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Fifteen years after the birth of resynchronization therapy, this technique has become one of the recommended treatments in severe heart failure patients, with low ejection fraction (4 35%), and conduction disorders (ORS > or = 120 ms). Based on large randomized clinical trials, the European recommendation is class I type (level of evidence A), to improve symptoms and survival of this patient population. Recommendations have been extended to patients already implanted with a conventional pacemaker, and to those with chronic atrial fibrillation. Recent results

Arrhythmias are more frequent in patients with sleep apnea syndrome. Bradycardias predominate. In the absence of controlled studies, it is difficult to link arrhythmias to sleep apnea syndrome or to the disease accompanying it (coronary disease, hypertension, etc.). Continuous positive airway pressure (CPAP) reduces arrhythmias significantly.

Biventricular resynchronisation is an additional therapeutic option in the management of refractory heart failure, with a functional and haemodynamic benefit as well as an improved morbidity and mortality. However, the rate of non-responsive patients has prompted a re-think about the presumed mechanisms of action for this procedure. This study aims to identify candidates more successfully. Based on five years experience in this centre, our work confirmed a medium and long term clinical benefit with multisite pacing. Nevertheless, there was evidence of a relative discordance between the functional benefit and the haemodynamic impact in terms of ejection fraction achieved with resynchronisation. While QRS narrowing appears to be a predictive factor for a successful procedure, the ECG alone is not sufficient to select 'unsynchronised' candidates. Statistical analysis reveals that before implantation the independent predictive factors to identify non-responsive patients include the presence of a complication of myocardial infarction and a low grade mitral leak. The limits of the ECG suggest a more mechanical than electrical approach to understanding the mechanisms of action for resynchronisation. Its effectiveness in cases of right bundle branch block confirm the hypothesis of left intra-ventricular conduction defects, not apparent on the surface ECG but accessible through new imaging techniques. Based on the hypothesis of delayed movement of the ventricular walls, the principle of resynchronisation aims to restore homogenous contraction. Echocardiography allows observation of electromechanical delay and opens new perspectives in the future for selecting patients for pacing. Ar

Biventricular resynchronisation has been recently shown to be an effective therapeutic option in patients with refractory dilated cardiomyopathy. Based on the finding of ventricular asynchrony, the aim of the method is to restore uniform contraction of the ventricular walls. However, the initial electrocardiographic criteria for selection of patients were only associated with a 70% rate of response. Consequently, it became necessary to refocus this method in patients with true ventricular asynchrony. Echocardiography is one of the non-invasive techniques which provides morphological and functional analysis of the myocardium with a high degree of accessibility. The multiplication of tools for echocardiographic quantification has been very valuable from a theoretical point of view for assessing ventricular asynchrony. In practice, techniques such as Doppler tissue imaging are being validated, but already offer the possibility of a multi-directional approach to this pathology. The diagnosis of asynchrony is based on a range of echocardiographic findings which not only improve the selection of patients but also optimise the programming of multisite stimulation.

Unlabelled: In patients with congenital heart block (CHB), dual-chamber pacing restores physiological heart rate and atrio-ventricular synchronization. However, patients with narrow QRS junctional escape rhythm may be deleteriously affected by long-term, permanent, apical ventricular pacing. We assessed the impact of apical ventricular pacing on echocardiographic ventricular dyssynchrony and hemodynamic parameters., Methods: Fourteen CHB adults (23 +/- years, 58% male), with a DDD transvenous pacemaker and a junctional escape rhythm (QRS<120 ms) before implantation, were studied. Echocardiography coupled with tissue Doppler imaging (TDI) and Strain rate was performed in spontaneous rhythm (VVI mode 30/mn) and during atrio-synchronized ventricular pacing., Results: The heart rate (43 +/- 09 vs 68 +/- 07: p<0.01), cardiac output (2.9 +/- 0.7 vs 3.7 +/- 0.6 L/min) and left ventricular filling time (325 +/- 38 vs 412 +/- 51 ms; p<0.01) were significantly less in the escape spontaneous rhythm compared with atrio-ventricular synchronized apical pacing. However, interventricular dyssynchrony (28 +/- 12 vs 59 +/- 25 ms, p<0.05), intra-left ventricular dyssynchrony (36 +/- 11 vs 57 +/- 29 ms; p<0.05), extent of left ventricular myocardium displaying delayed longitudinal contraction (26 +/- 10 vs 39 +/- 17%: p<0.05) were significantly less in the escape rhythm compared with paced rhythm., Conclusion: Once implanted with a DDD pacemaker, CHB patients present with increased cardiac output secondary to the restoration of physiological heart rate and improved diastolic function. However, the apical site is not optimal, as it creates detrimental ventricular dyssynchrony in patients with previous nearly physiological ventricular activation. Alternative pacing sites should be investigated.

Unlabelled: Catheter ablation techniques for atrial fibrillation have undergone an extensive evolution, starting with linear lesions in the right, then the left atria before being superseded by ablation of triggers, mainly from the pulmonary veins. We investigate the feasibility and results of combined pulmonary vein and linear ablation utilizing a specific linear lesion connecting the lateral mitral annulus to the left inferior pulmonary vein (left isthmus)., Methods: 115 patients (101 M: 54 +/- 9 years) with paroxysmal atrial fibrillation (7 +/- 5 years) resistant to 4 +/- 1.6 anti-arrhythmic drugs were studied. After electrophysiologically guided disconnection of all four pulmonary veins, the left isthmus line was performed with an irrigated tip catheter. Complete linear block was demonstrated during coronary sinus pacing by local mapping looking for widely separated double potentials and confirmed by differential pacing. Mapping and ablation from within the coronary sinus was performed if an epicardial gap was detected after unsuccessful endocardial radiofrequency delivery., Results: 100% of pulmonary veins were successfully disconnected and the left isthmus line was complete with bi-directional block in 88% after a mean of 22 +/- 12 min of endocardial radiofrequency delivery in 44 patients. In 58 patients, additional radiofrequency delivery was required from within the coronary sinus for 5 +/- 5 min. After a follow-up of 6.5 +/- 2.6 months and a mean of 1.4 +/- 0.6 procedures/patient, 79% were in stable sinus rhythm without antiarrhythmic drugs., Conclusion: the left isthmus line is feasible and safe and when performed in addition to pulmonary veins isolation can contribute to an increased success rate.

The evaluation of multisite stimulation with a haemodynamic aim has since its origin clashed with the absence of definition of a simple method of identifying candidates and of evaluation of the effects of treatment. In this pilot work, 66 patients were selected on electromechanical criteria obtained from a desynchronisation model identified from simple echographic parameters. The short term results demonstrate important modifications, differing according to the type of patient undergoing implantation. These results reject the basis of a prospective multicentric study aimed at validating the concept of ventricular resynchronisation.

Congenital ectopic junctional tachycardia (EJT) is a rare arrhythmia presenting in the first 6 months of life. It is often resistant to antiarrhythmic drugs and its poor prognosis (35% mortality) explains its often complex management. The authors report two cases which illustrate its unpredictability with a potential to degenerate to serious ventricular arrhythmias. The possibility of progression to atrioventricular block, increased by antiarrhythmic therapy, may lead to implantation of a cardiac pacemaker. The poor outcome of the two babies underlines the severity of these arrhythmias.

Quality of life (QOL) measurements are one of the main determinants for indication and technologic choice in permanent cardiac pacing. QOL measurements are obtained using questionnaire application. Questionnaire for QOL has to be reliable, comprehensive, sensitive and specific. Pacing mode and pacemakers algorithms have been evaluated by QOL measurements: VVI vs DDD, DDD vs VVIR, AAI vs DDD, fall back, algorithm.... Survival data and costs are also relevant aspects of cardiac pacing evaluation.