Showing papers on "Catheter ablation published in 2005"

Updated worldwide survey on the methods, efficacy, and safety of catheter ablation for human atrial fibrillation

Abstract: Background— The purpose of this study was to provide an updated worldwide report on the methods, efficacy, and safety of catheter ablation of atrial fibrillation (AF). Methods and Results— A questi...

Radiofrequency Ablation vs Antiarrhythmic Drugs as First-line Treatment of Symptomatic Atrial Fibrillation: A Randomized Trial

Abstract: ContextTreatment with antiarrhythmic drugs and anticoagulation is considered first-line therapy in patients with symptomatic atrial fibrillation (AF). Pulmonary vein isolation (PVI) with radiofrequency ablation may cure AF, obviating the need for antiarrhythmic drugs and anticoagulation.ObjectiveTo determine whether PVI is feasible as first-line therapy for treating patients with symptomatic AF.Design, Setting, and ParticipantsA multicenter prospective randomized study conducted from December 31, 2001, to July 1, 2002, of 70 patients aged 18 to 75 years who experienced monthly symptomatic AF episodes for at least 3 months and had not been treated with antiarrhythmic drugs.InterventionPatients were randomized to receive either PVI using radiofrequency ablation (n=33) or antiarrhythmic drug treatment (n=37), with a 1-year follow-up.Main Outcome MeasuresRecurrence of AF, hospitalization, and quality of life assessment.ResultsTwo patients in the antiarrhythmic drug treatment group and 1 patient in the PVI group were lost to follow-up. At the end of 1-year follow-up, 22 (63%) of 35 patients who received antiarrhythmic drugs had at least 1 recurrence of symptomatic AF compared with 4 (13%) of 32 patients who received PVI (P<.001). Hospitalization during 1-year follow-up occurred in 19 (54%) of 35 patients in the antiarrhythmic drug group compared with 3 (9%) of 32 in the PVI group (P<.001). In the antiarrhythmic drug group, the mean (SD) number of AF episodes decreased from 12 (7) to 6 (4), after initiating therapy (P = .01). At 6-month follow-up, the improvement in quality of life of patients in the PVI group was significantly better than the improvement in the antiarrhythmic drug group in 5 subclasses of the Short-Form 36 health survey. There were no thromboembolic events in either group. Asymptomatic mild or moderate pulmonary vein stenosis was documented in 2 (6%) of 32 patients in the PVI group.ConclusionPulmonary vein isolation appears to be a feasible first-line approach for treating patients with symptomatic AF. Larger studies are needed to confirm its safety and efficacy.

Catheter ablation of long-lasting persistent atrial fibrillation: critical structures for termination.

Abstract: Background The relative contributions of different atrial regions to the maintenance of persistent atrial fibrillation (AF) are not known. Methods Sixty patients (53 +/- 9 years) undergoing catheter ablation of persistent AF (17 +/- 27 months) were studied. Ablation was performed in a randomized sequence at different left atrial (LA) regions and comprised isolation of the pulmonary veins (PV), isolation of other thoracic veins, and atrial tissue ablation targeting all regions with rapid or heterogeneous activation or guided by activation mapping. Finally, linear ablation at the roof and mitral isthmus was performed if sinus rhythm was not restored after addressing the above-mentioned areas. The impact of ablation was evaluated by the effect on the fibrillatory cycle length in the coronary sinus and appendages at each step. Activation mapping and entrainment maneuvers were used to define the mechanisms and locations of intermediate focal or macroreentrant atrial tachycardias. Results AF terminated in 52 patients (87%), directly to sinus rhythm in 7 or via the ablation of 1-6 intermediate atrial tachycardias (total 87) in 45 patients. This conversion was preceded by prolongation of fibrillatory cycle length by 39 +/- 9 msec, with the greatest magnitude occurring during ablation at the anterior LA, coronary sinus and PV-LA junction. Thirty-eight atrial tachycardias were focal (originating dominantly from these same sites), while 49 were macroreentrant (involving the mitral or cavotricuspid isthmus or LA roof). Patients without AF termination displayed shorter fibrillatory cycles at baseline: 130 +/- 14 vs 156 +/- 23 msec; P = 0.002. Conclusion Termination of persistent AF can be achieved in 87% of patients by catheter ablation. Ablation of the structures annexed to the left atrium-the left atrial appendage, coronary sinus, and PVs-have the greatest impact on the prolongation of AF cycle length, the conversion of AF to atrial tachycardia, and the termination of focal atrial tachycardias.

Catheter ablation of long-lasting persistent atrial fibrillation: Clinical outcome and mechanisms of subsequent arrhythmias

Abstract: Background: Catheter ablation of atrial fibrillation (AF) is challenging in patients with long-standing persistent AF. The clinical outcome and subsequent arrhythmia recurrence after using an ablation method targeting multiple left atrial sites with the aim of achieving acute AF termination has not been characterized. Methods: Sixty patients (mean age: 53 ± 9 years) with persistent AF (mean duration: 17 ± 27 months) were prospectively followed after catheter ablation. Catheter ablation targeting the following sites was performed in a random sequence: (i) electrical isolation of all pulmonary veins (PV); (ii) disconnection of other thoracic veins; (iii) atrial ablation at sites possessing complex electrical activity, activation gradients, or short cycle lengths. Finally, linear ablation of the LA roof and mitral isthmus was performed if sinus rhythm was not restored following energy delivery to the above sites. At 1, 3, 6, and 12 months after ablation, patients underwent clinical review and 24-hour ambulatory ECG monitoring to identify asymptomatic arrhythmia. Repeat mapping and catheter ablation was performed in any patient experiencing recurrent atrial tachycardia (AT). Clinical success was defined as the absence of any sustained atrial arrhythmia. Results: AF terminated during ablation in 52 patients (87%). The fluoroscopy and procedural durations were 84 ± 30 minutes and 264 ± 77 minutes, respectively. Three months after ablation, sustained ATs were documented in 24 patients (associated with AF in 2). Mapping in 23 patients showed a single AT in 7 while multiple ATs were observed in 16. Macroreentry was confirmed to be due to gaps in the ablation lines, while focal ATs originated from discrete sites or isthmuses near the left atrial appendage, coronary sinus, pulmonary veins, or fossa ovalis; these sites were similar to those at which the greatest impact was observed on the fibrillatory process during the initial ablation procedure. After repeat ablation, at 11 ± 6 months of follow-up, 57 patients (95%) were in sinus rhythm and 3 developed recurrent AF or AT. All patients in sinus rhythm demonstrated improved exercise capacity and all but 2 had evidence of atrial transport as assessed by Doppler echocardiography (mitral A wave velocity 34 ± 17 cm/sec) by 6 months. Conclusion: Catheter ablation of long-lasting persistent AF associated with acute AF termination achieves medium to long-term restoration and maintenance of sinus rhythm in 95% of patients. Arrhythmia recurrence in the majority of patients is AT.

Perception of Atrial Fibrillation Before and After Radiofrequency Catheter Ablation. Relevance of Asymptomatic Arrhythmia Recurrence

Abstract: Background— The objective of this study was to assess the incidence and impact of asymptomatic arrhythmia in patients with highly symptomatic atrial fibrillation (AF) who qualified for radiofrequency (RF) catheter ablation. Methods and Results— In this prospective study, 114 patients with at least 3 documented AF episodes together with corresponding symptoms and an ineffective trial of at least 1 antiarrhythmic drug were selected for RF ablation. With the use of CARTO, circumferential lesions around the pulmonary veins and linear lesions at the roof of the left atrium and along the left atrial isthmus were placed. A continuous, 7-day, Holter session was recorded before ablation, right after ablation, and after 3, 6, and 12 months of follow-up. During each 7-day Holter monitoring, the patients recorded quality and duration of any complaints by using a detailed symptom log. More than 70 000 hours of ECG recording were analyzed. In the 7-day Holter records before ablation, 92 of 114 patients (81%) had docume...

Freedom From Atrial Tachyarrhythmias After Catheter Ablation of Atrial Fibrillation A Randomized Comparison Between 2 Current Ablation Strategies

Abstract: Background— Data on the comparative value of the circumferential pulmonary vein and the segmental pulmonary vein ablation for interventional treatment of atrial fibrillation are limited. We hypothesized that the circumferential pulmonary vein ablation approach was superior to the segmental pulmonary vein ablation approach. Methods and Results— One hundred patients with highly symptomatic atrial fibrillation were randomly assigned to undergo either circumferential (n=50) or segmental pulmonary vein ablation (n=50). Freedom from atrial tachyarrhythmias in a 7-day Holter monitoring at 6 months was the primary end point. Secondary end points were freedom of arrhythmia-related symptoms and a composite of pericardial tamponade, thromboembolic complications, and pulmonary vein stenosis (safety end point). On the basis of the results of the 7-day Holter monitoring at 6 months, 21 patients (42%) after circumferential pulmonary vein ablation and 33 patients (66%) after segmental pulmonary vein ablation (P=0.02) wer...

Reversal of Cardiomyopathy in Patients With Repetitive Monomorphic Ventricular Ectopy Originating From the Right Ventricular Outflow Tract

Abstract: Background— Tachycardia-induced cardiomyopathy caused by ventricular tachycardia is a well-defined clinical entity. Less well appreciated is whether simple ventricular ectopy can result in cardiomyopathy. We sought to examine a potential causal relationship between repetitive monomorphic ventricular ectopy originating from the right ventricular outflow tract and cardiomyopathy and the role of ablation in reversing this process. Methods and Results— The study consisted of 27 patients (11 men; age, 47±15 years) with repetitive monomorphic ventricular ectopy, including 8 patients (30%) with depressed ventricular function (ejection fraction ≤45%). All patients underwent assessment of cardiac structure and function. The burden of ectopy was quantified through 24-hour Holter monitoring. Patients then underwent ablation guided by 3D mapping. After ablation, patients underwent repeated Holter monitoring and reassessment of cardiac function. Patients with depressed ventricular function were more likely to be older...

Clinical Presentation, Investigation, and Management of Pulmonary Vein Stenosis Complicating Ablation for Atrial Fibrillation

Abstract: Background— Although segmental or circumferential ablation is effective in eliminating pulmonary vein (PV)–mediated atrial fibrillation (AF), this procedure may be complicated by the occurrence of PV stenosis. Methods and Results— To establish the clinical presentation, diagnostic manifestations, and interventional management of PV stenosis, 23 patients with stenosis of 34 veins complicating ablation of AF were evaluated. Each patient became symptomatic 103±100 days after undergoing ablation. In 8 veins, the ablation producing the PV stenosis was a repeated procedure for continued AF. Nineteen patients presented with dyspnea on exertion, 7 with dyspnea at rest, 9 with cough, and 6 with chest pain. On multirow spiral computed tomography examination, the narrowest lumen of the affected PVs measured 3±2 mm compared with 13±3 mm at baseline (P≤0.001). The relative perfusion of affected lung segments on isotope scans was reduced to 4±3% of total perfusion compared with 22±10% in unaffected segments. At percuta...

Surgical treatment of atrial fibrillation; a systematic review.

Abstract: In this review the efficacies of the alternative sources of energy (radiofrequency-microwave and cryo ablation; group I) and the classical 'cut and sew' Cox-Maze III (group II), which claims a 97-99% sinus rhythm (SR) success rate, were evaluated in the surgical treatment of atrial fibrillation (AF). A computerized search in the PubMed and Medline database was conducted. Only original, English written, clinical manuscripts on the surgical treatment of atrial fibrillation using an alternative source of energy or the classical 'cut and sew' Cox-Maze III technique, citing the clinical outcome, including the postoperative sinus rhythm, were included. The data included in this review were the number and percentage of treated patients, gender distribution, the type of arrhythmia and surgery, postoperative morbidity, pacemaker implantation rate, 30-day mortality, survival- and sinus rhythm conversion rates. Mean values for age, left atrial diameter, preoperative duration of AF and left ventricular ejection fraction were also recorded. Forty-eight studies were included comprising 3832 patients; 2279 in group I and 1553 in group II. The mean duration of AF, left atrial diameter and LVEF were 5.4 vs. 5.5 years (p=0.90), 55.5 vs. 57.8 mm (p=0.23) and 57 vs. 58% (p= 0.63). The postoperative SR rates for group I and II were 78.3 vs. 84.9% (p=0.03). However, the "cut and sew" Cox-Maze III was conducted in younger patients (55.0 vs. 61.2 years; p=0.005), more often to treat paroxysmal (22.9 vs. 8.0%; p=0.05) and lone AF (19.3 vs. 1.6%). Alternative sources of energy were predominantly used to treat permanent AF (92.0%), almost always as a concomitant surgical procedure (98.4%) and increasingly in combination with non-mitral valve surgery (18.5%). After correction for these variations, the postoperative SR conversion rates for group I and II did not differ significantly anymore (p=0.260). Conclusions: We could not identify any significant difference in the postoperative SR conversion rates between the classical 'cut and sew' and the alternative sources of energy, which were used to treat atrial fibrillation.

Anatomic Relations Between the Esophagus and Left Atrium and Relevance for Ablation of Atrial Fibrillation

Abstract: Background— Esophageal injury is a potential complication after intraoperative or percutaneous transcatheter ablation of the posterior aspect of the left atrium. Understanding the spatial relations between the esophagus and the left atrium is essential to reduce risks. Methods and Results— We examined by gross dissection the course of the esophagus in 15 cadavers. We measured the minimal distance of the esophageal wall to the endocardium of the left atrium with histological studies in 12 specimens. To measure the transmural thickness of the atrial wall, we sectioned another 30 human heart specimens in the sagittal plane at 3 different regions of the left atrium. The esophagus follows a variable course along the posterior aspect of the left atrium; its wall was <5 mm from the endocardium in 40% of specimens. The posterior left atrial wall has a variable thickness, being thickest adjacent to the coronary sinus and thinnest more superiorly. Behind is a layer of fibrous pericardium and fibrofatty tissue of ir...

Reverse Remodeling of the Left Cardiac Chambers After Catheter Ablation After 1 Year in a Series of Patients With Isolated Atrial Fibrillation

Abstract: Background— Isolated atrial fibrillation (AF) is associated with mild enlargement of the left atrium (LA) and left ventricular (LV) diastolic dysfunction. The impact of ablation of isolated AF on left chamber size and function is unclear, and whether diastolic dysfunction is the cause or the consequence of AF remains unknown. The objective of this prospective study was to evaluate the impact of sinus rhythm restoration by catheter ablation on LV diastolic dysfunction, LA morphology, and mechanical function. Methods and Results— Forty-eight patients with isolated AF were studied by serial echocardiographic studies at baseline and at 1-, 3-, 6-, 9-, and 12-month intervals after radiofrequency ablation. LA dimensions and mechanical function and LV systolic and diastolic functions were evaluated at each time interval. Diastolic function was assessed with conventional Doppler parameters and new indexes such as tissue Doppler imaging, mitral flow propagation velocity, and combined criteria. LV diastolic dysfunc...

Electrophysiological Findings During Ablation of Persistent Atrial Fibrillation With Electroanatomic Mapping and Double Lasso Catheter Technique

Abstract: Background— Pulmonary veins (PVs) can be completely isolated with continuous circular lesions (CCLs) around the ipsilateral PVs. However, electrophysiological findings have not been described in detail during ablation of persistent atrial fibrillation (AF). Methods and Results— Forty patients with symptomatic persistent AF underwent complete isolation of the right-sided and left-sided ipsilateral PVs guided by 3D mapping and double Lasso technique during AF. Irrigated ablation was initially performed in the right-sided CCLs and subsequently in the left-sided CCLs. After complete isolation of both lateral PVs, stable sinus rhythm was achieved after AF termination in 12 patients; AF persisted and required cardioversion in 18 patients. In the remaining 10 patients, AF changed to left macroreentrant atrial tachycardia in 6 and common-type atrial flutter in 4 patients. All atrial tachycardias were successfully terminated during the procedure. Atrial tachyarrhythmias recurred in 15 of 40 patients at a median of...

Use of autonomic nervous system neurotransmitters inhibition and atrial parasympathetic fibers ablation for the treatment of atrial arrhythmias and to preserve drug effects

Abstract: Atrial arrhythmias, a major contributor to cardiovascular morbidity, are believed to be influenced by autonomic nervous system tone. The main purpose of this invention was to highlight new findings that have emerged in the study of effects of autonomic nervous system tone on atrial arrhythmias, and its interaction with class III antiarrhythmic drug effects. This invention evaluates the significance of sympathetic and parasympathetic activation by determining the effects of autonomic nervous system using a vagal and stellar ganglions stimulation, and by using autonomic nervous system neurotransmitters infusion (norepinephrine, acetylcholine). This invention evaluates the autonomic nervous system effects on the atrial effective refractory period duration and dispersion, atrial conduction velocity, atrial wavelength duration, excitable gap duration during a stable circuit (such atrial flutter circuit around an anatomical obstacle), and on the susceptibility of occurrence (initiation, maintenance and termination) of atrial re-entrant arrhythmias in canine. This invention also evaluates whether autonomic nervous system activation effects via a local neurotransimitters infusion into the right atria can alter those of class III antiarrhythmic drug, sotalol, during a sustained right atrial flutter. This invention represents an emergent need to set-up and develop a new class of anti-cholinergic drug therapy for the treatment of atrial arrhythmias and to combine this new anti-cholinergic class to antiarrhythmic drugs. Furthermore, this invention also highlights the importance of a local application of parasympathetic neurotransmitters/blockers and a catheter ablation of the area of right atrium with the highest density of parasympathetic fibers innervation. This may significantly reduce the occurrence of atrial arrhythmias and may preserve the antiarrhythmic effects of any drugs used for the treatment of atrial re-entrant arrhythmias.

Left Mitral Isthmus Ablation Associated with PV Isolation: Long‐Term Results of a Prospective Randomized Study

Abstract: Background: The deployment of an ablation line connecting the left inferior PV to the mitral annulus (mitral isthmus line [MIL]) enhances the efficacy of pulmonary vein disconnection (PVD) in preventing atrial fibrillation (AF) recurrences. Objectives: To investigate the long-term effect of the additional linear lesion in a prospective randomized study. Methods: One hundred and eighty-seven patients (37 females, mean age: 55 ± 11 years) with paroxysmal (126) or persistent (61 patients) AF, were prospectively randomized into two groups: PVD (group A, 92 patients) or PVD combined with MIL (group B, 95 patients), performed by means of an irrigated-tip ablation catheter. Results: Successful disconnection of all PVs was achieved in all patients. A bidirectional block (BB) along the left atrial isthmus was obtained in 72 of 95 (76%) patients in group B, most of whom required additional RF pulses from within the distal CS. A transient ischemic attack occurred in 1 patient of group A, and a cardiac tamponade occurred in 1 patient of group B. At 1 year, 53 ± 5% (group A) and 71 ± 5% (group B) remained arrhythmia free (P = 0.01); subgroup analysis highlights a higher improvement among patients with persistent AF (74 ± 9% vs 36 ± 9%; P < 0.01) than what was observed in paroxysmal AF (76 ± 6% vs 62 ± 6%; P < 0.05); antiarrhythmic drugs were continued in 56% and 50%, respectively, in groups A and B (P = ns). Conclusions: The addition of mitral isthmus line to the PV disconnection allows a significant improvement of sinus rhythm maintenance rate, particularly in patients with persistent AF, without the risk for major complications.

Comparing the outcomes of radiofrequency ablation and surgery in patients with a single small hepatocellular carcinoma and well-preserved hepatic function.

Abstract: Goals:To compare the efficacy of radiofrequency ablation (RFA) and surgical resection in a group of patients with a Child-Pugh score of 5 and a single HCC less than 4 cm in diameter.Background:Radiofrequency ablation (RFA) has become a popular method for treatment of hepatocellular carcinoma (HCC) a

Increased intensity of anticoagulation may reduce risk of thrombus during atrial fibrillation ablation procedures in patients with spontaneous echo contrast.

Abstract: Introducton:A 10% incidence of left atrial (LA) thrombus formation has been detected using intracardiac echocardiography (ICE) imaging monitoring during LA ablation for atrial fibrillation (AF). The aim of this study was to determine if the intensity of anticoagulation reduces LA thrombus formation during pulmonary vein isolation procedure in patients with AF and spontaneous echo contrast (SEC). Methods and Results:We studied 511 patients (age 56 ± 10 years) undergoing pulmonary vein ostial isolation/ablation using radiofrequency energy. SEC was detected in 179 of 511 patients with ICE imaging before dual transseptal catheterization. All patients were anticoagulated with heparin to achieve activated clotting time (ACT) 250–300 seconds (group I) or >300 seconds (group II) confirmed at 30-minute intervals. SEC was detected in 49/294 (16.7%) patients in group I versus 130/217 (59.9%) in group II (P < 0.0001). LA thrombus was observed in 33/294 (11.2%) patients in group I versus 6/217 (2.8%) in group II (P < 0.05). For those patients with SEC, LA thrombus was observed in 22/49 (44.9%) in group I versus 2/61 (4.6%) in group II (P < 0.0001). There were no significant differences in age, number of unsuccessful drugs, persistent AF, left ventricular ejection fraction, and LA diameter between the two groups. No clinical embolic event was observed with withdrawal of LA thrombus to the RA. Conclusion:ICE-diagnosed SEC before transseptal catheterization identifies an increased risk of LA thrombus. Increased intensity of heparin anticoagulation (ACT >300 seconds) during LA ablation for AF may prevent LA thrombus formation especially in patients with SEC.

Assessment of Temperature, Proximity, and Course of the Esophagus During Radiofrequency Ablation Within the Left Atrium

Abstract: Background— Left atrioesophageal fistula is a devastating complication of atrial fibrillation ablation. There is no standard approach for avoiding this complication, which is caused by thermal injury during ablation. The objectives of this study were to evaluate the course of the esophagus and the temperature within the esophagus during pulmonary vein antrum isolation (PVAI) and correlate these data with esophagus tissue damage. Methods and Results— Eight-one patients presenting for PVAI underwent esophagus evaluation that included temperature probe placement. Esophagus course was obtained with computed tomography, 3D imaging (NAVX), or intracardiac echocardiography. For each lesion, the power, catheter and esophagus temperature, location, and presence of microbubbles were recorded. Lesion location and esophagus course were defined with 6 predetermined left atrial anatomic segments. Endoscopy evaluated tissue changes during and after PVAI. Of 81 patients, the esophagus coursed near the right pulmonary vei...

Short- and Long-Term Success of Substrate-Based Mapping and Ablation of Ventricular Tachycardia in Arrhythmogenic Right Ventricular Dysplasia

Abstract: Background— Multiple morphologies, hemodynamic instability, or noninducibility may limit ventricular tachycardia (VT) ablation in patients with arrhythmogenic right ventricular dysplasia (ARVD). Substrate-based mapping and ablation may overcome these limitations. We report the results and success of substrate-based VT ablation in ARVD. Methods and Results— Twenty-two patients with ARVD were studied. Traditional mapping for VT was limited because of multiple/changing VT morphologies (n=14), nonsustained VT (n=10), or hemodynamic intolerance (n=5). Sinus rhythm CARTO mapping was performed to define areas of “scar” (<0.5 mV) and “abnormal” myocardium (0.5 to 1.5 mV). Ablation was performed in “abnormal” regions, targeting sites with good pace maps compared with the induced VT(s). Linear lesions were created in these areas to (1) connect the scar/abnormal region to a valve continuity or other scar or (2) encircle the scar/abnormal region. Eighteen patients had implanted cardioverter defibrillators, 15 had imp...

Incidence and predictors of pulmonary vein stenosis following catheter ablation of atrial fibrillation using the anatomic pulmonary vein ablation approach: results from paired magnetic resonance imaging.

Abstract: Pulmonary Vein Stenosis After Atrial Fibrillation Ablation. introduction: There are currently no studies systematically evaluating pulmonary vein (PV) stenosis following catheter ablation of atrial fibrillation (AF) usingthe anatomic PV ablation approach. Methods and Results: Forty-one patients with AF underwent anatomic PV ablation under the guidance of a three-dimensional electroanatomic mapping system. Gadolinium-enhanced magnetic resonance (MR) imaging was performed in all patients prior to and 8-10 weeks after ablation procedures for screening of PV stenosis. A PV stenosis was defined as a detectable (≥3 mm) narrowing in PV diameter. The severity of stenosis was categorized as mild ( 70%). A total 157 PVs were analyzed. A detectable PV narrowing was observed in 60 of 157 PVs (38%). The severity of stenosis was mild in 54 PVs (34%), moderate in five PVs (3.2%), and severe in one PV (0.6%). All mild PV stenoses displayed a concentric pattern. Moderate or severe PV stenosis was only observed in patients with an individual encircling lesion set. Multivariable analysis identified individual encircling lesion set and larger PV size as the independent predictors of detectable PV narrowing. All patients with PV stenosis were asymptomatic and none required treatment. Conclusions: The results of this study demonstrate that detectable PV narrowing occurs in 38% of PVs following anatomic PV ablation. Moderate or severe PV stenosis occurs in 3.8% of PVs. The high incidence of mild stenosis likely reflects reverse remodeling rather than pathological PV stenosis. The probability of moderate or severe PV stenosis appears to be related to creation of individual encircling rather than encircling in pairs lesion.

Ablation of idiopathic right ventricular outflow tract tachycardia: current perspectives.

Abstract: Ventricular tachycardia (VT) arising from the right ventricular outflow tract (RVOT) in the absence of overt structural heart disease is a common entity. Exclusion of occult structural disease such as arrhythmogenic right ventricular cardiomyopathy is critical as this diagnosis impacts both ablation outcomes and long-term prognosis. VT is most commonly due to triggered activity. Induction of the target arrhythmia in the laboratory is often problematic, and is frequently facilitated by catecholamine infusion. Recent data indicate that high-density three-dimensional activation mapping facilitates identification of target sites for ablation, and that the spatial resolution of pacemapping may be more limited than previously recognized. A standard 12-lead electrocardiogram is useful in providing an initial approximation of the site of origin within the outflow tract, and may contain subtle clues to potentially confounding foci on the left ventricular endocardial or epicardial surface. When sufficient arrhythmia is present to permit mapping, successful ablation can be expected in 90-95% of patients, with a recurrence risk of approximately 5%. In experienced centers, major complications are

Cerebral Diffusion-Weighted Magnetic Resonance Imaging: A Tool to Monitor the Thrombogenicity of Left Atrial Catheter Ablation

Abstract: Cerebral MRI After Left Atrial Ablation. Introduction: Cerebral embolism and stroke are feared complications of left atrial catheter ablation such as pulmonary vein (PV) ablation. In order to assess the thrombogenicity of left atrial catheter ablation, knowledge of both clinically evident as well as silent cerebral embolism is important. The aim of the current study was to examine the use of diffusion-weighted magnetic resonance imaging (DW-MRI) for detection of cerebral embolism, apparent as well as silent, caused by PV catheter ablation. Methods and Results: Twenty consecutive patients without structural heart disease undergoing lasso catheter-guided ostial PV ablation using an irrigated-tip ablation catheter were studied. Cerebral MRI including DW single-shot spin echo echoplanar, turbo fluid attenuated inversion recovery, and T2-weighted turbo spin echo sequences were performed the day after the ablation procedure. Ten patients also underwent preprocedure cerebral MRI. All ablation procedures were performed without acute complications. A mean of 3.2 ± 0.6 PVs were ablated per patient. No patient had neurological symptoms following the procedure. In 2 of 20 patients (10%), DW-MRI revealed new embolic lesions, which were located in the right periventricular white matter in one and in the left temporal lobe in the other patient. There was no statistically significant difference in age, history of hypertension, left atrial volume, and procedure duration between the 2 patients with and the 18 patients without cerebral embolism following AF ablation. Conclusion: This is the first study using highly sensitive DW-MRI of the brain to detect asymptomatic cerebral embolism after left atrial catheter ablation. Even small, clinically silent, embolic lesions can be demonstrated with this technique. DW-MRI can be used to monitor and compare the thrombogenicity of different AF ablation approaches.