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J Tonet

Publications and source records attributed to J Tonet.

51 records · Page 3Linked to original sources
PubMed1990

[Congenital and acquired right ventricular dysplasia].

Arrhythmogenic right ventricular dysplasia has been described as a developmental malformation occurring during foetal life. This explains a number of familial cases of this condition where dysplasia was the result of a genetic abnormality transmitted in an autosomal dominant mode with incomplete penetrance. Histological data of peroperative or post-mortem specimens of 27 cases showed a large number of grape-like lymphoplasmocytic infiltrations. These appearances suggest an inflammatory origin of the disease, most probably related to an infective etiology. The authors suggest that in addition to the congenital form there may also be a possibility of acquiring arrhythmogenic right ventricular dysplasia after an episode of myocarditis.

Adult↗
PubMed1990

[Value and limitations of Holter monitoring and electrophysiologic testing in the evaluation of the treatment of sustained monomorphic ventricular tachycardia].

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)

Actuarial Analysis↗
PubMed1989

Treatment of rhythm disorders by endocardial fulguration.

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.

Arrhythmias, Cardiac↗
PubMed1989

[Efficacy of the combination of low doses of beta-blockers and amiodarone in the treatment of refractory ventricular tachycardia].

Thirty one patients aged 56 +/- 16 years with chronic ventricular tachycardias (VT) refractory to 4.4 +/- 1.8 antiarrhythmic drugs, used alone or in combination, were managed by low doses of beta-blocker agents combined with oral amiodarone, either after loading (1.2 g for 7 days, n : 7) or reloading (1.2 g for 4 days, n : 24) of amiodarone. All patients proved refractory to amiodarone alone. Nine VT were also refractory to endocardial catheter fulguration in 8 patients. Twenty one patients had coronary artery disease, 4 had arrhythmogenic right ventricular dysplasia, 4 had dilated cardiomyopathy, 1 had valvular disease, and 1 had no structural heart disease. Twelve patients had an ejection fraction less than 30 p. 100. Ten patients were in NYHA functional class 3. VT was permanent in 3 patients, daily in 5, weekly in 7, paroxysmal in 16. In 14 patients, VT occurred both at day and night. Oral administration of a daily low dose of a beta-blocker agent (acebutolol 100 mg, betaxolol 5-10 mg, metoprolol 50-100 mg, nadolol 20-40 mg, pindolol 2.5 mg, propranolol 30 mg, sotalol 80-160 mg, tertatolol 2.5 mg) combined with 400 mg per day of amiodarone suppressed VT episodes in all patients. None presented heart failure or collapse. The mean reduction of the heart rate was about 17 p. 100. One patient need a definite pacemaker to correct sinus bradycardia. At discharge, exercise ECG (n: 20) induced non sustained VT in 2 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Efficacy and safety of low doses of beta-blocker agents combined with amiodarone in refractory ventricular tachycardia.

Twenty patients aged 55 +/- 16 years with 40 chronic ventricular tachycardias (VT) refractory to 4.6 +/- 1.9 antiarrhythmic drugs, used alone or in combination, were managed by low doses of beta-blocker agents combined with oral amiodarone (Am), either after loading (1.2 g for 7 days, n: 5) or reloading (1.2 g for 4 days, n: 15) of Am. All patients proved refractory to Am alone. Seven VT were also refractory to endocardial catheter fulguration in six patients. Thirteen patients had coronary artery disease, three had arrhythmogenic right ventricular dysplasia, two had dilated cardiomyopathy, one had valvular disease, and one had no structural heart disease. Ten patients had an EF less than 30%. Ten patients were in NYHA functional class three. VT was permanent in three patients, daily in three, weekly in seven, paroxysmal in seven. In 11 patients, VT occurred both at day and night. In 11 patients, decrease of the sinus cycle preceeded VT. Oral administration of a daily low dose of a beta blocker agent (acebutolol 100 mg, betaxolol 5-10 mg, metoprolol 50 mg, nadolol 20-40 mg, pindolol 2.5 mg, propanolol 30 mg, sotalol 80-160 mg, terta-tolol 2.5 mg) combined with 400 mg/day of Am suppressed VT episodes in all patients. None presented heart failure or collapse. The mean reduction of the heart rate was 15% (65 to 55/min). At discharge, exercise ECG (n: 14) induced non sustained VT in two patients. At programmed electrical stimulation (PES) (n: 15), VT was no longer inducible in 4 patients, was slower, well-tolerated in nine patients, and remained inducible at the same rate in only two patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1988

[Rhythm and conduction disorders immediately after ventricular fulguration].

UNLABELLED: Forty-four patients with ventricular tachycardias (VT) refractory to medical treatment underwent 73 sessions of endocavitary electrode catheter ablation. The clinical series included 16 cases of post-infarction VT, 14 cases of arrhythmogenic right ventricular dysplasia, 6 cases of dilated cardiomyopathy, 6 cases of idiopathic VT, 1 case of sequela of myocarditis and 1 case of VT consecutive to surgical repair of a congenital cardiopathy. Cardiomegaly was present in 30 patients, and 16 patients had an ejection fraction of less than 30 p. 100. None of the patients were receiving digitalis or class I antiarrhythmic drugs when ablation was performed. A total of 235 shocks of 100 to 320 J (mean 221 +/- 42 J) were delivered. 115 shocks (49 p. 100) were complicated by dysrhythmia and/or disorders of conduction; 29 shocks (12 p. 100) induced 13 ventricular fibrillations and 16 ventricular tachycardias. No relation was found between energy delivered, shock synchronization, haemodynamic status, heart cavity treated, underlying heart disease, CK MB levels and these arrhythmias. On the other hand, ablations performed while the patients were experiencing VT increased the risk of arrhythmia (p less than 0.02). 36 AV blocks, 21 left bundle branch blocks, 12 right bundle branch blocks and 11 sinus bradycardia were observed. With the exception of one right bundle branch block and one left posterior hemi-block, all blocks were transient. IN PRACTICE: (1) electrode catheter ablation may be complicated by disorders of cardiac rhythm or conduction in 50 p. 100 of the cases; (2) these disorders can easily be corrected by stimulation or defibrillation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Endocardial fulguration for the treatment of ventricular tachycardia. Experience with 69 cases].

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.

Adolescent↗
PubMedDate not supplied

[Fulguration of extrasystolic ventricular focus].

A case is presented of symptomatic premature ventricular contractions refractory to drug therapy with right bundle branch block QRS morphology and left axis deviation in a 68-year-old female without structural heart disease. Endocardial mapping localized the extrasystolic focus at meso-inferoapical region of the left ventricular septum suggesting an origin from the Purkinje network of the left posterior fascicle. Catheter ablation with direct-current energy abolished extrasystolic complexes, without complications. The patient remained asymptomatic over a follow-up of 3 months.

Aged↗
PubMedDate not supplied

[Radiofrequency ablation in ventricular tachycardia: initial experience and evaluation of its limitations].

The purpose of this paper is to report our initial experience with radiofrequency catheter ablation in 21 patients with ventricular tachycardia of different etiologies and to evaluate the causes which play a role in its limitation. The results show a low rate of effectiveness: total clinical success of 43%. Nevertheless there was a high success rate in a specific subsets of patients. The results depends on several factors: the electrophysiologic mechanisms and substrates of the tachycardia, the criteria to localize the critical area perpetuating the arrhythmia and the biophysical aspects of radiofrequency energy. Its usefulness is manifested in ventricular tachycardia with structurally normal heart and it has a limited success in cases with organic heart disease. Improvement of technical aspects and better understanding of the mechanisms of the tachycardia and characteristics of the target site will enhance the results of radiofrequency catheter ablation in ventricular tachycardia.

Adult↗
PubMedDate not supplied

[Transcatheter ablation of atrioventricular accessory pathways. Immediate results and long-term follow-up].

We present the immediate results and follow-up, from our initial serie of patients, where radiofrequency was attempted to ablate atrio-ventricular accessory pathways. Initiation policy included direct current-shocks following every unsuccessful radiofrequency session. Initial ablation success rate with radiofrequency solely was 75% (17/22), same as when direct current-shocks were associated 80% (8/10); but accessory pathway conduction recurrence was present only in this latter (6/10). During follow-up period of 18 to 25 months, from the recurrence group, one patient had spontaneous delta-wave disappearance, and four more required two to three ablation sessions. Permanent elimination with both methods was attained in 91% (20/22 pathways), and all patients remain asymptomatic, and drug free. There were one acute major complication, but no deaths. Because of its superior initial success rate, minor technical requirements, and their economical implications, radiofrequency catheter ablation of accessory pathways is the first choice of treatment. At our institution, direct current-shock remain an alternative method whenever a serious tachycardia prevents radiofrequency treatment.

Adolescent↗
PubMedDate not supplied

[The radiofrequency and the elimination of accessory atrioventricular pathways. The factors related to successful transcatheter ablation].

Some factors related with successful radiofrequency catheter ablation were retrospectively analyzed from the initial patients with WPW syndrome that underwent this therapy. They were 21 patients, and success rate with radiofrequency therapy was 73%. Conventional conduction intervals were obtained from catheter ablation electrograms. Only ventricular activation around Delta-wave onset, and earliest retrograde atrial activation were statistically significant for successful ablation (P < 0.05 both). Inadvertent interruption of AV-His bundle was produced ablating a septal accessory pathway, and no mortality procedure-related was observed. We conclude that radiofrequency catheter ablation of accessory pathways represents nowadays, an effective solution in patients with symptomatic arrhythmias, besides its high success rate and low risks, but different mapping criteria should be considered to attain an efficient elimination of atrioventricular accessory-pathways.

Adolescent↗