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Fulguration is a new and promising technique for the treatment of cardiac arrhythmias. This paper discusses the methods and equipment used at Jean Rostand Hospital for invasive experimental research related to fulguration. The importance of catheter testing and selection is demonstrated. The most important features of the measurement techniques for both His bundle and ventricular tachycardia recordings are described. The main components of the protocols for fulguration and early post-operative surveillance are reported. The ODAM Fulgucor is used, augmented by the incorporation of additional pieces of equipment to allow monitoring of current and voltage curves. An electromechanic relay allows for automatic switching .from the recording amplifier to the energy source. The video system used includes recording of the image of the last fluoroscopic event with a character generator and an electronic pointer superimposed (when necessary). Computer programs for appropriate timing of predominant events have been developed. [ABSTRACT FROM AUTHOR]

Electrode catheter ablation (fulguration) is a new technique for the treatment of ventricular tachycardia resistant to medical treatment. It proved effective in our hands in a series of 65 cases of ventricular tachycardia of varied origin. This paper reports the early results in a subgroup of 13 patients suffering from arrhythmogenic right ventricular dysplasia in whom shocks ranging from 160 to 280 J, single or multiple, in one or up to three sessions were delivered. In the 11 patients surviving the DC ablation procedure single or multiple monomorphic sustained VT was brought under control. However, four patients (36%) required therapeutic antiarrhythmic treatment following the fulguration therapy. During the learning phase one case of death was related to poor catheter selection and the other to poor protocol. The post-mortem study of the effect of shocks depends on the anatomical structure to which the shocks have been delivered. [ABSTRACT FROM PUBLISHER]

We have reported here that a longer HV interval in association with a larger His amplitude yields a high rate of success when used to position the ablating catheter for His-bundle ablation. Additionally, we have shown that double discharge shocks are more effective than single discharge shocks, and that negative polarity is more effective than positive polarity. The use of bipolar or tripolar, and not quadripolar catheters, was also associated with a higher success rate. In our institution, using a bipolar catheter, we attempt to record an HV interval greater than 55 msec and a His amplitude greater than 0.35 mV. When both of these criteria are fulfilled, we use 3 to 4 joules per kg, and a single discharge shock. When one or the other of these criteria are not fulfilled, we use the double discharge shock method. Using these techniques, we have achieved successful His-bundle ablation with only one shock in all but one of the most recent 21 consecutive patients.

The authors studied the value and limitations of Holter monitoring and electrophysiological investigation in the evaluation of treatment of sustained monomorphic ventricular tachycardia (VT). One hundred and twenty-four consecutive patients were included in the study from January 1981 to February 1988. The etiologies were chronic myocardial infarction (N = 54), dilated cardiomyopathy (N = 24), right ventricular dysplasia (N = 31), and idiopathic VT (N = 15). All the tachycardias could be induced during baseline electrophysiological investigations and presented as complex ventricular arrhythmias on the Holter recordings. The investigations were repeated after treatment which was maintained irrespective of the results, unless the tachycardia which was induced or recorded was over 130 cycles/min and/or poorly tolerated. Recurrence was defined as the recording of VT in the absence of a change of treatment and/or the occurrence of sudden death. The follow-up period averaged 29 +/- 21 months. The Kaplan-Meier method was used to study the prevalence of absence of recurrence and survival rates. We observed 28 recurrences of VT and there were 21 deaths. Eighty-five per cent of patients had normal Holter monitoring after treatment. The prevalence of absence of recurrence was 0.751 when the Holter was normal and 0.485 when an arrhythmia was recorded (p = 0.03). The sensitivity was 25 per cent and the specificity 88 per cent. The survival rates were 0.66 and 0.585 respectively (p = 0.008). Fifty-three per cent of patients remained inducible after treatment with a prevalence of absence of recurrence of 0.572. This value rose to 0.877 when VT could not be induced (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Between 1983 and 1989, 69 patients underwent endocardial fulguration for drug-resistant VT which had several relapses per month, or were incessant. The etiologies were an old myocardial infarction, (25 cases) arrhythmogenic right ventricular dysplasia, (19 cases) dilated cardiomyocathy, (9 cases) left fascicular tachycardia, (9 cases) 5 right septal idiopathic tachycardia, and 2 congenital heart disease. The ejection fraction ranged between 12 and 30% in 25 cases. VT originated in 32 patients in the right ventricle, 31 in the left, and 6 had fulguration in both ventricles. 41 patients had 1 session, 22 needed 2, 4 had three sessions and 2 had 4. Five patients died during the procedure, four of low output, and three of them before the shocks. One died of tamponade. Two others had tamponade and were successfully drained. Four patients died during the first 3 months of preexisting heart failure without VT relapse. The remaining patients have a mean follow-up of 32 months, ranging from 3 to 72 months. 32 patients are off drug and had no relapse. 23 had early relapses, and are controlled by previously ineffective drugs. However 3 of these had a late sudden death (4, 14 and 22 months). 9 are treated with a combination of drug not tested before. The success rate ranges from 60% in septal VT to 74% in ARVD, 86% in MI and 100% in idiopathic left fascicular VT. The success rate increases with the number of sessiones. Fulguration alone, or combined with pharmacological agents can be considered as an effective therapy for VT, despite that it is neither simple, nor harmless.

The modification of AV conduction induced by 4 mg b.i.d. of lacidipine (L), a new calcium antagonist, was assessed by studying the changes in ventricular rhythm in 10 patients with stable chronic atrial fibrillation (mean age 71 +/- 15) by daily Holter recordings. The study was single blind versus placebo (P), nifedipine (N) 10 mg b.i.d. and for five patients diltiazem (D) 120 mg b.i.d. Five or seven consecutive 24 hours Holter were recorded in the following order: P, P, N or L, P, N or L, D, D. For each hour, an RR histogram was drawn and the 10 per cent and 90 per cent values of the cumulative cycle length curve were computed, as were the total number of QRS, and the mean value of RR intervals. The correlation coefficient between the number of QRS from the same hour on different days, the Student t test between the mean hourly RR interval values and the comparison between the histograms did not demonstrate a significant difference between the placebo, the nifedipine and the lacidipine periods. The only significant changes were induced by diltiazem (p less than 0.01), with a significant prolongation of the RR intervals. This suggests that lacidipine, like nifedipine, has no effect on AV conduction.

The authors studied the influence on recurrence and mortality of induced ventricular arrhythmias during electrophysiological studies performed to assess the efficacy of treatment of sustained monomorphic ventricular tachycardia. One hundred and twenty-six consecutive patients investigated from 1981 to 1988 were included. The underlying pathology was chronic myocardial infarction (N = 56), dilated cardiomyopathy (N = 24), right ventricular dysplasia (N = 31) and there were 15 idiopathic cases. All these tachycardias could be induced during the control study. A second test was performed after instituting treatment. This was maintained whatever the result of the electrophysiological study except in patients in whom the tachycardia rate was over 130/mn and/or poorly tolerated. Recurrences were defined as the observation of tachycardia with the same morphology and/or the occurrence of sudden death. Follow-up averaged 29 +/- 21 months. The absence of recurrence and survival were assessed by the Kaplan-Meier method and Logrank's test. It was not possible to induce any arrhythmia after treatment in 52 patients (41%). The prevalence of absence of recurrence in this group was 0.863. If the induction of ventricular fibrillation, doublets or short runs of VT (N less than 6 with no recurrences) are included, the value increased to 0.877. These patients were considered to be non-inducible. The prevalence of absence of recurrence of arrhythmia in patients in whom it was possible to induce sustained ventricular tachycardia of the same morphology as the clinical arrhythmia was 0.512 (p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

The fulguration procedure was originally introduced for the treatment of supraventricular arrhythmias by a pervenous interruption of His bundle conduction. This procedure has been extended to the treatment of almost any cardiac arrhythmia resistant to antiarrhythmic drug therapy. Recent results suggest that ablation could be selectively applied to the site of abnormal conduction. Overall results obtained at the Jean Rostand Hospital are reported for a series of 104 patients ranging in age from 14 to 83 years with atrial, junctional and ventricular tachycardias. The follow-up extends up to 65 months. Clinical efficacy, defined as a control of the arrhythmias by fulguration used alone or in association with drug therapy that was previously ineffective, lead to a success rate ranging from 80 to 85%. Mortality was less than 10% in the worst situation (chronic resistant ventricular tachycardia). Mortality was always related to inappropriate protocols. Therefore, fulguration, which was originally reserved to treat the most difficult cases, is now considered for non-life-threatening but incapacitating arrhythmias. Despite these results the technique is not simple. Fulguration should be performed by groups knowledgeable in electrophysiology and with expertise in high voltage electricity and biophysics.

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.

53 patients, between the ages of 14 and 76 years, presented a ventricular tachycardia which was treated by the fulguration method. 19 resulted from a complication of an old myocardial infarction, 15 from a right arrhythmogenic ventricular dysplasia, 8 from a dilated myocardiopathy. 10 patients presented idiopathic tachycardias: 3 originated in the infundibulum of the right ventricule and 7 from the left ventricle. One case originated from a surgical scar of the infundibulum. These tachycardias were continuous or occurred daily in half of the cases, or presented monthly recurrences. 1 to 17 shocks were delivered at each session, 143 on the right, 112 on the left and 2 transseptal. Four patients died from haemodynamic deterioration prior to the shock. The other 49 patients are considered as clinical successes. Three died within the first three months of low cardiac output without any recurrence of the tachycardia. 26 did not longer present any recurrent tachycardia and were not given any preventive anti-arrhythmic treatment. 19 developed recurrence or could be triggered off again, but the anti-arrhythmic medications which were ineffective, become effective. One female patient again developed slavos of ventricular tachycardia after a few months. Seven patients died 4 to 18 months after fulguration, and three presented a sudden death. They belong to the group with medically treated recurrences. This technique is a major factor in the therapeutic strategy of ventricular tachycardias, either used alone or associated with a pharmacological treatment.

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.

The kindling effect is an experimental model of epilepsy which results from an intermittent application of focal electrical stimulations to certain regions of the brain. Generalized seizures are usually obtained after about fifteen stimulations of amygdala in the rat. We studied the kindling effect in hyperbaric-hyperoxic conditions. Eleven Wistar rats were stimulated daily in a caisson and all stimulations were delivered after 30 min of diving at 3 ATA of air. Diving inhibited kindling in half animals. In the others, which all presented generalised convulsions, diving produced a reduction in seizure duration, especially during the generalisation phase.