophysiological effects of fulguration by low energy shock].

In spite of the increasing use of catheter ablation in the treatment of refractory ventricular and supraventricular arrhythmias, little information is available on the basic electrophysiological effects of the treatment. Although high-energy shocks are still usually delivered, the current trend is toward lower energies. We studied the electrophysiological effects of non-deflagrating anodic shocks of 2 joules on preparations of sheep ventricular myocardium and Purkinje's fibers. The shocks were delivered by a standard defibrillator between a small-area catheter electrode and a wide-area inert electrode. Action potentials were recorded by the standard microelectrode technique. After the shocks were delivered, the Purkinje's cells that were 5 mm distant from the shocked area on either side were depolarized in the -30 to -40 mV zone, but they progressively reverted to an almost normal resting potential. Recovery was bi-exponential, with time constants of about 1 min and 10 min respectively. Similarly, the conduction block induced by the electric shock in 100% of the cases was reversible in 50%. It must be noted that at the time of conduction recovery the pattern observed was that of electrotonic conduction where the distal action potential conducted was preceded by a pre-potential. This pattern always regressed progressively, with gradual disappearance of the pre-potential in the distal cells, suggesting that the unexcitable area had vanished or become smaller. Although a normal 1/1 conduction and normal action potentials returned in the cells that were 5 mm distant from the shocked area, recordings performed at a distance of 1 to 4 mm from that area disclosed alterations of action potentials that were usually irreversible.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1987

Amiodarone drug interactions: potential beneficial and adverse effects.

The loading dose and maintenance of so called "resistant" cases by amiodarone oral intake is explained. In cases resistant to amiodarone alone, the combination of this drug is attempted with Class I antiarrhythmic agents. However, this association could interact with these drugs because amiodarone appears to have a definite action on the kinetics of several cardiovascular drugs. The association of amiodarone with a very low dosage of beta-blocking agents preventing interactions also looks promising. These remarks are provided in addition to classical limitations of the association of amiodarone because of pronounced interactions with other nonantiarrhythmic drugs such as warfarin or digitalis, which also should have dosage reduced to prevent side effects.

Amiodarone↗
PubMed1987

[Familial true hermaphroditism (apropos of 2 families)].

The authors report the cases of two new families of true hermaphroditism (4 cases) defined by the coexistence of both testicular and ovarian tissues. Exceptionally the disease presents a familial recurrence: only 8 families have been reported in the literature. When the study is done HY antigen is always increased in patients with true hermaphroditism and sometimes slightly increased in their mothers who are phenotypically normal.

Adolescent↗
PubMed1986

[Endocavitary fulguration in the treatment of ventricular tachycardia complicating myocardial infarction].

Endocardial catheter fulguration of ventricular tachycardia consists of sending a defibrillating shock to the tip of an endocavitary catheter lying near the site of origin of the tachycardia. The shock may modify the arrhythmogenic substrate and prevent relapses. We have used this method in 9 cases of post-infarction chronic ventricular tachycardia resistant to drug therapy, and the patients were be followed up for more than 2 years. The results were sometimes life-saving, even in cases with badly damaged myocardium. The electric shock did not significantly alter the myocardium but modified the arrythmogenic substrate enough to prevent long-term relapses. When insufficiently effective, endocardial catheter fulguration can be repeated without problems. Used alone or combined with antiarrhythmic drugs, it opens prospects of new radical therapeutic approaches.

Adult↗