Spatial distribution of electrical reconnection after pulmonary vein isolation in patients with recurrent paroxysmal atrial fibrillation.

INTRODUCTION: Recurrence of atrial fibrillation after pulmonary vein isolation (PVI) occurs frequently and may be associated with electrical reconnection of the pulmonary veins (PV). We investigated spatial distribution of electrical reconnection during re-do procedures in patients with paroxysmal atrial fibrillation who had previous successful acute electrical PVI with either single irrigated tip, antral ablation (s-RF; n = 38) or multi-electrode, duty-cycled ablation (PVAC; n = 48). METHODS AND RESULTS: EP navigator, mapping and irrigated tip ablation catheters were used in all re-do procedures. Sites of reconnection were assessed in a 12-segment model. Baseline clinical and demographic characteristics were similar in both groups. The number of PVs reconnected per patient was similar in both groups (2.9 ± 0.9 and 3.2 ± 0.7 (p = 0.193), s­RF and PVAC, respectively), and each PV was equally affected. However, the inferior quadrant of the right lower PV was significantly more vulnerable to reconnection after previous PVAC ablation, whereas the superior quadrant of the right upper PV showed significantly more reconnection in the s­RF group. CONCLUSION: The overall number of PVs reconnected was equally high in both groups, and each PV was affected equally. However, there were significant differences in the spatial distribution of electrical reconnection. Better understanding of predilection sites for reconnection might help to improve the long-term success rate of PVI.

[The implantable cardiac defibrillator: indications and complications]. / De implanteerbare defibrillator: indicaties en complicaties van de ICD.

The implantation of an implantable cardiac defibrillator (ICD) is indicated as a secondary prevention measure for sudden cardiac death in patients surviving a life-threatening ventricular arrhythmia that had no reversible or treatable cause. An ICD is indicated as a primary prevention measure for sudden cardiac death in patients with a left-ventricular ejection fraction (LVEF) ≤ 35%. A biventricular ICD is indicated in patients with heart failure class ≥ II according to the New York Heart Association classification, a widened QRS complex and an LVEF ≤ 35%. Guidelines do not differentiate between men and women or according to age, but there is no evidence in the literature for decreased mortality from applying ICD therapy in women and in patients older than 70-75 years. This is relevant in discussions over the cost-effectiveness of the treatment. Sudden cardiac death occurs most frequently in patients with an LVEF ≥ 35%; the effect of ICDs as a primary prevention measure in this patient group has, however, never been investigated. The most important complications following ICD implantation are inappropriate ICD shocks and lead dysfunction. Automated home-monitoring enables early detection of technical defects.

Remote care: bidding our ICD patients a fond farewell?

Remote follow-up has proven its safety and efficacy in the literature, and indeed in daily use. It saves the patient time and travel, allows earlier detection of events, and reduces inappropriate shocks. At the same time, it is not infallible and definitely not a universal substitute for in-office visits, as the 5 cases below demonstrate. It saves time, but also takes some time, with problems and challenges we were hitherto not familiar with. Hopes for the future include uniform definitions regarding policy and responsibilities, reimbursement, even better connectivity, better alert management and remote programmability. To end on a more utopic note, it would be a huge step forward if devices and leads were so reliable that we did not need remote care to detect malfunctions.

[Anticoagulation and atrial fibrillation]. / Antistolling en atrium fibrilleren: : Consequenties voor de kwetsbare oudere, en de valrisicomythe.

Atrial fibrillation (AF) is the most prevalent arrhythmia in man. Incidence increases with age, risk of ischemic stroke as a result of AF disproportionally so. Anticoagulation is therefore one of the cornerstones of treatment. Perceived severity of bleeding risk on anticoagulants is, however, one of the main reasons that the elderly population at highest risk is relatively undertreated.This article describes both risks for the traditional vitamin K antagonists,in addition to the new direct thrombin and factor Xa antagonists.

Aborted sudden cardiac death in a 52-yearold man without structural heart disease.

Sudden cardiac death in the absence of apparent structural heart disease is an uncommon phenomenon. The majority of these patients do not have 'normal' hearts and specific diagnostic tools are required to identify structural or functional abnormalities. We describe the history of a 50-yearold man who survived ventricular fibrillation. Clinical investigation, including a coronary angiography and electrophysiological study, appeared to be normal. An implantable cardioverter defibrillator was inserted. Follow-up Holter monitoring was performed after a recurrent episode of ventricular tachycardia. It demonstrated transient ST-segment elevation. An acetylcholine provocation test was subsequently carried out. Reversible coronary spasm of the left descending coronary artery was found, during which a diagonal branch was occluded. It may be concluded that coronary spasm provocation is of value in the routine diagnostic work-up of patients surviving sudden cardiac death without apparent heart disease. (Neth Heart J 2008;16:239-41.).

Implantable device recalls: are we throwing away the baby with the bath water?

Over the past year, there has been a sharp increase in the number of recalls, or `field safety corrective actions' concerning implantable defibrillators. This may be due to an actual rise in device or component-related problems (for which there is some evidence), overzealous reporting of potential problems (which is apparent), or most probably a combination of the two. In this day and age of increasing numbers of ICD implantations, it is essential that all concerned realise that ICDs are no more infallible than other man-made devices and that the incidence of complications is therefore likely to increase commensurately. It is also important to weigh the procedural risk of replacing the device against the risk not only of device failure, but more importantly related harm to the patient. Odds actually favour replacement in very few cases. Above all this demands critical attention to communication between stakeholders, medical, industry, patients and press. This article attempts to place a number of these issues in some perspective, and offer future directions for management of ICD recalls and safety actions.

Unmasking accessory pathway conduction due to AV block following tricuspid valve replacement.

Atrioventricular block during radiofrequency (RF) ablation of an accessory pathway may be due to inadvertent RF damage or catheter pressure to the conduction system, or a pre-existent conduction defect. Conversely, block in the normal conduction system may unmask pre-excitation. We describe a case where total infra-Hisian block complicated tricuspid valve surgery, unmasking a hitherto undiagnosed left lateral accessory pathway.

ICD-implantation guidelines versus clinical practice: a prospective study of out-of-hospital cardiac arrest survivors.

AIMS: The aim of this study was prospectively to compare clinical practice of implantable cardioverter defibrillator (ICD) use with current guidelines in out-of-hospital cardiac arrest (OHCA) survivors. METHODS AND RESULTS: From January 2000 till March 2002, 70 consecutive patients (pts) discharged from 15 hospitals after OHCA, with ventricular fibrillation (VF) as initial rhythm were included. Documentation of diagnosis, left ventricular function, ischaemia, electrophysiological studies (EPS), and decisions regarding ICD implantation were obtained from medical records. An expert committee compared these data with current guidelines. According to these guidelines 18 pts (26%) had an ICD indication and received an ICD while 37 pts (53%) had no indication and did not receive an ICD. In 13 pts without acute myocardial infarction insufficient diagnostic procedures were performed to permit a decision on ICD indication, hence no ICD was implanted. Two pts had an ICD indication but did not receive an ICD. During the follow-up with duration of 25 months (range 12-38 months), two sudden deaths occurred in the group of pts without an ICD. Of the pts with an ICD, 4 pts (22%) were reported to have received one or more shocks for VT/VF. CONCLUSION: In at least 21% of OHCA survivors, insufficient diagnostic procedures concerning the indication for ICD implantation were performed or no ICD was implanted when indicated, despite clear guidelines. In particular, there was no proof of ischaemia prior to revascularization and no confirmation of the absence of ischaemia and EPS thereafter. Clinicians should be guided better in evaluating pts after OHCA concerning the indication for ICD implantation, especially when a transient of reversible condition was present or when treatment was sufficiently established safely to refrain from ICD implantation.