Search

. (J Cardiovasc Electrophysiol, Vol. 22, pp. 516-520 May 2011) [ABSTRACT FROM AUTHOR]

Autonomic Blockade During Atrial Fibrillation. Introduction: The influence of the autonomic nervous system on the pathogenesis of complex fractionated atrial electrograms (CFAE) during atrial fibrillation (AF) is incompletely understood. This study evaluated the impact of pharmacological autonomic blockade on CFAE characteristics. Methods and Results: Autonomic blockade was achieved with propanolol and atropine in 29 patients during AF. Three-dimensional maps of the fractionation degree were made before and after autonomic blockade using the Ensite Navx® system. In 2 patients, AF terminated following autonomic blockade. In the remaining 27 patients, 20,113 electrogram samples of 5 seconds duration were collected randomly throughout the left atrium (10,054 at baseline and 10,059 after autonomic blockade). The impact of autonomic blockade on fractionation was assessed by blinded investigators and related to the type of AF and AF cycle length. Globally, CFAE as a proportion of all atrial electrogram samples were reduced after autonomic blockade: 61.6 ± 20.3% versus 57.9 ± 23.7%, P = 0.027. This was true/significant for paroxysmal AF (47 ± 23% vs 40 ± 22%, P = 0.003), but not for persistent AF (65 ± 22% vs 62 ± 25%, respectively, P = 0.166). Left atrial AF cycle length prolonged with autonomic blockade from 170 ± 33 ms to 180 ± 40 ms (P = 0.001). Fractionation decreases only in the 14 of 27 patients with a significant (>6 ms) prolongation of the AF cycle length (64 ± 20% vs 59 ± 24%, P = 0.027), whereas fractionation did not reduce when autonomic blockade did not affect the AF cycle length (58 ± 21% vs 56 ± 25%, P = 0.419). Conclusions: Pharmacological autonomic blockade reduces CFAE in paroxysmal AF, but not persistent AF. This effect appears to be mediated by prolongation of the AF cycle length. (J Cardiovasc Electrophysiol, Vol. pp. 766-772, July 2010) [ABSTRACT FROM AUTHOR]

Objectives: This multicenter study sought to evaluate the long-term follow-up of patients ablated for idiopathic ventricular fibrillation (VF). Background: Catheter ablation of idiopathic VF that targets ventricular premature beat (VPB) triggers has been shown to prevent VF recurrences on short-term follow-up. Methods: From January 2000, 38 consecutive patients from 6 different centers underwent ablation of primary idiopathic VF initiated by short coupled VPB. All patients had experienced at least 1 documented VF, with 87% having experienced ≥2 VF episodes in the preceding year. Catheter ablation was guided by activation mapping of VPBs or pace mapping during sinus rhythm. Results: There were 38 patients (21 men) age 42 ± 13 years, refractory to a median of 2 antiarrhythmic drugs. Triggering VPBs originated from the right (n = 16), the left (n = 14), or both (n = 3) Purkinje systems and from the myocardium (n = 5). During a median post-procedural follow-up of 63 months, 7 (18%) of 38 patients experienced VF recurrence at a median of 4 months. Five of these 7 patients underwent repeat ablation without VF recurrence. Survival free of VF was predicted only by transient bundle-branch block in the originating ventricle during the electrophysiological study (p < 0.0001). The number of significant events (confirmed VF or aborted sudden death) was reduced from 4 (interquartile range 3 to 9) before to 0 (interquartile range 0 to 4) after ablation (p = 0.01). Conclusions: Ablation for idiopathic VF that targets short coupled VPB triggers is associated with a long-term freedom from VF recurrence. [Copyright &y& Elsevier]

Over the past decade, there has been an exponential increase in the number of catheter ablation procedures performed for atrial fibrillation (AF). While for paroxysmal AF, proximal pulmonary vein isolation is sufficient in the majority of cases, ablation of persistent and longstanding AF requires an extensive surgical-like procedure. This approach is correlated with a high rate of AF termination; however, this is achieved at the cost of at least one atrial tachycardia (AT) during the index procedure or during the patient's follow-up in the vast majority of cases. As these ATs are often multiple, complex, and frequently more symptomatic than AF, they constitute the last and frequently the most difficult step in ablation for patients with persistent AF. This review concentrates on the practical approaches to the treatment of AT in the context of AF ablation and provides an algorithm that aims at facilitating mapping and ablation strategies using conventional electrophysiological tools. [ABSTRACT FROM AUTHOR]

The article discusses the classification, incidence, and management of atrial tachycardias (AT) which occur during or after catheter ablation for atrial fibrillation. The conclusions are: conservative management for ATs is preferred; focal ATs often involve pulmonary vein tachycardias and localized reentry; and macroreentrant ATs usually include the mitral isthmus and left atrial roof.

Introduction: A patent foramen ovale (PFO) is located at the anterior and superior part of the anatomical interatrial septum, the area that is targeted during transseptal puncture. This study sought to investigate the impact of accessing the left atrium via a PFO on paroxysmal AF ablation. Methods: From March 2004, 203 patients (55 ± 11 years) underwent catheter ablation for paroxysmal AF (80 ± 71 months), with the endpoint being electrical isolation of all pulmonary veins (PV) and AF noninducibility. The presence of a PFO was determined by both transesophageal echocardiography and catheter probing. Procedural difficulty was evaluated by radiofrequency (RF), procedural, and fluoroscopic durations. Clinical follow-up was also investigated. Results: A PFO was detected in 27 patients (13%) by transesophageal echocardiography and in 22 additional patients (total 49 patients, 24%), by catheter probing (P < 0.001). A PFO was associated with longer total RF applications (57 ± 19 vs 51 ± 18 min, P = 0.04) and RF applications to isolate the PVs (42 ± 16 vs 35 ± 12 min, P = 0.001). Procedural and fluoroscopic times were unaffected. Seventy-three patients (36%) required a second procedure; there was no difference in the number of PV reconnections (1.3 vs 1.8 veins, P = NS). After a mean follow-up of 19 ± 9 months, 194/203 patients (96%) were free of AF, with no difference in patients in whom a PFO had been used. Conclusion: Although isolation of PVs is longer, overall procedural duration and success is not affected when using a PFO compared with a transseptal puncture. The presence of a PFO is underestimated by transesophageal echocardiography with brachial injection when compared with catheter probing. [ABSTRACT FROM AUTHOR]

Introduction: The coronary sinus (CS) is a complex structure comprising a mesh of circumferential muscular fibers with oblique connections to both atria. We describe further evidence for the clinical importance of CS arrhythmogenicity in maintaining atrial fibrillation (AF) in humans. Methods: Since January 2004, following a sequential approach, the CS and the inferior left atrium were ablated in 144 patients with symptomatic drug refractory AF. Patients were included for analysis when this step resulted in the electrical dissociation of the CS from both atria with restoration of sinus rhythm, but with continued arrhythmic activity in the CS. The electrophysiologic mechanism of the confined arrhythmia was considered as focal activity (automaticity or triggered activity) by the presence of electrograms spanning less than 75% of the cycle length in the CS. Results: After restoration of sinus rhythm, four male patients (3% of the patients, three persistent and one permanent AF) were identified in whom arrhythmia continued within the CS. Repetitive activity confined to the disconnected CS was inconsistent in occurrence, as well as in duration (1 sec to 15 min) and cycle length (from 158 to 380 ms). For all four patients, electrogram mapping of the entire CS was compatible with a focal mechanism. In two patients, bursts alternating with slow dissociated activity suggested automaticity. In one patient, local activity consistently coupled to the previous sinus beat favored triggered activity. Conclusions: This study provides evidence that the CS may be a potential source of focal rapid activity maintaining AF. [ABSTRACT FROM AUTHOR]

Introduction Methods and Results Conclusion Esophageal safety following radiofrequency (RF) left atrial (LA) linear ablation has not been established. To determine the esophageal safety profile of LA linear RF lesions, we performed systematic esophagogastroduodenoscopy in all patients with intraesophageal temperature rise (ITR) ≥ 38.5°C.Between December 2021 and July 2023, a total of 200 consecutive patients with atrial tachyarrhythmia (ATA) underwent linear ablation with posterior dome (roof or floor) or posterior mitral isthmus line transection. Patients with ITR ≥ 38.5°C were scheduled for esophageal endoscopy ~3 weeks after ablation. Patient and ATA characteristics, procedural parameters, endoscopy findings and ablation lesion data were collected and analyzed.One hundred thirty‐three out of 200 (67%) patients showed ITR ≥ 38.5°C during LA linear ablation. ITR (with maximal temperature of 45.7°C) was more frequently observed during floor line ablation (82% of cases). ITR was less observed during roof line ablation (34%) and posterior mitral isthmus ablation (4%). Endoscopy, performed in 115 patients after 24 ± 10 days, showed esophageal ulceration in four patients (two patients Kansas City classification [KCC] 2a and two patients KCC 2b). No patient showed esophageal perforation or fistula.Temperature rise during LA linear ablation is frequent and ulceration risk exists, particularly when floor line is performed. Safety measures are needed to avoid potential severe complications like esophageal perforation and fistula. [ABSTRACT FROM AUTHOR]

The article discusses the case of a 32-year-old man with a history of symptomatic persistent atrial fibrillation (AF) who was referred for a third catheter ablation procedure. The surface electrocardiogram reveals a consistent biphasic P wave in inferior leads with a pointed positive deflection followed by a late negative deflection. The case illustrates the evaluation of a conduction block created by a linear lesion joining the anterior mitral annulus to the right superior pulmonary vein.

The article presents a case of a 56-year-old man with a history of symptomatic drug refractory idiopathic persistent atrial fibrillation (AF) attended for catheter ablation. After proximal isolation of all pulmonary veins of the patient, electrogram-based The result suggests that the atrioventricular (AV) node was initially driven by a left atrial input and the return of sinus rhythm in both chambers led to the longer pulse rate (PR) interval.

The article presents a medical case of a 62-year-old man who developed atrial arrhythmia following first atrial fibrillation (AF) ablation, which carried for five years persistent for at least five months. At electrophysiological study, ablation was performed during AF with amiodarone continued to the time of the procedure. Two days after the ablation, he developed an atrial arrhythmia, which was considered as AF with relatively organized atrial activity in V1.

The article reports on the case of a 12 year old boy with complex congenital heart disease who presented to physicians with symptomatic incessant atrial flutter resistant to antiarrhythmic medication. A discussion of an electrophysiological study which was conducted on the patient is presented. The challenges of conducting ablation for arrhythmia in patients with congenital heart disease are discussed.

The article presents a case study in which a 36-year-old nan with paroxysmal atrial fibrillation (AF) and no structural heart disease received a third catheter ablation procedure that was performed in sinus rhythm. The usefulness of adenosine's proarrhythmic effect during AF catheter ablation is mentioned.

The article looks at a permanent atrial fibrillation patient referred for catheter ablation after showing signs of pulmonary edema. Procedures to treat arrhythmia, isolate all four pulmonary veins, and defragment both atria are discussed. Amiodarone was administered to treat atrial tachycardia. A quadripolar irritgated-tip ablation catheter was introduced to the ostium to repair the coronary sinus.

The article discusses the medical case of a 63-year-old man with symptomatic paroxysmal atrial fibrillation (AF) who was referred for catheter ablation. A quadripolar catheter was inserted to the coronary sinus and a circumferential mapping catheter were introduced to the left atrium (LA). The catheter was then advanced along the anterior until it finally disappeared, confirming an insulated dead-end pathway in the left atrium.

A letter to the editor is presented in response to the article "Rhythm Control Versus Rate Control for Atrial Fibrillation and Heart Failure" by D. Roy, M. Talajic and S. Nattel in the June 19, 2008 issue.

The article presents a case study of a 32-year-old woman with medical history of hemodynamically stable and regular tachycardia. It mentions use of electrocardiography analysis for diagnosis which revealed supraventricular tachycardia with an abnormal axis which can be caused by heart diseases. It also presents a fluoroscopic image of catheter positioning during the electrophysiology study in dextrocardia.

The superior vena cava (SVC) is well described as one of the most common non‐pulmonary vein (PV)—triggers for atrial tachyarrhythmias (ATA). In our study we evaluated a standardized approach for electrical isolation of the SVC from the right atrium using a horseshoe‐shaped lesion set with optimized and contiguous ostial RF lesions. The results are promising, demonstrating a very high rate of acute SVC isolation in a safe and time efficient manner (mostly less than 10 min). [ABSTRACT FROM AUTHOR]

Introduction: During left bundle branch area pacing (LBBAP) lead implantation, intermittent monitoring of unipolar pacing characteristics confirms LBB capture and can detect septal perforation. We aimed to demonstrate that continuous uninterrupted unipolar pacing from an inserted lead stylet (LS) is feasible and facilitates LBBAP implantation. Methods: Thirty patients (mean age 76 ± 14 years) were implanted with a stylet‐driven pacing lead (Biotronik Solia S60). In 10 patients (comparison‐group) conventional implantation with interrupted unipolar pacing was performed, with comparison of unipolar pacing characteristics between LS and connector‐pin (CP)‐pacing after each rotation step. In 20 patients (uninterrupted‐group) performance and safety of uninterrupted implantation during continuous pacing from the LS were evaluated. Results: In the comparison group, LS and CP‐pacing impedances were highly correlated (R2 = 0.95, p <.0001, bias 12 ± 37 Ω) with comparable sensed electrograms and paced QRS morphologies. In the uninterrupted group, continuous LS‐pacing allowed beat‐to‐beat monitoring of impedance and QRS morphology to guide implantation. This resulted in successful LBBAP in all patients, after a mean of 1 ± 0 attempts, with mean threshold 0.81 ± 0.4 V, median sensing 6.5 mV [IQR 4.4–9.5], and mean impedance 624 ± 101 Ω. Positive LBBAP‐criteria were seen in all patients with median paced QRS duration of 120 ms [IQR 112–152 ms] and median pLVAT 73 ms [IQR 68–80.5 ms]. No septal perforation occurred. Conclusion: Unipolar pacing from the LS allows accurate determination of pacing impedance and generates similar paced QRS morphologies and sensed electrograms to CP pacing. Continuous LS pacing allows real‐time monitoring of impedance and paced QRS morphology, which facilitates safe and successful LBBAP lead implantation. [ABSTRACT FROM AUTHOR]

Curative treatment of atrial fibrillation with catheter ablation is now a legitimate option for a large number of patients. In the last decade a tremendous amount has been discovered about this fascinating arrhythmia, yet there is still much that is understood. A number of different ablation strategies have been used including pulmonary vein isolation, targeting of fractionated electrograms, compartmentalising the atria with linear lesions and various combinations and modifications of these lesion sets. The optimal ablation strategy for both paroxysmal and long-lasting persistent atrial fibrillation is unknown. In this review the possible mechanisms underlying atrial fibrillation are examined along with the current catheter ablation techniques used in the treatment atrial fibrillation. [ABSTRACT FROM AUTHOR]

We report the case of a 71-year-old man with two atrial tachycardias evolving simultaneously and independently in two dissociated regions after extensive ablation for chronic atrial fibrillation. One tachycardia was a focal tachycardia originating from the right inferior pulmonary vein and activating the posterior left atrium with a 2:1 conduction block, while the other tachycardia was an atrial flutter circulating around the tricuspid annulus, activating the right atrium and the anterior wall of the left atrium. These two atrial tachycardias were successfully ablated prior to restoration of sinus rhythm. [ABSTRACT FROM AUTHOR]

Introduction: Recent studies have characterized drivers in persistent atrial fibrillation using automated algorithm detection with panoramic endocardial mapping by means of basket catheters. We aimed to identify repetitive atrial activation patterns (RAAPs) during ongoing atrial fibrillation (AF) based upon automated annotation of unipolar electrograms (EGMs) recorded with a high‐density regional endocardial contact mapping catheter. Methods: In 14 persistent AF patients, high‐resolution EGMs were recorded for 30 seconds at sequential PentaRay (Biosense Inc) positions covering the entire biatrial surface. All recordings were reviewed off‐line with dedicated software allowing automated annotation of the local activation time of the unipolar fibrillatory EGMs (CARTOFINDER; Biosense Inc). RAAPs were defined as a consistent activation pattern (for ≥3 consecutive beats) of either focal activity with centrifugal spread (RAAPfocal) or rotational activity across the PentaRay splines spanning the AF cycle length (RAAProtational). Results: A total of 498 PentaRay recordings were analyzed (35.6 ± 7.6 per patient). The number of PentaRay recordings displaying RAAP was 9.8 ± 3.1 per patient (range = 3‐15), of which 2.4 ± 2.4 RAAProtational (range = 0‐7), and 7.4 ± 4.4 RAAPfocal (range = 1‐13). 77% of RAAPs portrayed focal firing. The median number of repetitions per 30 second recording was 11 (range = 3‐225) per recording. RAAPs were observed both in the right atrium (RA) (35%) and left atrium (LA) (65%), with the majority being near the left PVs/appendage (35% of all RAAPs) and the superior vena cava/right appendage (23% of all RAAPs). Conclusion: High‐resolution, sequential endocardial EGM‐based mapping allows identification of RAAPs in persistent AF. In our series, focal firing was the most frequently observed pattern. [ABSTRACT FROM AUTHOR]

Conventional stylet‐driven leads with extendable helix can be implanted successfully for left bundle branch area pacing (LBBAP) with a low acute complication rate. We report two cases in which lead repositioning after a first unsuccessful attempt to LBBAP was associated with fracture of the helix rotating mechanism and failure to fully extract the pacing lead. [ABSTRACT FROM AUTHOR]

Background: There are anecdotal reports of sudden death despite a functional implantable cardioverter defibrillator (ICD). We sought to describe scenarios leading to fatal or near‐fatal outcome due to inappropriately inhibited ICD therapy in devices programmed with single‐chamber detection criteria. Methods: Programmed settings, episode lists, and intracardiac electrograms from 24 patients with a life‐threatening event (n = 12) or fatal outcome (n = 12) related to failed ventricular arrhythmia detection were used to clarify the underlying scenario. Results: Fifty episodes of failed ventricular arrhythmia detection were identified and categorized into six scenarios: (1) spontaneous ventricular tachycardia (VT) or ventricular fibrillation (VF) with a rate below the detection limits, (2) misclassification of polymorphic VT (PVT) or VF as supraventricular tachycardia (SVT), (3) misclassification of VT/VF as cluster of nonsustained VT episodes, (4) misclassification of monomorphic VT (MVT) as SVT, (5) inappropriate shock abortion, and (6) false termination detection. These scenarios occurred respectively 6, 9, 3, 9, 8, and 15 times. In 9/9 (100%) patients with PVT/VF classified as SVT, rate stability was active for rates ranging from 222 to 250 beats/min. MVT detected as SVT was due to the sudden onset criterion in 7/9 (78%) patients and twice a consequence of the rate stability criterion active for rates ranging from 200 to 250 beats/min. Conclusion: We describe six scenarios leading to failure of ventricular arrhythmia detection in a single‐chamber detection setting withholding life‐saving therapy. These scenarios are more likely to occur with high‐rate programming and long detection times, especially if combined with rate stability and sudden onset. [ABSTRACT FROM AUTHOR]

Partial Coronary Sinus Disconnection During Atrial Tachycardia. Introduction: Persistent atrial fibrillation (AF) ablation may lead to partial disconnection of the coronary sinus (CS). As a result, disparate activation sequences of the local CS versus contiguous left atrium (LA) may be observed during atrial tachycardia (AT). We aimed to evaluate the prevalence of this phenomenon and its impact on activation mapping. Methods: AT occurring after persistent AF ablation were investigated in 74 consecutive patients. Partial CS disconnection during AT was suspected when double potentials with disparate activation sequences were observed on the CS catheter. Endocardial mapping facing CS bipoles was performed to differentiate LA far-field from local CS potentials. Results: A total of 149 ATs were observed. Disparate LA-CS activations were apparent in 20 ATs after magnifying the recording scale (13%). The most common pattern (90%) was distal to proximal endocardial LA activation against proximal to distal CS activation, the latter involving the whole CS or its distal part. Perimitral macroreentry was more common when disparate LA-CS activations were observed (67% vs 29%; P = 0.002). Partial CS disconnection also resulted in 'pseudo' mitral isthmus (MI) block during LA appendage pacing in 20% of patients as local CS activation was proximal to distal despite distal to proximal activation of the contiguous LA. Conclusion: Careful analysis of CS recordings during AT following persistent AF ablation often reveals disparate patterns of activation. Recognizing when endocardial LA activation occurs in the opposite direction to the more obvious local CS signals is critical to avoid misleading interpretations during mapping of AT and evaluation of MI block. (J Cardiovasc Electrophysiol, Vol. 23, pp. 697-707, July 2012) [ABSTRACT FROM AUTHOR]

Role of CS Occlusion for Mitral Isthmus Ablation. Objective: To evaluate the safety and outcomes of mitral isthmus (MI) linear ablation with temporary spot occlusion of the coronary sinus (CS). Background: CS blood flow cools local tissue precluding transmurality and bidirectional block across MI lesion. Methods: In a randomized, controlled trial (CS-occlusion = 20, Control = 22), MI ablation was performed during continuous CS pacing to monitor the moment of block. CS was occluded at the ablation site using 1 cm spherical balloon, Swan-Ganz catheter with angiographic confirmation. Ablation was started at posterior mitral annulus and continued up to left inferior pulmonary vein (LIPV) ostium using an irrigated-tip catheter. If block was achieved, balloon was deflated and linear block confirmed. If not, additional ablation was performed epicardially (power ≤25 W). Ablation was abandoned after ∼30 minutes, if block was not achieved. Results: CS occlusion (mean duration −27 ± 9 minutes) was achieved in all cases. Complete MI block was achieved in 13/20 (65%) and 15/22 (68%) patients in the CS-occlusion and control arms, respectively, P = 0.76. Block was achieved with significantly small number (0.5 ± 0.8 vs 1.9 ± 1.1, P = 0.0008) and duration (1.2 ± 1.7 vs 4.2 ± 3.5 minutes, P = 0.009) of epicardial radiofrequency (RF) applications and significantly lower amount of epicardial energy (1.3 ± 2.4 vs 6.3 ± 5.7 kJ, P = 0.006) in the CS-occlusion versus control arm, respectively. There was no difference in total RF (22 ± 9 vs 23 ± 11 minutes, P = 0.76), procedural (36 ± 16 vs 39 ± 20 minutes, P = 0.57), and fluoroscopic (13 ± 7 vs 15 ± 10 minutes, P = 0.46) durations for MI ablation between the 2 arms. Clinically uneventful CS dissection occurred in 1 patient Conclusions: Temporary spot occlusion of CS is safe and significantly reduces the requirement of epicardial ablation to achieve MI block. It does not improve overall procedural success rate and procedural duration. Tissue cooling by CS blood flow is just one of the several challenges in MI ablation. (J Cardiovasc Electrophysiol, Vol. 23, pp. 489-496, May 2012) [ABSTRACT FROM AUTHOR]

Idiopathic left ventricular tachycardia is an infrequent form of ventricular tachycardia associated with a structurally normal heart. The prognosis is usually benign; however, sustained cases have been reported. In this report, we describe two cases of persistent idiopathic left ventricular tachycardia complicated by tachycardia-mediated cardiomyopathy. In the first case, the patient developed a right ventricular thrombus with subsequent pulmonary embolism. In the second case, the patient developed acute pulmonary edema. Both cases were cured by catheter ablation. (PACE 2010; 1-4) [ABSTRACT FROM AUTHOR]

. Background: The 'sequential ablation' strategy for persistent AF is aimed at progressive organization of AF until the rhythm converts to sinus rhythm or atrial tachycardia (AT). During ablation of an AT, apparently seamless transitions from one organized AT to another occur. The purpose of our study was to quantify the occurrence and the mechanism of this transition. Methods and Results: Twenty-nine of 90 patients undergoing ablation for persistent AF had multiple AT during the procedure and constitute the study group. Thirty-nine direct transitions from one AT to another during ablation were observed classified in four types: type I (79.4%), i.e., a direct transition of a faster to a slower tachycardia without significant intervening pause; type II (7.69%)-transition after intervening ectopy or longer pause; type III (10.26%)-A slower AT accelerated; type IV (2.56%)-alteration of activation sequence but with no change on CL. Conclusions: Transition to a second AT occurs frequently in the midst of ablation of AT in persistent AF patients. This transition occurs most commonly abruptly within the range of a single cycle length of the original AT. This is best explained by a continuation of AT that was 'present' simultaneously with the pretransition tachycardia, being 'entrained' (for a reentrant tachycardia) or 'overdriven' for an automatic focal tachycardia. The presence of multiple tachycardia mechanisms active simultaneously would be consistent with the eclectic pathophysiology of persistent AF. (J Cardiovasc Electrophysiol, Vol. 22, pp. 506-512 May 2011) [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to assess whether additional ablation in the right atrium (RA) improves termination rate in long-lasting persistent atrial fibrillation (PsAF). Background: Prolongation of atrial fibrillation (AF) cycle length (CL) measured from the left atrial appendage predicts favorable outcome during catheter ablation of PsAF. However, in some patients, despite prolongation of AF CL in the left atrium (LA) with ablation, AF persists. We hypothesized that this persistence is due to RA drivers, and that these patients may benefit from RA ablation. Methods: In all, 148 consecutive patients undergoing catheter ablation of PsAF (duration 25 ± 32 months) were studied. AF CL was monitored in both atria during stepwise ablation commencing in the LA. Ablation was performed in the RA when all LA sources in AF had been ablated and an RA-LA gradient existed. The procedural end point was AF termination. Results: Two distinct patterns of AF CL change emerged during LA ablation. In 104 patients (70%), there was parallel increase of AF CL in LA and RA culminating in AF termination (baseline: LA 153 ms [range 140 to 170 ms], RA 155 ms [range 143 to 171 ms]; after ablation: LA 181 ms [range 170 to 200 ms], RA 186 ms [range 175 to 202 ms]). In 24 patients (19%), RA AF CL did not prolong, creating a right-to-left frequency gradient (baseline: LA 142 ms [range 143 to 153 ms], RA 145 ms [range 139 to 162 ms]; after ablation: LA 177 ms [range 165 to 185 ms], RA 152 ms [range 147 to 175 ms]). These patients had a longer AF history (23 months vs. 12 months, p = 0.001), and larger RA diameter (42 mm vs. 39 mm, p = 0.005), and RA ablation terminated AF in 55%. In the remaining 20 patients, biatrial ablation failed to terminate AF. Conclusions: A divergent pattern of AF CL prolongation after LA ablation resulted in a right-to-left gradient, demonstrating that the right atrium is driving AF in ≈20% of PsAF. [Copyright &y& Elsevier]

The article describes the case of an 18-year-old male patient with a history of paroxysmal palpitations. Twelve-lead electrocardiogram (ECG) result shows alternating P-wave morphologies during a sinus rhythm, which confirmed left lateral typical accessory pathway with bidirectional conduction characteristics. Further assessment reveals previous atrial activity with PR interval, as well as possible automatic rhythm of the accessory pathway.

Objectives: This study evaluated the role of pre-procedural clinical variables to predict procedural and clinical outcomes of catheter ablation in patients with long-lasting persistent atrial fibrillation (AF). Background: Catheter ablation of persistent AF remains a challenging task. Methods: Catheter ablation was performed in 90 patients (76 men, age 57 ± 11 years) with long-lasting persistent AF. The history of AF, echocardiographic parameters, presence of structural heart disease, and surface electrocardiogram (ECG) AF cycle length (CL) were assessed before ablation and analyzed with respect to procedural termination and clinical outcome. Mean follow-up was 28 ± 4 months. Results: Persistent AF was terminated in 76 of 90 patients (84%) by ablation. The duration of continuous AF was shorter (p < 0.0001), the surface ECG AFCL was longer (p < 0.0001), and the left atrium was smaller (p < 0.01) in patients in whom AF was terminated by catheter ablation. The surface ECG AFCL was the only independent predictor of AF termination (p < 0.01). Maintenance of sinus rhythm was associated with a shorter duration of continuous AF (p < 0.0001), a longer surface ECG AFCL (p < 0.001), and a smaller left atrium (p < 0.05) compared with those with recurrent arrhythmia. In multivariate analysis, the surface ECG AFCL and the AF duration predicted clinical success of persistent AF ablation (p < 0.01 and p < 0.05, respectively). Conclusions: The surface ECG AFCL is a clinically useful pre-ablation tool for predicting patients in whom sinus rhythm can be restored by catheter ablation. The duration of continuous AF and the surface ECG AFCL are predictive of maintenance of sinus rhythm. [Copyright &y& Elsevier]

Atrial tachycardias represent the second front of atrial fibrillation (AF) ablation. They are frequently encountered during the index ablation for patients with persistent AF and are common following ablation of persistent AF, occurring in half of all patients who have had AF successfully terminated. An atrial tachycardia is rightly seen as a failure of AF ablation, as these tachycardias are poorly tolerated by patients. This article describes a simple, practical approach to diagnosis and ablation of these atrial tachycardias. [ABSTRACT FROM AUTHOR]

We report a case of a 56-year-old man with paroxysmal atrial fibrillation who underwent segmental, ostial pulmonary vein (PV) isolation while in arrhythmia. During isolation of the left superior PV (LSPV), organized electrical activity was seen within the vein, suggestive of a PV tachycardia with a cycle length of 90 ms. Simultaneously, organized electrical activity with a cycle length of 180 ms was seen in the left inferior PV (LIPV), suggestive of 2:1 conduction between the LSPV and the LIPV. Isolation of the LIPV resulted in conversion to sinus rhythm, while confirming isolation of the LSPV by the presence of ongoing PV tachycardia in this vein. This case demonstrates a direct electrical connection between the ipsilateral left PVs, leading to maintenance of atrial fibrillation. [ABSTRACT FROM AUTHOR]

Introduction: Early arrhythmia recurrences are common within the first month after atrial fibrillation (AF) ablation. The long-term consequences of these early recurrences (ER) are controversial. We investigated whether ER were predictive of late recurrences and the impact of early reablation on clinical outcome. Methods: Three hundred two consecutive patients with paroxysmal or persistent AF were studied. Arrhythmia recurrence was defined as documented episode of AF or atrial tachycardia. Of 151 patients with ER, a subset of 61 patients had reablation within the first month following the index ablation (early reablation). In the remaining 90 patients, a repeat procedure was only performed for later arrhythmia recurrences occurring beyond 1 month. Patients were followed with clinical interview and ambulatory 24 hours monitoring. Results: Patients with and without early reablation had similar baseline characteristics including echocardiographic parameters and type of AF. During a mean follow-up of 11 ± 11 months, 82 patients (91%) without early reablation experienced late clinical recurrences. In contrast, patients with early reablation had lower rate of clinical recurrences (51% vs 91%, P < 0.0001) and fewer additional procedures (36% vs 91%, P < 0.0001). However, the total number of procedures over the entire follow-up was greater in those patients with early reablation (2.5 ± 0.7 vs 2.2 ± 0.6, P = 0.02). Conclusion: An overwhelming majority of patients with recurrences within the first month after ablation have late recurrences. An early reablation reduces the incidence of further recurrences. However, the overall number of procedures is higher in the medium-term follow-up. The optimal timing for the second procedure remains to be defined. [ABSTRACT FROM AUTHOR]

Objectives: This study sought to determine the characteristics of atrial electrograms predictive of slowing or termination of atrial fibrillation (AF) during ablation of chronic AF. Background: There is growing recognition of a role for electrogram-based ablation. Methods: Forty consecutive patients (34 male, 59 ± 10 years) undergoing ablation for chronic AF persisting for a median of 12 months (range 1 to 84 months) were included. After pulmonary vein isolation and roof line ablation, electrogram-based ablation was performed in the left atrium and coronary sinus. Targeted electrograms were acquired in a 4-s window and characterized by: 1) percentage of continuous electrical activity; 2) bipolar voltage; 3) dominant frequency; 4) fractionation index; 5) mean absolute value of derivatives of electrograms; 6) local cycle length; and 7) presence of a temporal gradient of activation. Electrogram characteristics at favorable ablation regions, defined as those associated with slowing (a ≥6-ms increase in AF cycle length) or termination of AF were compared with those at unfavorable regions. Results: The AF was terminated by electrogram-based ablation in 29 patients (73%) after targeting a total of 171 regions. Ablation at 37 (22%) of these regions was followed by AF slowing, and at 29 (17%) by AF termination. The percentage of continuous electrical activity and the presence of a temporal gradient of activation were independent predictors of favorable ablation regions (p = 0.016 and p = 0.038, respectively). Other electrogram characteristics at favorable ablation regions were not significantly different from those at unfavorable ablation regions. Conclusions: Catheter ablation at sites displaying a greater percentage of continuous activity or a temporal activation gradient is associated with slowing or termination of chronic AF. [Copyright &y& Elsevier]

Objectives: This study evaluated the impact of catheter ablation of the coronary sinus (CS) region during paroxysmal and persistent atrial fibrillation (AF). Background: The CS musculature and connections have been implicated in the genesis of atrial arrhythmias. Methods: Forty-five patients undergoing catheter ablation of AF were studied. The CS was targeted if AF persisted after ablation of pulmonary veins and selected left atrial tissue. CS ablation was commenced endocardially by dragging along the inferior paramitral left atrium. Ablation was continued from within the vessel (epicardial) if CS electrograms had cycle lengths shorter than that of the left atrial appendage. RF energy was limited to 35 W endocardially and 25 W epicardially. The impact of ablation was evaluated on CS electrogram cycle length (CSCL) and activation sequence, atrial fibrillatory cycle length measured in the left atrial appendage (AFCL) and on perpetuation of AF. Results: Endocardial ablation significantly prolonged CSCL by 17 ± 5 msec and organized the CS activation sequence (from 13% of patients before to 51% after ablation); subsequent epicardial ablation further increased local CSCL by 32 ± 27 msec (P < 0.001). AFCL prolonged significantly both during endocardial and epicardial ablation (median: 152 to 167 msec P = 0.03) and was associated with AF termination in 16 (35%) patients (46% of paroxysmal and 30% of persistent AF). AFCL prolongation ≥5 msec and/or AF termination was associated with more rapid activity in the CS region originally: P ≤ 0.04. Conclusion: Catheter ablation targeting both the endocardial and epicardial aspects of the CS region significantly prolongs fibrillatory cycle length and terminates AF persisting after PV isolation in 35% of patients. [ABSTRACT FROM AUTHOR]

Inadvertent puncture of the subclavian artery is a relatively frequent and potentially disastrous complication of attempted central venous access. Due to its noncompressible location, accidental subclavian arterial cannulation may result in hemorrhage as the sheath is removed. We report a new case of successful percutaneous closure of the subclavian artery which had been inadvertently cannulated, using a closure device based on a collagen plug (Angio-Seal, St. Jude Medical). This was performed in a patient who had received maximal antiplatelet and anticoagulation therapies because of prior coronary stenting in the context of cardiogenic shock. There was no prior angiographic assessment, as arterial puncture was presumed to have been distal to the right common artery and vertebral arteries. No complications were observed in this high-risk patient, suggesting that this technique could be used once the procedure has been evaluated prospectively. [ABSTRACT FROM AUTHOR]

The article presents a case study of an asymtomatic 22-year-old woman diagnosed with accessory pathway (AP) and hypertrophic cardiomyopathy. The patient was subjected to electrophysiology study and a 12-lead electrocardiography (ECG) had been performed which demonstrates sinus rhythm with short PR interval, slurred upstroke and broad QRS duration. It is stated that fasciculoventricular pathways are classified in Mahaim type accessory pathways and are uncommon.

The article presents information concerning the left atrial appendage (LAA) activity. It informs about a female patient with a history of familial hypertrophic cardiomyopathy and paroxysmal atrial fibrillation (AF) on whom ablation was performed to see fragmented potentials at the ostium of the LAA. It is reported that the surface electrocardiogram shows a small but consistent wave resembling an epsilon wave.

The article presents a medical case of a 69-year old woman with left atrial mitral isthmus block after radiofrequency ablation. Ablation targeting areas of fragmented and rapid activation resulted in conversion of atrial fibrillation. Electrophysiologic study and catheter ablation where a decapolar electrode catheter was positioned in the coronary sinus.