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J Tonet

Publications and source records attributed to J Tonet.

At least 19 recordsLinked to original sources
PubMed2005

[Arrhythmogenic right ventricular dysplasia and sudden cardiac death].

ARVD manifests itself by a wide spectrum of clinical presentations from asymptomatic patients to a broad range of ventricular arrhythmia, extrasystoles, tachycardia, or sudden arrhythmic death which can be the first symptom. It is a major cause for sudden death in young people and sportsmen. In known ARVD the risk of sudden death is not easy to assess from the literature, as its natural history is modulated by the wide variety of antiarrhythmic therapies. Hemodynamically ill tolerated ventricular arrhythmia, left ventricular involvement, sports, a youger age below 35, and uncontrolled therapy seem to predict an adverse outcome for these patients. These data may be helpful to decide for an AICD.

Age Factors↗
PubMed2002

[Atrial flutter with 1/1 nodo-ventricular conduction with amiodarone. From physiopathology to diagnosis].

Atrial flutter with 1/1 nodo-ventricular conduction is a classical complication of Vaughan-Williams's Class I antiarrhythmic drugs. The increase of the flutter cycle and weak action of the antiarrhythmic on the atrioventricular node leads to 1/1 conduction of atrial depolarisation to the ventricles. In view of their marked action on the atrioventricular node, this type of pro-arrhythmic effect is very unexpected with Class III antiarrhythmics. The authors report 7 cases of 1/1 atrial flutter with oral amiodarone observed between 1994 and 2001. The patients were 6 men and 1 woman with an average age of 58 +/- 14 years. Four of them had underlying cardiac disease; none were hyperthyroid. The initial arrhythmia was 2/1 atrial flutter (n = 4), 1/1 atrial flutter (n = 2) and atrial fibrillation (n = 1). Treatment was preventive with doses of 400 mg/day associated with carvedilol in one patient and 200 mg/day in another. The other five patients all received loading doses of 9200 +/- 2400 mg over 10 +/- 4 days. The symptoms were palpitations (n = 2) associated in one patient with hypotension, one syncope, one near syncope and one cardiogenic shock. The ventricular cycle of the 1/1 flutter was 287 +/- 33 ms. The QRS duration was 136 +/- 35 ms with ventricular tachycardia-like appearances in 3 cases. An adrenergic trigger factor was noted in 5 patients. One patient required emergency cardioversion. The authors discuss the physiopathology of 1/1 flutter and theoretical diagnostic methods are proposed. In conclusion, amiodarone does not always prevent the occurrence of 1/1 nodo-ventricular conduction in atrial flutter.

Administration, Oral↗
PubMed2000

Ventricular tachycardia catheter ablation in arrhythmogenic right ventricular dysplasia: a 16-year experience.

Arrhythmogenic right ventricular dysplasia (ARVD) is a structural heart disease affecting young adults that leads to cardiac rhythm disorders including supraventricular and mostly ventricular arrhythmias. Sudden death may be the first presentation of the disease. Ablation techniques have been used for the treatment of ventricular tachycardia in cases resistant to drug therapy. Radiofrequency is appropriate as a first approach for ventricular tachycardia ablation in ARVD; however, its effectiveness is less than 40% at the first session. Fulguration is effective for ventricular tachy-cardia ablation and should be used in the same session after ineffective radiofrequency ablation. However, fulguration requires expertise, general anesthesia, and more than one session in half of all patients. Radiofrequency and fulguration plus other common forms of treatment including pacemakers and automatic implantable cardioverter defibrillators provides a clinical success rate of 81% to 93% in a series of 50 consecutive patients studied during 16 years. Earlier poor reputation of fulguration was the result of poorly understood technical problems concerning the physics and biophysics of the procedure under control with presently available methods. This in-depth study of a large population over a long time period demonstrates that fulguration should be rehabilitated.

Adolescent↗
PubMed2000

[Burst of idiopathic ventricular tachycardia complicated by arrhythmia-induced cardiomyopathy].

The authors report the case of a young man with idiopathic ventricular tachycardia occurring in bursts and arising from the pulmonary infundibulum. During follow-up, progressive, severe, dilated cardiomyopathy was observed. Radiofrequency ablation of the site of origin of this very active arrhythmia resulted in total regression of the cardiomyopathy. Contrary to generally accepted concepts, paroxystic ventricular tachycardia, usually qualified as benign, may be complicated by cardiomyopathy when the ventricular extrasystole is incessant and repetitive.

Adult↗
PubMed1999

Radiofrequency catheter ablation of common atrial flutter: role of the eustachian valve.

INTRODUCTION: During radiofrequency catheter ablation of a common atrial flutter between the tricuspid annulus and the Eustachian valve "septal isthmus", double potentials were recorded along the Eustachian valve, previously described as an anatomical line of conduction block between the coronary sinus ostium and the inferior vena cava. RESULTS: Just before flutter termination, lengthening and beat to beat delay variations between the 2 components of the double potentials were correlated with simultaneous modifications of the flutter cycle length. CONCLUSION: The "septal isthmus" is a common pathway for the flutter wavefront and the impulse generating the second component of the double potential. It is also a good target for flutter ablation.

Adult↗
PubMed1999

Efficacy and safety of mizolastine 10 mg in a placebo-controlled comparison with loratadine in chronic idiopathic urticaria: results of the MILOR Study.

BACKGROUND: Mizolastine is a novel histamine H1-antagonist registered in Europe for the management of allergic rhinitis and urticaria. OBJECTIVES: To compare the clinical efficacy and safety of mizolastine with loratadine and placebo in patients with chronic idiopathic urticaria (CIU). METHODS: A multicentre, double-blind, parallel group study was designed in which 247 patients with CIU were randomised after a 1-week placebo run-in period to 10 mg daily mizolastine (n = 88), 10 mg daily loratadine (n = 79), or placebo (n = 80) for a 4-week treatment period. RESULTS: Mizolastine and loratadine both relieved symptoms of CIU. After 2 weeks' treatment, the severity of pruritus (visual analogue score (VAS) assessed by patients) decreased significantly in both the mizolastine and loratadine groups compared with placebo (mizolastine: -36.7 mm, P = 0.0001; loratadine: -29.8, P = 0.0071; placebo: -16.3); this improvement with both active treatments was maintained throughout the treatment period, the difference being significant only for the mizolastine group (P = 0.0090). Both active treatments were also associated with reduced weekly episodes of urticaria compared with placebo, which was significant after 2 weeks' treatment (mizolastine: 7.9 episodes, P = 0.0061; loratadine: 8.3, P = 0.0221; placebo: 13.3). Angioedema was improved to a clinically significant extent with mizolastine, and loratadine compared with placebo in those patients who had this symptom before treatment. Overall tolerability of both treatments was similar to placebo, and there were no clinically relevant effects on cardiac repolarisation with either mizolastine or loratadine. CONCLUSION: Mizolastine (10 mg daily) is confirmed as an effective and well tolerated agent, comparable to loratadine and superior to placebo, for the management of CIU. Mizolastine acted as rapidly as loratadine in improving urticarial symptoms from the first day of treatment.

Adult↗
PubMed1996

Diagnostic clues from the surface ECG to identify idiopathic (fascicular) ventricular tachycardia: correlation with electrophysiologic findings.

INTRODUCTION: An RS interval > 100 msec in precordial leads has been recently described for the diagnosis of ventricular tachycardia (VT). The aim of this study was to assess the value of this criterion when applied to patients with right bundle branch block pattern, left-axis deviation (fascicular) VT sensitive to verapamil. METHODS AND RESULTS: Eleven patients (mean age 31 +/- 11 years; range 16 to 51) had a mean heart rate of 164 +/- 37 beats/min (range 107 to 230) during VT. The QRS complex axis was -92 degrees +/- -15 degrees (range -80 to -115). The mean QRS duration was 121 +/- 9 msec (range 105 to 140). The mean RS interval was 67 +/- 9 msec (range 60 to 80). Fusion beats were present in 2 patients (18%), and AV dissociation confirmed by electrophysiologic study was found on ECG in 8 (73%) of 11. During tachycardia, the QRS-H' interval was 19 +/- 10 msec (range 10 to 30) in 6 of 11 patients. In seven patients, a fast, unique (or double) presystolic potential lasting 32 msec (range 12 to 40) occurring before the onset of the QRS complex was found at the site of origin of VT, localized in the inferior apical left ventricular septum. In all cases, VT was successfully treated by catheter ablation. CONCLUSION: A wide QRS complex tachycardia with right bundle branch block and left-axis deviation sensitive to verapamil observed in a young patient without structural heart disease should not be confused with supraventricular tachycardia with aberrancy but rather suggests the presence of fascicular VT. As opposed to VT associated with structural heart disease, the RS interval is < 80 msec in all precordial leads in all cases. Independent of this parameter, AV dissociation detectable on surface ECG has a sensitivity of 73%, which increases to 82% in the presence of fusion beats.

Adolescent↗
PubMed1996

[Role of power and temperature monitoring in radiofrequency ablation].

Variations of temperature, impedance and power and the relationship between these three factors were studied in 20 patients during 351 applications of radiofrequency energy delivered by a generator with a regulated output power. The applications were divided into 3 groups according to the maximal temperature attained: group I (< 50 degrees C; n = 112), group II (50-60 degrees C; n = 100), and group III (60-70 degrees C; n = 139). Analysis of the total duration of time of applications (average +/- standard deviation) showed: the duration (seconds) was 23.9 +/- 11.9 seconds for group I, 36.1 +/- 18.7 seconds for group II and 45 +/- 23.6 seconds for group III. The time to attain maximal temperature was 6.8 +/- 9.6 seconds in group I, 11.7 +/- 12.7 in group II and 10 +/- 10.4 seconds in group III. The impedance remained under 200 omega in all applications, the target temperature being set at 70 degrees C. Analysis of the first three seconds of application: correlations coefficients between temperature and impedance were -0.08 (p < 0.001) in group I and -0.23 (p < 0.0001) in groups II and III. These coefficients were recalculated with respect to the average power delivered during the applications: < 40 watts (n = 79), r = -0.33; < 30 watts (n = 55), r = -0.41; < 20 watts (n = 33), r = 0.49 and < 10 watts (n = 15), r = -0.7 (p < 0.0001). The authors conclude that radiofrequency generators with thermal regulation allow early interruption of ineffective applications of radiofrequency and avoid increases in impedance. The poor correlations observed between increase in temperature (measured at the tip of the catheter) and the fall in impedance (related to tissue heating) for the first 3 groups, show that temperature alone is not a good indicator of contact. The improvement of the correlations for decreasing output power applications indicates better thermal transfer between the electrode and endocardium. Therefore a low power delivered in the first seconds at > 50 degrees C is to be interpreted as a marker of the quality of contact and a predictive factor of efficacy.

Adolescent↗
PubMed1996

[Radiofrequency catheter ablation of ventricular tachycardia].

Radiofrequency energy was used for the ablation of chronic recurrent ventricular tachycardia (VT) in 58 patients who were divided into two groups: 44 cases with structural myocardial disease (36 men and 8 women: mean age 55 years; range: 14 to 85 years) with an average left ventricular ejection fraction of 38% (range: 15 to 80%): these patients had myocardial infarction (28 cases), arrhythmogenic right ventricular dysplasia (11 cases), idiopathic dilated cardiomyopathy (2 cases), operated congenital heart disease (2 cases) and operated valvular heart disease (1 case). The clinical success rate after the first session of radiofrequency ablation was 34%. When (according to our modified protocol of fulguration) 160 joule cathodal shocks were delivered to the same catheter previously used for RF ablation during the same session or secondarily (13 cases), the success rate increased to 76%. The average follow-up period of the 37 survivors was 16.7 months. The second group consists of 14 cases without structural myocardial disease (10 men and 4 women, mean age 41 years, range 14 to 69 years) with an average left ventricular ejection fraction of 61%. These patients had idiopathic ventricular tachycardia (10 cases) and verapamil-sensitive ventricular tachycardia (4 cases). The primary success of radiofrequency ablation alone was 43%. When combined with fulguration during the same of radiofrequency ablation alone was 43%. When combined fulguration during the same of at a later session, the success rate increased to 71.3%. The average follow-up period of the 13 survivors was 19 months (range 0.3 to 39 months). No significant difference was observed between the groups with or without structural myocardial disease after radiofrequency or fulguration ablation, not only with respect to global results but also after analysis of subgroups with, for example, post-infarction ventricular tachycardia or arrhythmogenic right ventricular dysplasia. However, clinical success was obtained after a single session of radiofrequency ablation alone in 8 of the 9 cases of incessant ventricular tachycardia in patients with structural myocardial disease.

Adolescent↗
PubMed1996

[Combination of celiprolol and amiodarone in the treatment of recurrent ventricular tachycardia].

The combination of beta-blockers and amiodarone has been shown to be affective in the treatment of refractory chronic ventricular tachycardia. However, the possible induction of excessive sinus bradycardia can constitute a limitation to the use of this treatment. Celiprolol is a cardioselective beta-blocker with a partial beta-2 agonist activity and an alpha-2 blocking activity, with a minimal depressant effect on heart rate. It therefore seemed useful to evaluate this drug in combination with amiodarone in patients with chronic ventricular tachycardia refractory to amiodarone alone. Twelve men with age of 57 +/- 16 years (9 with a history of myocardial infarction) received 200 mg of celiprolol per day associated with an average of 2 grams of amiodarone per week. Failure of oral amiodarone alone was confirmed by "reloading" (1,200 mg per day for 4 days) in 11 patients. The mean left ventricular ejection fraction was 36 +/- 19%, and was < or = 30% in 5 patients. Three patients were classified as stage 3-4 of the NYHA functional classification. Episodes of tachycardia were paroxysmal in 10 patients and diurnal in 10 cases. The effects of treatment were evaluated by clinical examination, continuous electrocardiographic monitoring, stress test and endocavitary electrophysiological investigation. No patient developed cardiac decompensation or collapse during beta-blocker treatment. In one case, the dose of celiprolol had to be decreased to 100 mg per day because of hypotension. No proarrhythmic effect was observed. The sinus rate remained unchanged after addition of celiprolol to amiodarone (57 +/- 3 bpm before versus 56 +/- 4 bpm after). On the stress test, the exercise capacity was maintained and no tachyarrhythmia was induced. Right ventricular refractory periods were not modified by celiprolol (mean effective period 289 +/- 20 ms before versus 294 +/- 20 ms after). Following a hospital stay of 17 +/- 7 days, the beta-blocker was discontinued in 5 patients because of persistence of permanent tachycardia in 1 case, and because of inducibility of a tachycardia with the same frequency as before treatment in the other 4 cases. No sudden death or haemodynamically unstable recurrence of ventricular tachycardia were observed during follow-up over a period of 38 +/- 24 months (range: 2-55) of the 7 patients in whom treatment was considered to be effective. Only one patient presented a temporary and reversible deterioration of heart failure. The absence of excessive bradycardia was also observed during follow-up. In one patient, celiprolol was replaced by another antiarrhythmic due to the recrudescence of inducibility to programmed stimulation. Three patients developed a spontaneous recurrence of sustained monomorphie ventricular tachycardia, which was well tolerated. In conclusion, these results suggest that celiprolol in combination with amiodarone in the treatment of refractory chronic ventricular tachycardia is a valuable therapeutic option because of its good inotropic and particularly chronotropic safety. However, the efficacy of treatment must be evaluated by a stress test and by endocavitary electrophysiological investigation including programmed ventricular stimulation in every case.

Adrenergic beta-Antagonists↗
PubMed1995

Time- and frequency-domain analyses of the signal-averaged ECG in patients with arrhythmogenic right ventricular dysplasia.

BACKGROUND: Arrhythmogenic right ventricular dysplasia (ARVD) is characterized by recurrent ventricular tachycardia of right ventricular origin and a cardiomyopathy with hypokinetic areas involving the free wall of the right ventricle. Subjects have a risk of sudden cardiac death, particularly during sports and strenuous exercise. Routine clinical examinations may be normal, but fragmented or delayed electrograms are usually recorded in the right ventricle of these patients. However, the frequency with which late potentials are detected by conventional time-domain analysis of the signal-averaged ECG (SAECG) is not high. This study evaluated the usefulness of the frequency-domain analysis of the SAECG in addition to the conventional time-domain analysis for a screening test to detect patients with ARVD. METHODS AND RESULTS: SAECG was recorded by using a bipolar X, Y, and Z lead system in 28 patients with ARVD (mean age, 38 +/- 13 years) and 35 age-matched normal subjects (mean age, 35 +/- 11 years). The conventional time-domain analysis of the SAECG was performed at two different high-pass filter settings, 25 and 40 Hz, and the low-pass cutoff frequency was fixed at 250 Hz. The fast-Fourier transform analysis of SAECG was performed using a Blackman-Harris window. Area ratio 1 (area of 20 to 50 Hz)/(area of 0 to 20 Hz) and area ratio 2 (area of 40 to 100 Hz)/(area of 0 to 40 Hz) were calculated. In the conventional time-domain analysis, 20 (71%) and 18 (64%) patients had positive criteria at filter settings of 25 and 40 Hz, respectively. In the frequency-domain analysis, 18 (64%) and 20 (71%) patients had abnormal values in area ratios 1 and 2, respectively. Combining the time- and frequency-domain analyses, all patients were judged positive, with a sensitivity of 100% and a specificity of 94%. CONCLUSIONS: Each result of the time- and frequency-domain analyses revealed that both methods had equivalent value. Combining the two domain analyses improved the sensitivity without reducing the specificity. These findings suggest that combining the time- and frequency-domain analyses of the SAECG may be useful as a screening test to detect patients with ARVD.

Adult↗
PubMed1995

The arrhythmogenic right ventricle. Dysplasia versus cardiomyopathy.

Twenty-four patients presenting with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ventricular tachycardia of right ventricular origin associated with structural abnormalities of the right ventricle) were divided into two groups with left ventricular ejection fraction (LVEF) above or below 45%. The distribution of LVEF in the group with LVEF below 45% was comparable with the distribution in 6 patients with idiopathic dilated cardiomyopathy who had ventricular tachycardia originating in the left ventricle (P = 0.2). They also had the same unfavorable long-term prognosis. Therefore, it is suggested that the term, arrhythmogenic right ventricular cardiomyopathy (ARVC), be restricted to patients with a LVEF below 45%. Histological data obtained in the ARVC group showed signs of acute or chronic myocarditis (in the right and left ventricles). It can be hypothesized that patients with arrhythmogenic right ventricular dysplasia (ARVD) may be prone to develop infectious myocarditis. In patients in whom an abnormal host immune response had been seen, progressive deterioration of right and left ventricular function could be observed. This pattern may be superimposed on the genetically determined background of ARVD. This could explain the wide spectrum of clinical presentation observed in patients with tachycardia originating in an abnormal right ventricle.

Adolescent↗
PubMed1995

[Outcome of arrhythmogenic right ventricular dysplasia. Apropos of 4 cases].

The authors propose a classification of the outcome of arrhythmogenic right ventricular dysplasia with reference to 4 selected cases with a follow-up period of over 9 years. In type I, the left ventricular ejection fraction is normal (EF > 50%) and the risk, exclusively arrhythmic, can be controlled by appropriate antiarrhythmic therapy. This is the commonest form of arrhythmogenic right ventricular dysplasia with different varieties according to the degree of dilatation of the right ventricle. In type II, there is a variable degree of left ventricular involvement (30 < EF < 50%) either by extension of a comparable disease process as observed in the right ventricle or by an isolated or superimposed phenomenon of myocarditis. This form is stable and may remain stable for many years providing the arrhythmias are correctly treated. In type III, progressive degradation of the myocardium is observed over a period of about 10 years with a clinical presentation comparable to that of certain arrhythmogenic dilated cardiomyopathies which are often hereditary. In this case, the patients have an arrhythmic risk associated with that of cardiac failure which becomes progressively irreversible. The histology shows interstitial fibrosis with biventricular lymphocytic infiltration suggesting an autoimmune phenomenon. Therefore, the classification of cases of arrhythmogenic right ventricular dysplasia depends on the potential evolutivity of the lesions. When the patient is seen in the early stages of the disease, the prognosis should be garded, especially in a hereditary form.

Adult↗
PubMed1995

Idiopathic ventricular tachycardia: feasibility and efficacy of catheter ablation.

Idiopathic ventricular tachycardia is a well described syndrome of both left and right ventricular origin. This study reports the feasibility and efficacy of catheter ablation in this entity. Fourteen patients (mean age 30 +/- 10 years of age) and six patients (mean age 51 +/- 9 years of age) underwent endocardial catheter ablation with either direct-current shocks and radiofrequency energy, respectively. Earliest right and left ventricular activation and endocardial mapping during tachycardia were made to localize the site of ventricular tachycardia origin. The overall clinical efficacy was 93% for direct-current method with a mean number of shocks of 3.3 +/- 0.9/patient after a mean follow-up of 38 +/- 25 months. Radiofrequency ablation achieved an overall clinical efficacy of 83.6% with a mean of 3.2 pulses/patient during a follow-up of 10.5 +/- 4 months. The isoenzyme MB fraction of peak creatine kinase after ablation was less than 5%. There were no complications in any patient who underwent radiofrequency energy. Endocardial catheter ablation is feasible in patients with idiopathic ventricular tachycardia. Both methods are highly effective but radiofrequency energy is most desirable because of its lack of barotrauma, and may be considered as early therapy.

Adult↗
PubMed1995

[Arrhythmogenic right ventricle: dysplasia or cardiomyopathy? Value of left ventricle ejection fraction].

The left ventricular ejection fraction (LVEF) of 76 patients suffering from arrhythmogenic dysplasia or cardiomyopathy of the right ventricle (ventricular tachycardia associated with structural abnormalities of the right ventricle) demonstrated two subgroups situated above and below 45%. Values of LVEF less than 45% were similar to those of a control population of 6 cases of idiopathic dilated cardiomyopathy with ventricular tachycardia of left ventricular origin (p = 0.2). These patients also have the same unfavourable long-term prognosis. Histological data obtained from four cases belonging to the group of patients with dysplasia or cardiomyopathy of the right ventricle with a low ejection fraction demonstrated the presence of signs of myocarditis involving both ventricles. This suggests that these patients may suffer from an infectious phenomenon superimposed on a specific histological substrate, which may lead to deterioration of their myocardial function. These results are in line with those of the literature. The term arrhythmogenic cardiomyopathy of the right ventricle should therefore be reserved to the subgroup of patients with an LVEF less than 45%. Finally, arrhythmogenic cardiomyopathy of the right ventricle appears to be a complication of dysplasia following the development of a myocarditic phenomenon. This may explain the wide range of clinical forms observed in patients with ventricular tachycardia of right ventricular origin associated with structural abnormalities of the right ventricle.

Adolescent↗
PubMed1995

[Supraventricular tachycardia with wide QRS complexes during Vaughan-Williams class I anti-arrhythmic treatment. Diagnostic and therapeutic implications].

The authors report 8 cases of regular tachycardia with wide QRS complexes during treatment with Vaughan-Williams class 1 antiarrhythmic drugs. These antiarrhythmics, prescribed to prevent atrial fibrillation (3 patients) and atrial flutter (5 patients), were flecainide in 4 cases, propafenone in 2 cases and cibenzoline and hydroquinidine respectively associated with digitoxine and propranolol. These wide complex tachycardias were regular atrial tachycardias with 1/1 conduction to the ventricle. The action of the drug, more pronounced on intra-atrial conduction velocities than on atrioventricular node refractoriness resulted in transformation of flutter at 300 cycles/min with 2/1 conduction and a ventricular rate of 150 cycles/min to atrial flutter at 210 cycles/min with 1/1 ventricular conduction. This acceleration of the ventricular rate was accompanied by widening of the QRS complex. Using the new ventricular tachycardia criteria recently published by Brugada resulted in a diagnostic error in 7 out of the 8 cases. The recording of a wide QRS complex tachycardia in a patient on class 1 antiarrhythmic therapy for an atrial arrhythmia should alert the physician to 1/1 atrial tachycardia despite morphological electrocardiographic criteria of ventricular tachycardia. The 1/1 atrial tachycardia may be poorly tolerated and require emergency treatment. The preventive association of a drug which slows conduction through the atrioventricular node is not always effective.

Adult↗