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Aims: The ECOST trial examined prospectively the long-term safety and effectiveness of home monitoring (HM) of implantable cardioverter defibrillators (ICD)., Methods and Results: The trial's primary objective was to randomly compare the proportions of patients experiencing ≥ 1 major adverse event (MAE), including deaths from all causes, and cardiovascular, procedure-related, and device-related MAE associated with HM (active group) vs. ambulatory follow-ups (control group) in a sample of 433 patients. The 221 patients assigned to the active group were seen once a year, unless HM reported an ICD dysfunction or a clinical event requiring an ambulatory visit, while the 212 patients in the control group underwent ambulatory visits every 6 months. The characteristics of the study groups were similar. Over a follow-up of 24.2 months, 38.5% of patients in the active and 41.5% in the control group experienced ≥ 1 MAE (P < 0.05 for non-inferiority). The overall number of shocks delivered was significantly lower in the active (n = 193) than in the control (n = 657) group (P < 0.05) and the proportion of patients who received inappropriate shocks was 52% lower in the active (n = 11) than in the control (n = 22) group (P < 0.05). At the end of the follow-up, the battery longevity was longer in the active group because of a lower number of capacitor charges (499 vs. 2081)., Conclusion: Our observations indicate that long-term HM of ICD is at least as safe as standard ambulatory follow-ups with respect to a broad spectrum of MAE. It also lowered significantly the number of appropriate and inappropriate shocks delivered, and spared the device battery. Clinical trials registration NCT00989417.

Aims: Intracardiac electrograms (IEGMs) recorded by implantable cardioverter-defibrillators (ICDs) are essential for arrhythmia diagnosis and ICD therapy assessment. Short IEGM snapshots showing 3-10 s before arrhythmia detection were added to the Biotronik Home Monitoring system in 2005 as the first-generation IEGM Online. The RIONI study tested the primary hypothesis that experts' ratings regarding the appropriateness of ICD therapy based on IEGM Online and on standard 30 s IEGM differ in <10% of arrhythmia events., Methods and Results: A total of 619 ICD patients were enrolled and followed for 1 year. According to a predefined procedure, 210 events recorded by the ICDs were selected for evaluation. Three expert board members rated the appropriateness of ICD therapy and classified the underlying arrhythmia using coded IEGM Online and standard IEGM to avoid bias. The average duration of IEGM Online was 4.4±1.5 s. According to standard IEGM, the underlying arrhythmia was ventricular in 135 episodes (64.3%), supraventricular in 53 episodes (25.2%), oversensing in 17 episodes (8.1%), and uncertain in 5 episodes (2.4%). The expert board's rating diverged between determinable IEGM Online tracings and standard IEGM in 4.6% of episodes regarding the appropriateness of ICD therapy (95% CI up to 8.0%) and in 6.6% of episodes regarding arrhythmia classification (95% CI up to 10.5%)., Conclusion: By enabling accurate evaluation of the appropriateness of ICD therapy and the underlying arrhythmia, the first-generation IEGM Online provided a clinically effective basis for timely interventions and for optimized patient management schemes, which was comparable with current IEGM recordings.

Background: Although implantable cardioverter-defibrillator (ICD) therapy has been evaluated in randomized controlled trials, enrolling highly selected patients, mortality events in ICD patients have received little attention in routine medical care. We sought to assess the 24-month total and cause-specific mortality rates and their predictors in "real life" patients with an ICD., Methods: The Evaluation Médico-Economique du Défibrillateur Automatique Implantable study was a French multicenter, prospective, observational cohort study of ICD patients with a 2-year follow-up. Cause-specific mortality rates and predictors at implantation of sudden cardiac death (SCD) or progressive heart failure (HF) death were assessed using competing risk methodology., Results: From June 2001 to June 2003, 2,296 unselected patients were implanted and followed until June 2005. During a mean follow-up of 20.5 +/- 6.7 months, 274 deaths occurred: 29 (10.6%) were SCD and 146 (53.3%) were HF deaths, corresponding to 24-month cause-specific mortality rates of 1.4% (95% confidence interval 0.9%-1.9%) and 6.9% (95% confidence interval 5.8%-8.0%), respectively. Among the characteristics at implantation, ejection fraction (EF) <30% and history of atrial fibrillation were independently associated with SCD; age, high New York Heart Association class, systemic hypertension, prior atrial fibrillation, QRS duration, EF <30%, and lack of beta-blocker therapy were independently associated with HF death., Conclusions: In this large cohort of "daily" patients, the 2-year incidence of SCD (1.4%) was comparable with the event rate observed in randomized controlled trials; HF remained the predominant mode of death. An EF <30% at implantation appears to be the most important predictor of ICD-unresponsive SCD.

Background: The long-QT and Brugada syndromes are important substrates of malignant ventricular arrhythmia. The feasibility of mapping and ablation of ventricular arrhythmias in these conditions has not been reported., Methods and Results: Seven patients (4 men; age, 38+/-7 years; 4 with long-QT and 3 with Brugada syndrome) with episodes of ventricular fibrillation or polymorphic ventricular tachycardia and frequent isolated or repetitive premature beats were studied. These premature beats were observed to trigger ventricular arrhythmias and were localized by mapping the earliest endocardial activity. In 4 patients, premature beats originated from the peripheral right (1 Brugada) or left (3 long-QT) Purkinje conducting system and were associated with variable Purkinje-to-muscle conduction times (30 to 110 ms). In the remaining 3 patients, premature beats originated from the right ventricular outflow tract, being 25 to 40 ms ahead of the QRS. The accuracy of mapping was confirmed by acute elimination of premature beats after 12+/-6 minutes of radiofrequency applications. During a follow-up of 17+/-17 months using ambulatory monitoring and defibrillator memory interrogation, no patients had recurrence of symptomatic ventricular arrhythmia but 1 had persistent premature beats., Conclusions: Triggers from the Purkinje arborization or the right ventricular outflow tract have a crucial role in initiating ventricular fibrillation associated with the long-QT and Brugada syndromes. These can be eliminated by focal radiofrequency ablation.

We report the observation of a female 45 year old patient presenting with a post-surgery complex congenital cardiopathy, associated with serious ventricular rhythm disorders necessitating the placement of an implantable defibrillator. The palliative surgery performed (cavo-pulmonary Glenn anastomosis) does not allow the usual access to the right ventricle via the superior vena cava. The different possibilities for defibrillator implantation are discussed. These include associating a surgical approach to introduce the bipolar probe with subcutaneous tunnelling to connect the probe to the box.

Aims: Preliminary studies have shown that peak endocardial acceleration (PEA), measured by a micro-accelerometer at the right ventricular apex, is highly correlated with left ventricular contractility (dp/dt max). Furthermore, changes in PEA are closely correlated with sinus node rate changes during exercise and during pharmacological interventions. Peak endocardial acceleration has, therefore, been used to drive a rate-responsive DDD pacemaker. This study compared the chronotropic performance of such devices implanted in 14 patients suffering from chronotropic incompetence with that observed in 18 control subjects in normal sinus rhythm., Methods and Results: Five standardized daily life activities (hall walk, climbing up and down stairs, squatting and hyperventilation) and two types of exercise (Bruce treadmill protocol and bicycle ergometry) were performed in a random order after individual programming of each pacemaker. For each test, a correlation coefficient was calculated between changes in PEA and variations in paced rate, between instantaneous variations in heart rate monitored by telemetry and continuous measurement of heart rate by the pacemaker, and between sensor-driven rate in patients and normal sinus rhythm in controls. The variations in paced heart rate were closely correlated with those observed in subjects with normal sinus rhythm, and proved to be sensitive, specific, rapid and independent of the type of exercise. After optimal programming of the sensor, PEA modulates the heart rate as expected during normal sinus rhythm., Conclusions: In this study, a single PEA sensor successfully restored chronotropic response in a population of paced patients with severe chronotropic incompetence. Peak endocardial acceleration can be monitored on a beat-to-beat basis, in parallel with heart rate, and the pacemaker can be accurately programmed with a single exercise test.

A retrospective study of 192 patients centered on the outcome of supraventricular arrhythmias after catheter ablation of the atrioventricular junction provided some useful information concerning the choice of pacing mode in these patients. With the exception of atrioventricular bloc after ablation of the rapid nodal pathway where simple DDD pacing is adequate, rate adaptive pacing would seem to be essential. The VVIR mode should be the mode of choice in atrial flutter, permanent atrial fibrillation, poorly controlled atrial fibrillation and paroxysmal atrial fibrillation of elderly subjects (over 70 years) and/or of male sex, and/or complicating advanced cardiac disease (valvular, ischaemic or primary). The DDDR mode (with an algorithm to prevent endless loop tachycardia) is the mode of choice in sinus node dysfunction and/or in young patients (under 60), and/or females and/or in idiopathic arrhythmias and/or when retrograde VA conduction persists. When the pacemaker is replaced, the indication should be reviewed with respect to the outcome of the arrhythmia, which underlines the value of accurate implanted Holter systems.

The introduction of ablative methods has revolutionised therapeutic strategy in cardiac arrhythmias. Accessory pathways are the most commonly targeted arrhythmogenic substrate. Several parameter may be used to determine the optimal site of ablation: accessory pathway potential, atrioventricular interval, atrial or ventricular pole of the pathway, morphology of the unipolar wave. The localisation of the accessory pathway sometimes requires specific techniques. The success rate reported in the literature is generally over 90%. However, the number of applications of radiofrequency current varies according to the authors from an average of three to eight. A combination of "timing related" criteria and direction of activation and the use of infraliminal stimuli minimise the number of radiofrequency applications. The incidence of complications in multicenter registers is 5% and the relapse rate is 8%. The long-term effects of catheter ablation are unknown, especially when used in childhood. A certain reserve should be maintained in the indications of ablation. Only high-risk, life-threatening arrhythmias, or those resistant to pharmacological intervention, are formal indications. Other (so-called "convenience") indications depend on the express wish of patients clearly informed of the advantages and risks of this method.

Catheter ablation techniques are now advocated as the first line of therapy for arrhythmias caused by accessory pathways (APs). The most common energy source is radiofrequency current, but technical characteristics vary. Several parameters can be used to determine the optimal target site: AP potential, AV time, atrial or ventricular insertion site, or unipolar morphology. Specific considerations are needed depending on AP location. Despite the different approaches described, there is no significant difference in the reported success rate, which is over 90%. However, the number of radiofrequency applications needed to achieve ablation appears to differ significantly, with median values from 3 to 8 reported. A combination of criteria related to both timing and direction of the activation wavefront or use of subthreshold stimulation could improve the accuracy of mapping. In patients with "resistant" APs, different changes in ablation technique must be considered during the procedure to achieve elimination of AP conduction. The incidence of complications in multicenter reports is close to 4%, with a recurrence rate of 8%. The long-term safety of catheter ablation requires further study.

Epidemiological data has established a relationship between left ventricular hypertrophy (LVH) and sudden cardiac death. This relationship is independent. The search for ventricular and atrial arrhythmias in hypertensives confirms a greater prevalence of these arrhythmias in patients with LVH. The mechanism of these arrhythmias is multifactorial: ischemia, subendocardial fibrosis, increased sympathetic tone, electrolyte disturbances, age, and hemodynamic changes may be arrhythmogenic substrates both at the ventricular and auricular levels. The relationship between LVH (marker or cause) and the detected arrhythmias remain obscure. The most sensitive markers of severity seem to be the ECG parameters (LVH with overload), echocardiographic mass (greater than + 20%) and septal thickness (greater than 12 mm). The evolution of arrhythmias with regression of LVH is unknown. Respect of electrolyte equilibrium would seem to be the only unquestioned therapeutic intervention.

Propafenone, an anti-arrhythmic medication recently introduced in class lc, was tested in a multicentric open study including 3,687 patients (mean age: 60 years), presenting a supra ventricular (n = 2,146, 59 p. cent), nodal (n = 351, 10 p. cent) or ventricular (n = 1,613, 44 p. cent) arrhythmia, in order to study its efficacy and tolerance. After exclusion of the patients on whom there was a contra-indications to the use of anti-arrhythmic drugs, Propafenone was administered orally, on a long-term basis, at the usual dose of 600-900 mg per 24 hours. The efficacy and tolerance were evaluated according to the usual clinical and paraclinical criteria (EKG, Holter) on the 15th day, then every month during the treatment period. The efficacy of the treatment was evaluated as very good in 54 p. cent of the cases, good in 25 p. cent of the cases, average in 8 p. cent of the patients and non-existent or non significant for 13 p. cent of the patients. Electrocardiographic alterations under Propafenone are already described: CF, PR, QRS. A cardiac undesirable side effect occurred 102 times, most often a sinus bradycardia type (n = 26), atrio-ventricular conduction disorders (n = 22) or intraventricular conduction disorders (n = 26), disorders of cardiac decompensation (n = 10) or arrhythmogenic effect (n = 18). Other side effects are gastro-intestinal in nature (taste alterations, nausea, vomiting, gastralgia) for 23 p. cent of the patients treated, neuro-sensorial in origin (dizziness, visual disorders, tremors) for 13 p. cent of the patients or of another nature for 5 p. cent of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

251 untreated patients with mild to moderate hypertension were included in a multicenter study aimed 1) to detect arrhythmias (24-H Holter recording) and 2) to assess the efficacy of sotalol on blood pressure and possible arrhythmias. Patients with coronary heart disease or previously documented arrhythmias were excluded. Atrial arrhythmias such as premature beats, fibrillation, flutter and paroxysmal atrial tachycardia were detected in 16% of patients. Monomorphic ventricular premature contractions (VPCs) (Lown I and II) were detected in 41% of patients and polymorphic VPCs or duplets/triplets (Lown III and IV) in 14%. A correlation seems to exist between the level of hypertensive cardiopathy, judged on electrocardiographic data (Tarazi classification), age of patients and severity of arrhythmias. Sotalol was administered during 2 months at a mean dose of 160 mg per day. The treatment was effective on blood pressure and arrhythmias (82% improvement of severe VPCs) and the drug was well tolerated. It was difficult to conclude if these good results are due to the betablocking properties or specific class II antiarrhythmic effects of sotalol or to the combined activity.

A population of 236 patients with dilated cardiomyopathy (DCM) was studied and followed up for an average of 38.8 +/- 27 months. The most common atrial arrhythmia was atrial fibrillation (AF) which was observed in 27 p. 100 of cases. Patients with AF (n = 43) and without it (n = 193) at the time of diagnosis were compared: the subjects with AF were older (p = 0.036), had a higher left ventricular ejection fraction and lower end diastolic pressures (p = 0.022). AF was associated with mitral valve prolapse (p = 0.007) and with signs of adiastole (p = 0.0015); the most significantly correlated variable was echocardiographic dilatation of the left atrium (p = 0.0012). AF was the presenting symptom of DCM in 13 cases (5.5 p. 100); in 10 cases (4 p. 100) it was the main clinical and therapeutic problem, realizing an arrhythmic form of DCM. Electrical conversion was successful in 7 out of 11 patients with a 2 year follow-up: 3 patients remained in sinus rhythm for over 6 years and have no clinical symptoms, posing the problem of the dominant if not exclusive underlying role of AF in these cases of DCM. An example illustrated by several echocardiographic examinations is presented. Embolic complications were observed in a quarter of the cases with AF and this arrhythmia was present in half the patients with embolic phenomena. However, the prognosis in the groups with and without AF was not significantly different.

Nine patients aged 47 to 74 years underwent endocavitary destruction of the bundle of His because of paroxysmal arrhythmias resistant to medical therapy. Four patients had paroxysmal atrial fibrillation, 2 had paroxysmal atrial flutter, 1 had reentrant atrial tachycardia, 1 had paroxysmal atrial tachycardia and 1 had an intranodal reentrant tachycardia. One patient had already undergone "surgical ablation" of the His bundle without success. A tripolar or bipolar catheter was introduced via the femoral vein and the His potential localised by bipolar and then unipolar recordings. The lead with the greatest His potential was connected to an external defibrillator and the other pole connected to a metal plaque positioned under the patient's left shoulder. An electrical shock of 200 to 400 joules was administered, in some cases repeatedly. Eight of the 9 patients developed complete atrioventricular block after the shock. This was only temporary in 3 cases, necessitating another shock in 2 cases; the procedure was not repeated in the 3rd case. After 30 minutes of persistent AV block a pacemaker was implanted; 7 of these 8 patients had VVI and I patient (intranodal reentry) DDD pacing. The follow-up period ranges from 1 to 18 months. None of the patients have had symptoms of paroxysmal arrhythmia; in the long-term, there was one initial failure. Of the other 8 cases, 4 remain in complete AV block, 2 have 2nd degree and 21st degree AV block. Three patients have associated antiarrhythmic therapy with quinidine or verapamil. No side effects were observed.(ABSTRACT TRUNCATED AT 250 WORDS)