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Background: After pulmonary vein isolation (PVI), patients need to be followed to analyze the effect of the treatment. We evaluated the influence of the duration of Holter monitoring on the detection of arrhythmia recurrences after a single PVI at 12 months., Methods: Consecutive patients with paroxysmal atrial fibrillation (AF) underwent successful PVI with phased radiofrequency and pulmonary vein ablation catheter. Follow-up was performed with electrocardiogram at 3, 6, and 12 months and 7-day Holter at 12 months. Symptomatic patients received additional event recording. The 7-day Holters at 12 months were evaluated for documented left atrial tachyarrhythmia recurrences, and each individual day with AF was categorized., Results: At 12 months after the procedure, 21 of the 96 (22%) patients had AF on their 7-day Holter. In the patients with AF recurrence, there was an increase in sensitivity from 53% of a 1-day Holter up to 88% with 4-day Holter, and 100% of a 7-day Holter. Monitoring with duration of less than 4 days resulted in significantly less detection of patients with AF compared to 7-day Holter., Conclusions: A 4-day Holter at 12 months has an 88% sensitivity for arrhythmia detection, and appears to provide a sufficient monitoring time. Prolonging the monitoring time to 7 days does not significantly increase the yield., (©2011, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.)

Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting millions of individuals worldwide, and a major risk factor for disabling cerebral embolic stroke. Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant inherited disorder, characterized by vascular abnormalities with high-bleeding tendency and therefore intolerance for oral anticoagulation. We report a case of percutaneous closure of the left atrial appendage, which might be a good alternative strategy instead of chronic oral anticoagulation to protect patients with high-risk AF and HHT from cerebral embolic strokes.

Aims: We evaluated the effect of pulmonary vein (PV) anatomical characteristics on PV isolation (PVI) and long-term efficacy of ablation with phased radiofrequency (RF) energy and pulmonary vein ablation catheter (PVAC) multi-electrode catheter., Methods and Results: Before the procedure, PV anatomy was visualized by magnetic resonance imaging (MRI). Consecutive patients with paroxysmal atrial fibrillation were treated with the PVAC with successful acute isolation. Follow-up was performed at 3, 6, and 12 months with electrocardiogram and 7-day Holter recording at 6 and/or 12 months. Symptomatic patients received additional event recording. In 110 patients a pre-procedure cardiac MRI was performed. Ninety-seven (88%) had a separate left superior PV and separate left inferior PV, all patients had a separate right superior PV and separate right inferior PV. Fourteen (13%) had a left PV with common trunk and 27 (25%) had a separate right middle PV (RMPV). After a follow-up of 1 year, 57 of 110 (52%) patients were free of AF without anti-arrhythmic drug. No specific anatomical variable that was related to long-term failure could be found. There was a trend for patients with larger veins (>24 mm) or separate RMPV to have a lower efficacy. The number of applications per vein or procedure did not influence long-term outcome., Conclusions: In patients who have undergone PVI with phased RF energy and PVAC multi-electrode ablation, long-term efficacy is not significantly affected by PV anatomy or number of applications, although a trend for reduced efficacy is seen for PV with diameter >24 mm, and presence of RMPV.

Objective: Percutaneous catheter pulmonary vein isolation (PVI) has been the preferred choice for invasive treatment of symptomatic, drug-refractory lone atrial fibrillation (AF). Incomplete ablation lines, procedure-related morbidity and long-term success remain, however, a problem. A minimally invasive surgical approach can provide an attractive and secure alternative. Surgery offers an epicardial, bipolar approach under direct vision, but the invasiveness of surgery remains a problem. Therefore, we developed a completely thoracoscopic procedure. The objective of this study was to assess the feasibility, safety and effectiveness of a completely thoracoscopic surgical procedure to cure lone AF., Methods: Bilateral 'video-assisted thoracoscopy' was performed to isolate the bilateral pairs of pulmonary veins using bipolar RF-energy, to ablate the ganglionic plexus (GP) and to amputate the left atrial appendage. Preoperative, in-hospital and follow-up data were collected for our first 30 patients., Results: AF was paroxysmal in 63%, persistent in 27% and permanent in 10% of cases. The mean (+ or - SD) left atrial diameter was 42.1 + or - 7.4mm and the mean duration of AF was 79.0 + or - 63.9 months. Freedom from AF was obtained in 77% of the patients during a mean follow-up of 11.6 months. Forty-three percent of the patients had previously undergone a percutaneous PVI and were all free from AF during follow-up. Mean operation time was 137.4 + or - 24.7 min. All patients were extubated in the operating room and left the recovery room within 12 h. The mean hospital stay was 5.1 + or - 1.8 days. Two patients ultimately underwent a median sternotomy. No CVAs or pacemaker implantation were identified and none of the patients died., Conclusion: We report our initial experience of a completely thoracoscopic PVI with GP-ablation and amputation of the left atrial appendage and demonstrate that the procedure is feasible, safe and effective for the treatment of lone AF., (Copyright 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.)

Aims: Left atrial (LA) stretch-associated electrophysiological changes in patients with mitral stenosis (MS) predispose to atrial fibrillation. We hypothesized that the normalization of the pressure gradient by percutaneous transvenous mitral balloon valvotomy (PTMV) affects LA but not right atrial (RA) conduction, depending on the site of stimulation. Because direction-dependent (asymmetric) changes of conduction may contribute to arrhythmogenesis, we assessed conduction symmetry in MS patients and tested whether it is restored by PTMV., Methods and Results: In nine patients with MS, atrial effective refractory period and local activation times (ATs) were determined during stimulation before and after PTMV, with up to four decapolar catheters (LA and RA). Eight patients with ventricular pre-excitation served as controls. ATs at basic cycle length were similar before and after PTMV. With stimulation from either atrium, they were about 45 ms in the ipsilateral atrium and about 115 ms in the contralateral atrium. With premature stimulation, ATs increased dramatically. The shortest ATs were found in the RA with RA stimulation (78 +/- 9 and 80 +/- 6 ns, before and after PTMV). PTMV caused a shortening in LA-ATs (following LA stimulation) from 118 +/- 14 to 82 +/- 5 ms (before and after; P < 0.05). Asymmetry in conduction properties was therefore normalized by PTMV. PTMV led to a decrease in RA-ATs (following LA stimulation) from 196 +/- 11 to 174 +/- 13 ms (P < 0.02). In addition, following RA stimulation, the dispersion in ATs in the LA decreased significantly by PTMV (from 66 +/- 10 to 34 +/- 7 ms; P < 0.02)., Conclusion: MS is associated with LA conduction delay, increased LA dispersion of conduction, and conduction asymmetry. These changes are immediately reversible by PTMV.

Introduction: The aim of this study is to characterize ablation lesions using varying ratios of bipolar:unipolar energy and to show the feasibility of a circular decapolar pulmonary vein ablation catheter (PVAC) to create transmural lesions in an in vivo porcine superior vena cava (SVC) model., Methods and Results: Ablations were performed on (1) isolated blocks of bovine myocardium, (2) thigh muscle preparations (4 pigs), and (3) the junction between SVC and right atrium (6 pigs). Radiofrequency (RF) energy was delivered simultaneously to all electrodes (target temperature 60 degrees C, maximum power 10 W/electrode) with various ratios of bipolar:unipolar energy. (1) In vitro PVAC resulted in circumscript lesions. Changing RF energy mode from unipolar only to bipolar:unipolar 1:1, 2:1 and 4:1 and bipolar only decreased lesion depth significantly (6.7 +/- 0.2 vs. 5.0 +/- 0.2, 4.1 +/- 0.3, 3.6 +/- 0.1 and 3.1 +/- 0.1 mm, P < 0.001). (2) Similar results were obtained in vivo (thigh muscle) showing less deep lesions with more bipolar energy modes (e.g., 5.4 +/- 1.3 for unipolar only vs. 4.1 +/- 0.8 mm for bipolar only, P < 0.05). (3) Ablation at the SVC did not result in device-related complications. All animals survived and were sacrificed after 7 +/- 1 days except for one pig, which died immediately postoperatively from an unknown cause. Macroscopy and microscopy showed circumferential transmural SVC lesions., Conclusions: Temperature-controlled, power-limited RF energy with the PVAC is feasible for creating circumferential transmural lesions (SVC) that sometimes extended to neighboring structures. Lesion depth can be titrated by varying the bipolar:unipolar energy ratio. This novel ablation system paves the way for single-catheter ablation of AF.

Aims: To determine whether risk stratification tests can predict serious arrhythmic events after acute myocardial infarction (AMI) in patients with reduced left ventricular ejection fraction (LVEF < or = 0.40)., Methods and Results: A total of 5869 consecutive patients were screened in 10 European centres, and 312 patients (age 65 +/- 11 years) with a mean LVEF of 31 +/- 6% were included in the study. Heart rate variability/turbulence, ambient arrhythmias, signal-averaged electrocardiogram (SAECG), T-wave alternans, and programmed electrical stimulation (PES) were performed 6 weeks after AMI. The primary endpoint was ECG-documented ventricular fibrillation or symptomatic sustained ventricular tachycardia (VT). To document these arrhythmic events, the patients received an implantable ECG loop-recorder. There were 25 primary endpoints (8.0%) during the follow-up of 2 years. The strongest predictors of primary endpoint were measures of heart rate variability, e.g. hazard ratio (HR) for reduced very-low frequency component (<5.7 ln ms(2)) adjusted for clinical variables was 7.0 (95% CI: 2.4-20.3, P < 0.001). Induction of sustained monomorphic VT during PES (adjusted HR = 4.8, 95% CI, 1.7-13.4, P = 0.003) also predicted the primary endpoint., Conclusion: Fatal or near-fatal arrhythmias can be predicted by many risk stratification methods, especially by heart rate variability, in patients with reduced LVEF after AMI.

Background: Pulmonary vein (PV) isolation for ablation of atrial fibrillation (AF) remains a complex and lengthy procedure., Objective: The purpose of this study was to evaluate the feasibility and safety of a novel multielectrode catheter that delivers duty-cycled bipolar and unipolar radiofrequency (RF) energy., Methods: Patients eligible for catheter ablation of paroxysmal AF after screening with magnetic resonance imaging and transesophageal echocardiography were included in the study. A decapolar (3-mm electrode, 3-mm spacing, 25-mm diameter), circular, over-the-wire mapping and ablation catheter was deployed in the antrum of each PV. Ablation was performed with 60-second, 60 degrees C applications of duty-cycled bipolar/unipolar RF in a 4:1 ratio simultaneously at all selected electrode pairs until local activity was no longer observed. At 6 months, 7-day Holter monitoring was performed to determine freedom from AF without use of antiarrhythmic drugs., Results: In 98 patients (mean age 59 +/- 9 years), the PV ablation catheter was used for ablation of 369 veins (20 common left antra). All targeted veins (100%) were isolated as confirmed by the absence of potentials in the ostium either by PV ablation catheter or Lasso mapping. Mean number of RF applications was 27 +/- 7, total procedural time 84 +/- 29 minutes, and fluoroscopy time 18 +/- 8 minutes. Follow-up after 6 months without antiarrhythmic drugs showed freedom from AF in 83% of patients. No procedure-related complications were observed., Conclusion: PV isolation by duty-cycled bipolar/unipolar low-power RF energy through a circular, decapolar catheter can be achieved safely and efficiently, with good efficacy at 6 months.

Isolated left ventricular noncompaction is a rare cardiomyopathy that is often not recognised. So far, it is not well established how best to manage this abnormality. We describe a patient in whom the diagnosis of isolated left ventricular noncompaction was made after presentation with a subacute myocardial infarction. Because of nonsustained ventricular tachycardias during hospitalisation, which were inducible and deteriorated into ventricular fibrillation on electrophysiological examination after coronary artery bypass grafting, he received an implantable defibrillator. Whether the ventricular tachycardias were due to the myocardial infarction or to the noncompacted myocardium remains uncertain. (Neth Heart J 2007;15:109-11.).

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.

Objectives: We studied the persistence of favorable outcome, the occurrence of new atrial arrhythmias, and sinus node dysfunction in patients who underwent the maze III procedure., Methods: Preoperative, in-hospital, and follow-up data of 203 patients who underwent the maze III procedure between June 1993 and June 2003 were collected. A total of 139 patients underwent the maze procedure for lone atrial fibrillation, and 64 patients underwent the maze procedure and concomitant cardiac surgery., Results: There was no 30-day postoperative mortality. During a mean follow-up of 4.0 +/- 2.6 years, 12 patients (6%) died (2 cardiac related). At the end of follow-up, freedom from supraventricular arrhythmias was 80% for the lone atrial fibrillation group and 64% for the concomitant atrial fibrillation group. Freedom from stroke during follow-up was 100% in the lone atrial fibrillation group and 97% in the concomitant group. Multivariate analysis revealed that rhythm at 1-year follow-up (P < .001; odds ratio 9.56, 95% confidence limits 3.92-23.31) and preoperative left atrium dimension (P = .028; odds ratio 1.06 for every millimeter, 95% confidence limits 1.01-1.12) were predictors of success at the end of follow-up., Conclusions: This study shows that the favorable results of the maze III procedure in terms of freedom from supraventricular arrhythmias persist in most patients for at least 4 years.

Background: Radiofrequency (RF) catheter ablation is highly effective with a low complication rate. However, lesions created by RF energy are irreversible, inhomogeneous, and therefore potentially proarrhythmic., Objectives: The aim of this study was to examine the magnitude and importance of long-term proarrhythmic effects of RF energy., Methods and Results: Between 1991 and 1995, 120 patients underwent RF ablation for atrioventricular nodal reentrant tachycardia (AVNRT). Patient data were collected by contacting patients and/or filling out a questionnaire, and medical files were screened for recurrent, documented arrhythmias, pharmacological treatment, and repeated EP study. Referring cardiologists were asked about recurrences of tachyarrhythmias. Fourteen patients (11%) were lost to follow-up. During a mean follow-up of 10 years, six patients died. Recurrences of AVNRT were not any more observed after 3 years after ablation. A total of 29 patients (24%) suffered from new arrhythmias, 6 from type 1 atrial flutter, 6 from atrial tachycardia, 9 from atrial fibrillation, and finally 16 from symptomatic premature atrial contractions (PACs), needing medical treatment or a combination of these arrhythmias. Nine patients underwent pacemaker implantation, 4 after developing procedural atrioventricular (AV) conduction disturbances, 2 after His ablation for permanent atrial fibrillation, 1 patient for sick sinus syndrome, and another 2 patients after developing late AV block, respectively, 7 and 9 years after ablation., Conclusion: During long-term follow-up after RF ablation for AVNRT, no AVNRT recurrences were observed, but 29 patients (24%) suffered from new arrhythmias or late AV block. This potential proarrhythmic effect of RF energy promotes the application of alternative energy sources for ablative therapies for cardiac arrhythmias.

Background: During a catheter ablation procedure for selective electrical isolation of pulmonary vein (PV) ostia, the size of these ostia is usually estimated using fluoroscopic angiography. This measurement may be misleading, however, because only the projected supero/inferior ostium diameters can be measured. In this study, we analyzed 3-dimensional magnetic resonance angiographic (MRA) images to measure the minimal and maximal cross-sectional diameter of PV ostia in relation to the diameter that would have been projected on fluoroscopic angiograms during a catheter ablation procedure., Methods and Results: In 42 patients with idiopathic atrial fibrillation who were scheduled for selective electrical isolation of PV ostia, the minimal and maximal diameters of these ostia were measured from 3-dimensional MRA images. Thereafter, these images were oriented in a 45 degrees right or left anterior oblique direction and the projected diameter of the PV ostia were measured again. The average ratio between maximal and minimal diameter was 1.5+/-0.4 for the left and 1.2+/-0.1 for the right pulmonary vein ostia. Because of the orientation and oval shape of especially the left pulmonary vein ostia, their minimal diameters were significantly smaller than the projected diameters., Conclusion: Pulmonary vein ostia, especially those at the left, are oval with the short axis oriented approximately in the antero/posterior direction. Consequently, PV ostia may sometimes be very narrow despite a rather normal appearance on angiographic images obtained during a catheter ablation procedure.

A 56-year-old woman without structural heart disease had an ECG typical of Brugada syndrome. Syncope occurred due to monomorphic VT with left bundle branch block (LBBB) morphology. At electrophysiological study, VT with the same morphology was inducible.

Exertional heat stroke may be complicated by mild neurological deficits, usually with complete convalescence. This may be associated with metabolic disorders inherent to hyperthermia such as a marked coagulopathy. We report a case of a previously healthy 20 year old male who died in the course of exertional heat stroke complicated by intracerebral hemorrhage.