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Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Yet tools and techniques used for confirmation of PVI vary greatly, and it is unclear whether the use of any particular combination of tools and techniques provides greater sensitivity for identifying gaps periprocedurally. It has been suggested the use of a high-density mapping catheter, which enables simultaneous recording of adjacent bipolar EGMs in two directions, may provide improved sensitivity for gap identification. Anonymized, acute procedural data was prospectively collected in AF ablation cases utilizing various workflows for confirmation of PVI. Post-hoc analysis was performed to evaluate the incidence of gaps detected by different diagnostic catheter technologies, including a high-density mapping catheter and circular mapping catheters (CMCs), and common techniques such as pacing the ablation lines. A total of 139 cases were included across three subgroup analyses: 99 cases were included in an indirect comparison of three mapping catheter technologies, revealing gaps in 36.7%, 38.9%, and 81.8% of cases utilizing a 10-pole CMC, 20-pole CMC, and a high-density mapping catheter, respectively; a direct comparison of diagnostic catheter technologies in 18 cryoballoon ablation cases revealed residual gaps in 22.2% of patients identified by high-density mapping which were missed previously with the use of a 3.3F CMC; in 22 cases utilizing a technique of pacing the ablation lines, high-density mapping identified residual gaps in 68.2% of patients. This proof of concept analysis demonstrated that the use of a high-density catheter which records orthogonal bipoles simultaneously, appears to improve acute detection of gaps in PVI lines relative to other commonly utilized techniques and technologies. The long-term impact of ablating these concealed gaps remains unclear. Further study, including direct comparison of diagnostic catheter technologies in a randomized setting with long-term followup, is warranted.

Objectives The purpose of this study was to investigate the efficacy safety of the novel cryoballoon device (Arctic Front, Cryocath, Quebec, Canada). Background Antral pulmonary vein (PV) ablation with radiofrequency energy is widely used as a strategy for catheter ablation of paroxysmal atrial fibrillation (PAF). A novel double lumen cryoballoon catheter was designed for circumferential pulmonary vein isolation (PVI) with the cryoablation technique. Methods We consecutively enrolled 346 patients with symptomatic, drug refractory paroxysmal (n = 293) or persistent (n = 53) atrial fibrillation (AF). In all patients, PVI of all targeted PVs was the therapeutic aim. The primary end points of this nonrandomized study were: 1) acute isolation rate of targeted PV; and 2) first electrocardiogram-documented recurrence of AF. The secondary end point was occurrence of PV stenosis or atrio-esophageal fistula. Results The 1,360 of 1,403 PVs (97%) were targeted with balloons or balloons in combination with the use of Freezor Max (Cryocath). We found that ablation with the cryoballoon resulted in maintenance of sinus rhythm in 74% of patients with PAF and 42% of patients with persistent AF. No PV narrowing occurred. The most frequent complication was right phrenic nerve palsy observed during cryoballoon ablation at the right superior PV. Conclusions Pulmonary vein isolation with a new cryoballoon technique is feasible. Sinus rhythm can be maintained in the majority of patients with PAF by circumferential PVI using a cryoballoon ablation system. Cryoablation was less effective in patients with persistent AF than in patients with PAF.

Aims This study investigates the influence of cardiac resynchronisation therapy (CRT) on sleep disordered breathing (SDB) in patients with severe heart failure (HF). Methods and results Seventy-seven patients with HF (19 females; 62.6±10 years) eligible for CRT were screened for presence, type, and severity of SDB before and after CRT initiation (5.3±3 months) using cardiorespiratory polygraphy. NYHA class, frequency of nycturia, cardiopulmonary exercise, 6-minute walking test results, and echocardiography parameters were obtained at baseline and follow-up. Central sleep apnoea (CSA) was documented in 36 (47%), obstructive sleep apnoea (OSA) in 26 (34%), and no SDB in 15 (19%) patients. CRT improved clinical and haemodynamic parameters. SDB parameters improved in CSA patients only (apnoea hypopnoea index: 31.2±15.5 to 17.3±13.7/h, p

Objective: To test the hypothesis that atrial fibrillation (AF) is associated with changes in the expression of connexins 40 and 43 in the left atrium with more pronounced changes in mitral valve disease than in lone AF. Methods: Protein concentrations of connexin 40 and connexin 43 were analysed in left atrial tissue of patients undergoing cardiac surgery. One group of patients had lone AF (n = 41), one group had AF and mitral valve repair (n = 36), and one group in sinus rhythm served as controls (n = 15). Results: Western blot analysis of connexin 40 and connexin 43 expression showed an increase of both gap junctional proteins (connexin 43 > connexin 40) in patients with AF of all forms compared with patients in sinus rhythm (p = 0.01 and p = 0.011, respectively). Subgroup analysis showed increased concentrations of connexin 40 in lone AF and AF with mitral valve disease compared with sinus rhythm (p = 0.06 and p = 0.029, respectively), whereas the same analysis for connexin 43 reached significance only in the mitral valve disease group (p = 0.031). No differences in connexin 40 and connexin 43 expression were detectable between lone AF and AF with mitral valve disease. Within the groups connexin 40 and connexin 43 expression did not differ between patients with paroxysmal AF and patients with chronic AF. Conclusion: The present study shows for the first time that AF can induce changes in the left atrium with increased connexin expression. Furthermore, no systematic differences between patients with paroxysmal and chronic AF were detected.

Objectives: The aim of this study was to analyze different anatomic mapping approaches for successful ablation of outflow tract tachycardia with R/S transition in lead V3.Background: Idiopathic ven...

Abstract —This study presents an analysis of the expression of type VIII collagen mRNA in response to cholesterol diet and balloon injury in the rabbit iliac artery. The design of the animal experiments was as follows: 28 male New Zealand White rabbits were divided into the 3 different treatment groups. Group 1 received regular chow; group 2 was fed with a 1% cholesterol diet for 6 weeks and normal chow for 5 weeks; and group 3 underwent balloon injury, then 6 weeks of a 1% cholesterol diet, which was followed by 5 weeks of normal chow. The expression pattern of type VIII collagen mRNA was compared with that of the fibrillar collagen types I and III, transforming growth factor-β1, a factor known to exert the most potent stimulatory effect on collagen synthesis in vitro, and matrix metalloproteinase 1, a collagen-degrading enzyme. The cholesterol diet resulted in an upregulation of type VIII collagen, fibrillar collagens, transforming growth factor-β1, and matrix metalloproteinase I in the adventitia. Although the number of type VIII collagen mRNA–expressing cells in the media increased, no significant difference in overall expression levels was detectable by northern blot analysis. The ratio of medial smooth muscle cells expressing type VIII collagen mRNA to those expressing type I and type III collagen mRNA (CVIII:CI:CIII) changed from 1:1.88:0.03 in the normal media to 1:0.78:0.29. When cholesterol feeding was preceded by balloon injury, type VIII collagen mRNA expression concomitant with the fibrillar collagens was further upregulated over and above that level reported after cholesterol diet alone. In general, low levels of transforming growth factor-β1 mRNA correlated with high expression of matrix metalloproteinase I. Our study indicates that a cholesterol diet resulted in a balanced reorganization of the collagen composition but did not result in marked collagen accumulation. This may provide an extracellular environment that favors migration and proliferation processes during early atherogenesis. It also demonstrates that type VIII collagen is highly expressed and deposited at later stages, and this may be linked to processes such as tissue reorganization during vascular repair and plaque stabilization.

The purpose of this study was to investigate the efficacy safety of the novel cryoballoon device (Arctic Front, Cryocath, Quebec, Canada).Antral pulmonary vein (PV) ablation with radiofrequency energy is widely used as a strategy for catheter ablation of paroxysmal atrial fibrillation (PAF). A novel double lumen cryoballoon catheter was designed for circumferential pulmonary vein isolation (PVI) with the cryoablation technique.We consecutively enrolled 346 patients with symptomatic, drug refractory paroxysmal (n = 293) or persistent (n = 53) atrial fibrillation (AF). In all patients, PVI of all targeted PVs was the therapeutic aim. The primary end points of this nonrandomized study were: 1) acute isolation rate of targeted PV; and 2) first electrocardiogram-documented recurrence of AF. The secondary end point was occurrence of PV stenosis or atrio-esophageal fistula.The 1,360 of 1,403 PVs (97%) were targeted with balloons or balloons in combination with the use of Freezor Max (Cryocath). We found that ablation with the cryoballoon resulted in maintenance of sinus rhythm in 74% of patients with PAF and 42% of patients with persistent AF. No PV narrowing occurred. The most frequent complication was right phrenic nerve palsy observed during cryoballoon ablation at the right superior PV.Pulmonary vein isolation with a new cryoballoon technique is feasible. Sinus rhythm can be maintained in the majority of patients with PAF by circumferential PVI using a cryoballoon ablation system. Cryoablation was less effective in patients with persistent AF than in patients with PAF.

Increased expression of connexin43 gap junctions in smooth muscle cells (SMC) is implicated in the response to primary arterial injury and in the early stages of human coronary atherosclerosis, but the relevance of these findings to restenosis is unknown. Here we investigated the expression of connexin43 gap junctions in restenotic aortas of cholesterol-fed double injured rabbits. Immunofluorescence confocal microscopy was used to evaluate temporal and spatial expression patterns and to characterize the major expressing cell type. Parallel studies were conducted by electron microscopy, in situ hybridization and Northern blot analysis. Connexin43 gap junctions- and connexin43 mRNA-expressing cells were abundant in the media of non-injured control aorta. Following primary injury and 6 weeks cholesterol diet, connexin43 gap junctions were found distributed throughout the primary intimal layer; although medial expression was reduced, the overall mRNA expression level remained similar to that of non-injured controls. After secondary injury, no major change in distribution pattern of connexin43 gap junctions occurred up to day 10, when marked neointimal labeling was observed. This overall pattern persisted, though with some diminution, at later stages. On the mRNA level total connexin43 mRNA expression declined to about 40% of control values within 4 days after secondary injury (P < 0.05), but subsequently increased four-fold, attaining levels double that of non-injured controls in the 10-day group (P < 0.005 versus control and 4 days). At later stages mRNA expression levels returned to values similar to those of non-injured controls. At all stages, connexin43 gap junctions were localized to the SMC, not to macrophages. We conclude that the enhanced gap junction formation may contribute to the coordination of the response of SMC after secondary injury, particularly in the early phase of restenosis.

AIMS In 1999 the consensus statement "living anatomy of the atrioventricular junctions" was published. With that new nomenclature the former posteroseptal accessory pathway (APs) are termed paraseptal APs. The aim of this study was to identify ECG features of manifest APs located in this complex paraseptal space. METHODS AND RESULTS ECG characteristics of all patients who underwent radiofrequency ablation of an AP during a 3 year period were analyzed. Of the 239 patients with one or more APs, 30 patients had a paraseptal AP with preexcitation. Compared to APs within the coronary sinus (CS) or the middle cardiac vein (MCV) the right sided paraseptal APs significantly more often showed an isoelectric delta wave in lead II and/or a negative delta wave in aVR. The left sided paraseptal APs presented a negative delta wave in II significantly more often compared to the right sided APs. CONCLUSIONS According to the site of radiofrequency ablation, paraseptal APs are classified into 4 subgroups: paraseptal right, paraseptal left, inside the CS or inside the MCV. Subtle differences in preexcitation patterns of the delta wave as well as of the QRS complex exist. However, the definitive localization of APs remains reserved to the periinterventional intracardiac electrogram analysis.

Objectives The aim of this study was to analyze trigger activity in the long-term follow-up after left atrial (LA) linear ablation. Background Interventional strategies for curative treatment of atrial fibrillation (AF) are targeted at the triggers and/or the maintaining substrate. After substrate modification using nonisolating linear lesions, the activity of triggers is unknown. Methods With the LA linear lesion concept, 129 patients were treated using intraoperative ablation with minimal invasive surgical techniques. Contiguous radiofrequency energy-induced lesion lines involving the mitral annulus and the orifices of the pulmonary veins without isolation were placed under direct vision. Results After a mean follow-up of 3.6 ± 0.4 years, atrial ectopy, atrial runs, and reoccurrence of AF episodes were analyzed by digital 7-day electrocardiograms in 30 patients. Atrial ectopy was present in all patients. Atrial runs were present in 25 of 30 patients (83%), with a median number of 9 runs per patient/week (range 1 to 321) and a median duration of 1.2 s/run (range 0.7 to 25), without a significant difference in atrial ectopy and atrial runs between patients with former paroxysmal (n = 17) or persistent AF (n = 13). Overall, 87% of all patients were completely free from AF without antiarrhythmic drugs. Conclusions A detailed rhythm analysis late after specific LA linear lesion ablation shows that trigger activity remains relatively frequent but short and does not induce AF episodes in most patients. The long-term success rate of this concept is high in patients with paroxysmal or persistent AF.

The aim of this study was to analyze different anatomic mapping approaches for successful ablation of outflow tract tachycardia with R/S transition in lead V(3).Idiopathic ventricular tachycardia can originate from different areas in the outflow tract, including the right and left ventricular endocardium, the epicardium, the pulmonary artery, and the aortic sinus of Valsalva. Although electrocardiographic criteria may be helpful in predicting the area of origin, sometimes the focus is complex to determine, especially when QRS transition in precordial leads is in V(3).We analyzed surface electrocardiograms of 33 successfully ablated patients with outflow tract tachycardia: 20 from the right ventricular outflow tract (RVOT) and 13 from different sites. The R/S transition was determined, and the different anatomic approaches needed for successful catheter ablation were studied.Overall, R/S transition in lead V(3) was present in 19 (58%) of all patients. In these patients, mapping was started and successfully completed in the RVOT in 11 of 19 (58%) patients. The remaining eight patients with R/S transition in lead V(3) needed five additional anatomic accesses for successful ablation: from the left ventricular outflow tract (n = 3), aortic sinus of Valsalva (n = 2), coronary sinus (n = 1), the epicardium via pericardial puncture (n = 1), and the trunk of the pulmonary artery (n = 1), respectively.A R/S transition in lead V(3) is common. In patients with outflow tract tachycardia with R/S transition in lead V(3), a stepwise endocardial and epicardial mapping through up to six anatomic approaches can lead to successful radiofrequency catheter ablation.

We sought to analyze the time course of atrial fibrillation (AF) episodes before and after circular plus linear left atrial ablation and the percentage of patients with complete freedom from AF after ablation by using serial seven-day electrocardiograms (ECGs).The curative treatment of AF targets the pathophysiological corner stones of AF (i.e., the initiating triggers and/or the perpetuation of AF). The pathophysiological complexity of both may not result in an "all-or-nothing" response but may modify number and duration of AF episodes.In patients with highly symptomatic AF, circular plus linear ablation lesions were placed around the left and right pulmonary veins, between the two circles, and from the left circle to the mitral annulus using the electroanatomic mapping system. Repetitive continuous 7-day ECGs administered before and after catheter ablation were used for rhythm follow-up.In 100 patients with paroxysmal (n = 80) and persistent (n = 20) AF, relative duration of time spent in AF significantly decreased over time (35 +/- 37% before ablation, 26 +/- 41% directly after ablation, and 10 +/- 22% after 12 months). Freedom from AF stepwise increased in patients with paroxysmal AF and after 12 months measured at 88% or 74% depending on whether 24-h ECG or 7-day ECG was used. Complete pulmonary vein isolation was demonstrated in20% of the circular lesions.The results obtained in patients with AF treated with circular plus linear left atrial lesions strongly indicate that substrate modification is the main underlying pathophysiologic mechanism and that it results in a delayed cure instead of an immediate cure.

Implantable defibrillators (ICDs) are the treatment of first choice concerning survived sudden cardiac death (SCD) or symptomatic ventricular tachycardias (VT). Technical progress now offers telemetric performed interrogations and controls including information about the system status, episodes detected and treated via so called home monitoring (HM). Target of this work was to bundle first results and experience from single cases from a systematic clinical investigation (= home - ICD trial) and define a model for an economic research on the cost-effectiveness ratio of the treatment. Till today 228 patients could be included in the trial. On the economic question a Markov-chain model with three abstracted types of complications and three layers of economic benefit could be set up and is shared for discussion.

Aims We describe a new strategic stepwise mapping approach for fast and accurate identification and ablation of ectopic atrial foci using an electroanatomic mapping system. Methods and Results Mapping procedures started with the acquisition of four points at the superior/septal part of the tricuspid annulus. According to this activation sequence, maps were continued towards the right atrial free wall if relatively early activation was shown at the superior part of the initial map or towards the triangle of Koch and, if necessary, to the left atrium, in cases of relatively early activation at the septum. High density mapping and detailed electrogram analysis only of the target area allowed identification and ablation of 34 foci in 30 of the 32 studied consecutive patients. A small number of mapping points were sufficient within a procedure time of 90±41min for right 148±68min and for left sided foci and a total fluoroscopy time of 9·6±7·2min and 24·8±16·4min respectively. Sixteen foci were located at the right free wall, eight at the left free wall, and 10 at the right or left side of the septum. Conclusion Strategical electroanatomical mapping with fast identification of the area of tachycardia origin and high density mapping only of this target area allowed fast and successful localization and ablation of right and left free wall and septal ectopic atrial foci. Copyright 2002 The European Society of Cardiology. Published by Elsevier Science Ltd. All rights reserved.

Background Due to the investigative nature of AF catheter ablation, currently only highly symptomatic patients are treated. Remarkable success rates have been reported repeatedly. However, the follow up strategies measuring that outcome are largely based on symptomaticity. Therefore the present study aimed on analyzing the perception of AF in 114 pts. before and after a left atrial catheter ablation using the CARTO System. Methods A digital 7-d-ECG was recorded prior to ablation, right after ablation, after 3 months, after 6 months and after 12 months. During the 7-d-ECG the pts. hourly registered quality and duration of any symptoms in a certain patient's log. Palpitation, dyspnoea, dizziness and chest pain were taken as surrogates of AF. Subsequently the amount of time with symptomatic AF, asymptomatic (ASYM) AF, symptomatic SR and ASYM SR was measured. Additionally the individual AF episode was classified as either symptomatic or ASYM. Results For more than 75000 hours of ECG recording symptoms and rhythm were correlated. Prior ablation 54% of the time in AF and 22% of the AF episodes were ASYM. After ablation the proportion of ASYM AF episodes increased from 22% to 53% of all AF episodes. Watching the individual patient ASYM AF was common in 65% of all pts. with AF before and after catheter ablation. Nevertheless, the percentage of pts. with only ASYM AF during the 7-d-ECG increased from 10% prior ablation to 36% 6 months after ablation. Conclusions Pts. with highly symptomatic AF also exhibit a substantial amount of ASYM arrhythmia (54% of AF time, 22% of AF episodes). After ablation the amount of ASYM AF increased, with half of the episodes being ASYM. Furthermore, 36% of the pts. with AF recurrences at the 6 months follow up were completely ASYM during that 7-d-ECG. Our data show, that a judgement on the efficacy of percutaneus AF ablation based on patient's symptoms substantially overestimates the success rate. Objective follow up strategies, applied in a close manner, are needed for a through measurement of the real outcome.

Purpose: Recognition of the phrenic nerve (PhN) course is helpful for avoiding complications during ablation. We evaluated the PhN route along the heart using electro-anatomical mapping (EAM). Methods: In 18 patients with atrial fibrillation (AF) undergoing pulmonary vein (PV) isolation, EAM of superior vena cava (SVC), right and left atria, and right pulmonary veins (PVs) was reconstructed using a CARTO system during sinus rhythm. The location of the PhN adjacent to the heart was defined as the site twitching of the diaphragm with pacing (5-10 voks) occurred, and that site was tagged on the EAM. Results: The PhN began at the upper limit and anterior aspect of the SVC and twisted down to the posterior aspect of the right atrium near the sinus node in 14 patients (78%), or it was located at the postero-lateral aspect of whole SVC in 4 patients (22%). In most cases (89%), the PhN could be captured at the anterior aspect of the right superior PV (RSPV) which was 8.14-3 mm inside RSPV ostium, whereas it could not be captured from the right inferior PV in any patients or from the lower right atrium in 11 patients (61%).