Dianna Bash

Phased-array intracardiac echocardiography monitoring during pulmonary vein isolation in patients with atrial fibrillation: impact on outcome and complications.

Background—The objective of this study was to assess the impact of intracardiac echocardiography (ICE) on the long-term success and complications in patients undergoing pulmonary vein isolation (PVI) for treatment of atrial fibrillation (AF). Methods and Results—Three hundred fifteen patients underwent PVI for treatment of AF. Each patient underwent ostial isolation of all PVs using a cooled-tip ablation catheter. PVI was performed using circular mapping (CM) alone (group 1, 56 patients), CM and ICE (group 2, 107 patients), and CM and ICE with titration of radiofrequency energy based on visualization of microbubbles by ICE (group 3, 152 patients). After a mean follow-up time of 417±145 days, 19.6% (11 of 56), 16.8% (18 of 107), and 9.8% (15 of 152) of patients in groups 1, 2, and 3 experienced recurrence of AF, respectively. Moreover, whereas no group 3 patient experienced severe (>70%) PV stenosis, severe PV stenosis was documented in 3 (3.5%) of 56 patients in group 1 and in 2 (1.8%) of 107 patients in group 2 (P <0.05). No embolic events were detected in group 3 patients. Conclusions—Intracardiac echocardiography improves the outcome of cooled-tip PVI. Power adjustment guided by direct visualization of microbubble formation reduces the risk of PV stenosis and improves long-term cure.

Circular Mapping and Ablation of the Pulmonary Vein for Treatment of Atrial Fibrillation Impact of Different Catheter Technologies

OBJECTIVES We conducted this study to compare the efficacy and safety of different catheter ablation technologies and of distal versus ostial pulmonary veins (PV) isolation using the circular mapping technique. BACKGROUND Electrical isolation of the PVs in patients with atrial fibrillation (AF) remains a technical challenge. METHODS Two hundred eleven patients (163 men; mean age 53 +/- 11 years) with symptomatic AF were included in this study. In the first 21 patients (group 1), distal isolation (> or = 5 mm from the ostium) was achieved targeting veins triggering AF. In the remaining 190 patients (group 2), ostial isolation of all PVs was performed using 4-mm tip (47 patients), 8-mm tip (21 patients), or cooled-tip (122 patients) ablation catheters. RESULTS Distal isolation was able to eliminate premature atrial contractions (PACs) and AF in six of 21 patients (29%) and 10 of 34 PVs. After a mean follow-up time of 6 +/- 4 months, no patients treated with the 8-mm tip catheter experienced recurrence of AF, whereas 21% (10 of 47 patients) and 15% (18 of 122 patients) of the patients ablated with the 4-mm tip and the cooled-tip ablation catheters experienced recurrence of AF after a mean follow-up of 10 +/- 3 and 4 +/- 2 months, respectively. Significant complications including stroke, tamponade, and severe stenosis occurred in 3.5% (8/211) of patients. CONCLUSIONS Catheter technologies designed to achieve better lesion size appeared to have a positive impact on procedure time, fluoroscopy time, number of lesions, and overall efficacy. Although distal isolation can be achieved with fewer lesions, ostial isolation is required in the majority of patients to eliminate arrhythmogenic PACs and AF.

Pulmonary Vein Stenosis After Radiofrequency Ablation of Atrial Fibrillation Functional Characterization, Evolution, and Influence of the Ablation Strategy

Background—Pulmonary vein (PV) stenosis is a complication of ablation for atrial fibrillation. The impact of different ablation strategies on the incidence of PV stenosis and its functional characterization has not been described. Methods and Results—PV isolation was performed in 608 patients. An electroanatomic approach was used in 71 and circular mapping in 537 (distal isolation, 25; ostial isolation based on PV angiography, 102; guided by intracardiac echocardiography, 140; with energy delivery based on visualization of microbubbles, 270). Severe (≥70%) narrowing was detected in 21 patients (3.4%), and moderate (50% to 69%) and mild (<50%) narrowing occurred in 27 (4.4%) and 47 (7.7%), respectively. Severe stenosis occurred in 15.5%, 20%, 2.9%, 1.4%, and 0%, respectively. Development of symptoms was correlated with involvement of >1 PV with severe narrowing (P =0.01), whereas all patients with mild and moderate narrowing were asymptomatic. In the latter group, lung perfusion (V/Q) scans were normal in all but 4 patients. All patients with severe stenosis had abnormal perfusion scans. Conclusions—V/Q scans are useful to assess the functional significance of PV stenosis. Mild and moderate degrees of PV narrowing are not associated with development of symptoms and seem to have no or minimal detrimental effect on pulmonary flow. The incidence of severe PV stenosis seems to be declining with better imaging techniques to ensure ostial isolation and to guide power titration. Mild narrowing 3 months after ablation does not preclude future development of severe stenosis and should be assessed with repeat imaging studies.

First Human Experience With Pulmonary Vein Isolation Using a Through-the-Balloon Circumferential Ultrasound Ablation System for Recurrent Atrial Fibrillation

BackgroundStandard mapping and ablation of focal sources of atrial fibrillation are associated with very long procedure times and low efficacy. An anatomic approach to complete pulmonary vein isolation could overcome these limitations. Methods and ResultsFifteen patients with atrial fibrillation refractory to medication underwent circumferential isolation of the pulmonary veins by using a novel catheter, with an ultrasound transducer (8-MHz) mounted near the tip, in a saline-filled balloon. Twelve atrial foci and/or atrial fibrillation triggers were identified in 9 patients (pulmonary vein locations: left upper, 3; right upper, 6; right middle, 1; right lower, 1; and left inferior, 1). In 5 patients, lesions were placed in the absence of any mapped triggers. Irrespective of trigger mapping, circumferential isolation of both upper pulmonary veins was attempted in all patients. The lower pulmonary veins were ablated when sinus rhythm activation mapping revealed evidence of a sleeve of atrial muscle in the vein. The median number of lesions per patient required to isolate 1 pulmonary vein was 4 (range, 1 to 29). After ablation, no evidence of narrowing was seen with repeat venography or follow-up computed tomography scan. After a mean follow-up of 35±6 weeks, 5 patients had recurrence of atrial fibrillation. Three responded to drugs that were previously ineffective, and 2 remained in atrial fibrillation. ConclusionsThis novel ultrasound ablation system can successfully isolate multiple pulmonary veins. At early follow-up, this approach seems to be effective in preventing recurrent atrial fibrillation in a significant number of patients.

Ventricular tachycardias arising from the aortic sinus of valsalva: an under-recognized variant of left outflow tract ventricular tachycardia.

OBJECTIVES To describe a normal heart left bundle branch block, inferior axis ventricular tachycardia (VT), that could not be ablated from the right or left ventricular outflow tracts. BACKGROUND Whether these VTs are epicardial and can be identified by a specific electrocardiographic pattern is unclear. METHODS Twelve patients with normal heart left bundle branch block, inferior axis VT and previously failed ablation were included in this study. Together with mapping in the right and left ventricular outflow tracts, we obtained percutaneous epicardial mapping in the first five patients and performed aortic sinus of Valsalva mapping in all patients. RESULTS No adequate pace mapping was observed in the right and left ventricular outflow tracts. Earliest ventricular activation was noted in the epicardium and the aortic cusps. All patients were successfully ablated from the aortic sinuses of Valsalva (95% CI 0% to 18%). The electrocardiographic pattern associated with this VT was left bundle branch block, inferior axis and early precordial transition with Rs or R in V2 or V3. Ventricular tachycardia from the left sinus had rS pattern in lead I, and VT from the noncoronary sinus had a notched R wave in lead I. None of the patients had complications and all remained arrhythmia-free at a mean follow-up of 8 +/- 2.6 months. CONCLUSIONS Normal heart VT with left bundle branch block, inferior axis and early precordial transition can be ablated in the majority of patients from either the left or the noncoronary aortic sinus of Valsalva.

Pulmonary Vein Stenosis after Catheter Ablation of Atrial Fibrillation: Emergence of a New Clinical Syndrome

Context Because electrical signals initiating atrial fibrillation originate in the pulmonary veins, radiofrequency catheter ablation has been highly successful in curing the arrhythmia. Pulmonary vein stenosis is a recognized complication of this procedure, but past research has not established its frequency or clinical characteristics. Contribution Of 335 patients who received catheter ablation, 18 developed severe pulmonary vein stenosis. Only 44% were symptomatic. Failure to recognize the problem often led to inappropriate work-up and treatment. After pulmonary vein dilatation and stenting, 57% of patients improved. Implications Pulmonary vein stenosis following catheter ablation of atrial fibrillation is relatively common and clinically recognizable. Mechanical relief of venous obstruction can alleviate symptoms. The Editors Atrial fibrillation is one of the most common cardiac rhythm disorders and is associated with significant morbidity and mortality. Recent advances in the pathophysiologic understanding of this disorder have pointed to a focal origin that is mainly localized in the pulmonary veins and is thus amenable to ablative catheter procedures (1-6). Pulmonary vein stenosis is a recognized potential complication of radiofrequency ablation. Its incidence has been reported to range from 3% to 42%, depending on the ablative technique used and the method of assessment (6-11). Recognition of pulmonary vein stenosis is important to avoid unnecessary work-up and to allow initiation of appropriate treatment. However, reports on the constellation of signs and symptoms characterizing pulmonary vein stenosis are lacking. In this study, we describe our experience with patients who developed pulmonary vein stenosis as a complication of radiofrequency ablation of atrial fibrillation. Methods Study Sample Three hundred thirty-five patients (272 men; mean age, 54.0 years [range, 18 to 79 years]) with symptomatic, drug-refractory atrial fibrillation (mean duration [SD], 5.4 3.6 years) were referred to our laboratory for electrophysiologic study and catheter ablation. Therapy with antiarrhythmic drugs and use of oral anticoagulants were discontinued 5 half-lives and 5 days, respectively, before ablation. In all but three patients, amiodarone was withdrawn 1 month before the procedure. Informed consent was obtained from all patients before the procedure, and the institutional review board approved the collection and analysis of the data. In 71 patients, we used a three-dimensional nonfluoroscopic electroanatomic system (CARTO, Biosense Webster, Diamond Bar, California) to map and ablate arrhythmogenic pulmonary veins, as described elsewhere (3). Briefly, this system uses a low-level magnetic field to continuously record the mapping catheter location and create a catalog of electrical activity. The acquired information is then color-coded and displayed on a three-dimensional chamber geometry model of the heart chamber of interest. In 264 additional patients, we instead performed circumferential mapping and electrical isolation of all pulmonary veins, regardless of demonstration of ectopic activity. Procedure Description Patients came to the electrophysiology laboratory while fasting. Immediately before the procedure, transesophageal echocardiography was performed in all patients to exclude left atrial thrombus. A custom-made catheter (Cardiac Assist Device, Inc., Cleveland, Ohio) was placed in the coronary sinus. The proximal eight electrodes were positioned between the superior vena cava and the high crista terminalis, whereas the distal eight electrodes were placed in the coronary sinus. A transesophageal recording lead was used to record activation of the left atrial posterior wall. Mapping of left atrium and pulmonary veins was completed after the left atrium was accessed through the transseptal approach. A circular catheter (LASSO, Biosense Webster) and a steerable quadripolar catheter were placed in the pulmonary veins for mapping and ablation, respectively, through separate transseptal access points. Quadripolar 4-mmtip, 8-mmtip (Biosense Webster), and cooled-tip (Chilli, EPT, Sunnyvale, California) catheters were used for ablation. The procedure end point was the demonstration of electrical isolation of all pulmonary veins from the left atrium by evidence of entrance block. Initially, radiofrequency lesions were delivered inside the veins. For most patients, however, proximal isolation was obtained by energy delivery at the pulmonary veinleft atrium junction, which was defined by a phase-array intracardiac echocardiographic probe or by pulmonary vein angiography. The latter was performed during adenosine-induced asystole for better resolution. In patients in whom the electroanatomic system was used, only the superior pulmonary veins were targeted, unless firing from other veins was noted. The pulmonary vein profiles were reconstructed by using the electroanatomic system and by angiography. The procedure end point was pulmonary vein isolation, elimination of ectopic activity capable of initiating atrial fibrillation, or both. Follow-up Patients were given aspirin immediately after the procedure, and warfarin was restarted on the same evening. Antiarrhythmic medications were used for 6 weeks in patients who had permanent atrial fibrillation before the procedure. An arrhythmia transmitter was given to all patients before hospital discharge for detection of recurrent atrial fibrillation. Routine follow-up visits took place 3, 6, and 12 months after the procedure. Spiral computed tomography (CT) of the pulmonary veins, with three-dimensional reconstruction, was performed 3 months after ablation in all patients, regardless of the development of symptoms, to screen for pulmonary vein stenosis. Computed tomography was considered earlier if symptoms suggestive of stenosis developed; it was repeated at 6 and 12 months if any degree of pulmonary vein narrowing was observed. Pulmonary vein stenosis was judged by digital measurements of luminal diameters on adjacent segments as well as by comparison with previous films, when available. Stenosis was considered mild if luminal narrowing was less than 50%, moderate if luminal narrowing was 50% to 70%, or severe if luminal narrowing was more than 70%. Statistical Analysis We used the paired t-test to compare perfusion scan data and the Fisher exact test to evaluate the relation between the number of stenosed pulmonary veins and symptoms. StatXact software, version 3.0 (Cytel Corp., Cambridge, Massachusetts), was used for these analyses. Results Demographic characteristics of the study sample are presented in Table 1. At the 6-month follow-up visit, pulmonary vein isolation guided by the circular mapping technique had cured atrial fibrillation without use of medications in 80% of patients (212 of 264). Thirty-five patients underwent a second procedure, which resulted in an overall success rate of 92% (243 of 264 patients). This represented a significant improvement when compared with the electroanatomically guided technique, in which only 30% patients (21 of 71) were free of arrhythmia while not taking medications. Table 1. Demographic Characteristics of the Study Sample at Baseline Eighteen of 335 patients (5% [95% CI, 3% to 8%]) developed severe pulmonary vein stenosis, detected by spiral CT, a mean (SD) of 5.2 2.6 months after ablation. The mean age of these patients was 50.6 years (range, 26 to 71 years), and 78% were men. Five of these 18 patients (28%) had structural heart disease. The mean number of pulmonary veins ablated was three per patient (range, two to four per patient). Twelve patients had ablation guided by the circular mapping technique, and 6 patients had ablation guided by the CARTO system. Shortness of breath, the only respiratory symptom detected before the ablation procedure, was present in 5 patients and was attributed to atrial fibrillation. One patient had underlying pulmonary disease (asthma). Eight patients with severe pulmonary vein stenosis (44%) were asymptomatic. Among patients who had symptoms, shortness of breath was the most prevalent (8 patients [44%]), followed by cough (7 patients [39%]) and hemoptysis (5 patients [28%]). Pleuritic pain was observed in 4 patients (22%) and was usually associated with hemoptysis and cough. The presence of severe stenosis in more than one pulmonary vein was associated with a higher risk for symptoms (relative risk, 12.5 [CI, 1.2 to 391]; P = 0.04). Radiographic findings were abnormal in 9 of the 18 patients with severe stenosis (50%). The most common abnormal finding was lung consolidation (observed in 78% of patients), followed by left pleural effusions (observed in 56% of patients). Of note, in 7 of the 9 patients with radiologic abnormalities of the lungs (78%), symptoms were initially attributed to other diseases: pneumonia (4 patients), lung cancer (1 patient), and pulmonary embolism (2 patients). It is important to note that pulmonary vein stenosis was not initially considered in any of the patients who had the disorder. Misdiagnoses led to improper diagnostic and therapeutic procedures, such as prolonged antibiotic treatment (5 patients), treatment for possible asthmatic syndrome and bronchitis (3 patients), placement of a vena cava filter (1 patient), and lung resection surgery (1 patient). Table 2 summarizes the clinical and radiologic findings and pulmonary vein interventions performed. Of interest, in 5 patients who initially presented with symptomatic pulmonary vein stenosis (50%), symptoms spontaneously resolved before interventional procedures were undertaken. Table 2. Summary of Clinical and Radiologic Findings and Pulmonary Vein Interventions in 18 Patients Lung perfusion scans were obtained before and after pulmonary vein dilatation and showed a significant improvement in perfusion after the intervention. Average pulmonary flow to the affected lung increased from 15% (CI, 2% to 33%) to 23% (

Percutaneous Pericardial Instrumentation for Endo-Epicardial Mapping of Previously Failed Ablations

Background—The epicardial location of an arrhythmia could be responsible for unsuccessful endocardial catheter ablation. Methods and Results—In 48 patients referred after prior unsuccessful endocardial ablation, we considered percutaneous, subxiphoid instrumentation of the pericardial space for mapping and ablation. Thirty patients had ventricular tachycardia (VT), 6 patients had a right- and 4 had a left-sided accessory pathway (AP), 4 patients had inappropriate sinus tachycardia, and 4 patients had atrial arrhythmias. Of the 30 VTs, 24 (6 with ischemic cardiomyopathy, 3 with idiopathic cardiomyopathy, and 15 with normal hearts) appeared to originate from the epicardium. Seventeen (71%) of these 24 VTs were successfully ablated with epicardial lesions. The other 7 VTs had early epicardial sites that were inaccessible, predominantly because of interference from the left atrial appendage. Six of these were successfully ablated from the left coronary cusp. In 5 of the 10 patients with an AP, the earliest activation was recorded epicardially. Three of these were right atrial appendage–to–right ventricle APs, and epicardial ablation was successful. No significant complications were observed. Conclusions—Failure of endocardial ablation could reflect the presence of an epicardial arrhythmia substrate. Epicardial instrumentation and ablation appeared feasible and safe and provided an alternative strategy for the treatment of patients with a variety of arrhythmias. This was particularly true for VT, including patients without structural heart disease.

Empirical pulmonary vein isolation in patients with chronic atrial fibrillation using a three-dimensional nonfluoroscopic mapping system: Long-term follow-up

KANAGARATNAM, L., et al.: Empirical Pulmonary Vein Isolation in Patients with Chronic Atrial Fibrillation Using a Three‐Dimensional Nonfluoroscopic Mapping System: Long‐Term Follow‐Up. The purpose of this study was to assess the feasibility and long‐term results of empirical isolation of both superior pulmonary veins in patients with chronic AF. Although localizing and ablating the focal triggers of AF has been proven an effective approach, this strategy is time consuming, often requires multiple procedures, and carries the risk of pulmonary vein stenosis. Whether ostial electrical isolation of the superior pulmonary veins, without initial detailed mapping, is a more efficient approach is not known. The study included 71 consecutive patients who had chronic AF. Using a nonfluoroscopic electroanatomic mapping system, the left and right superior pulmonary veins were ablated circumferentially at the venoatrial junction, with the aim of achieving electrical isolation of the veins. Following ablation, if frequent atrial ectopies were present, mapping and ablation were considered. The patients were periodically followed with 48‐hour Holter and loop recorder monitoring. After the ablation of the right and left superior pulmonary veins 59 (83%) of 71 patients maintained sinus rhythm without premature atrial beats. The remaining 12 patients underwent further mapping and ablation including 5 patients who required isolation of the left inferior pulmonary veins. True electrical isolation could be achieved only in 45 (31%) of the 147 targeted veins. At the latest follow‐up (mean 29 ± 8 months), 80% of the patients with upper vein isolation remained in sinus rhythm off medications, 62% of the patients maintained sinus rhythm on previously ineffective medications, and 17% continued to be in AF. Fourteen (20%) patients developed intermittent episodes of left atrial flutter, and mapping in these patients revealed large electrically silent areas in the left atrium. Empirical isolation of pulmonary veins appeared to be an effective approach to help maintain sinus rhythm in patients with chronic AF. True electrical isolation of the pulmonary veins was associated with a higher likelihood of long‐term success. Left atrial flutter was seen in a significant number of patients at long‐term follow‐up.

Randomized Study Comparing Combined Pulmonary Vein–Left Atrial Junction Disconnection and Cavotricuspid Isthmus Ablation Versus Pulmonary Vein–Left Atrial Junction Disconnection Alone in Patients Presenting With Typical Atrial Flutter and Atrial Fibrillation

Background—Atrial flutter (AFL) and atrial fibrillation (AF) frequently coexist in the same patient. Recently it has been demonstrated that the triggers for both AF and AFL may originate in the pulmonary veins (PVs). We hypothesized that in patients with both AF and typical AFL, pulmonary vein–left atrial junction (PV-LAJ) disconnection may eliminate both arrhythmias. Methods and Results—Consecutive patients with documented symptomatic AF and typical AFL were randomly assigned to have PV-LAJ disconnection combined with cavotricuspid isthmus (CTI) ablation (group 1, n=49) or PV-LAJ disconnection alone (group 2, n=59). Within the first 8 weeks after ablation, 32 of the group 2 patients had typical AFL documented, whereas none was seen in group 1. Twenty of these 32 converted to sinus rhythm after initiating antiarrhythmic drugs (AADs). Twelve were cardioverted, and AADs were started. After 8 weeks, all AADS were stopped, and only 3 patients continued to have recurrent sustained typical AFL that was eliminated by CTI ablation. Beyond 8 weeks of follow-up, 7 patients in group 1 and 6 patients in group 2 (14% and 11%, respectively) continued to have AF. Ten of these 13 patients underwent a repeat PV-LAJ disconnection procedure and were cured. The remaining 3 remained in normal sinus rhythm while taking AADs. Conclusions—In patients with both AFL and AF, PV-LAJ disconnection alone may be sufficient to control both arrhythmias. CTI block reduced early postablation recurrence of arrhythmias, which in the majority of patients reflects a short-term clinical problem.

Varespladib and Cardiovascular Events in Patients With an Acute Coronary Syndrome The VISTA-16 Randomized Clinical Trial

IMPORTANCE Secretory phospholipase A2 (sPLA2) generates bioactive phospholipid products implicated in atherosclerosis. The sPLA2 inhibitor varespladib has favorable effects on lipid and inflammatory markers; however, its effect on cardiovascular outcomes is unknown. OBJECTIVE To determine the effects of sPLA2 inhibition with varespladib on cardiovascular outcomes. DESIGN, SETTING, AND PARTICIPANTS A double-blind, randomized, multicenter trial at 362 academic and community hospitals in Europe, Australia, New Zealand, India, and North America of 5145 patients randomized within 96 hours of presentation of an acute coronary syndrome (ACS) to either varespladib (n = 2572) or placebo (n = 2573) with enrollment between June 1, 2010, and March 7, 2012 (study termination on March 9, 2012). INTERVENTIONS Participants were randomized to receive varespladib (500 mg) or placebo daily for 16 weeks, in addition to atorvastatin and other established therapies. MAIN OUTCOMES AND MEASURES The primary efficacy measure was a composite of cardiovascular mortality, nonfatal myocardial infarction (MI), nonfatal stroke, or unstable angina with evidence of ischemia requiring hospitalization at 16 weeks. Six-month survival status was also evaluated. RESULTS At a prespecified interim analysis, including 212 primary end point events, the independent data and safety monitoring board recommended termination of the trial for futility and possible harm. The primary end point occurred in 136 patients (6.1%) treated with varespladib compared with 109 patients (5.1%) treated with placebo (hazard ratio [HR], 1.25; 95% CI, 0.97-1.61; log-rank P = .08). Varespladib was associated with a greater risk of MI (78 [3.4%] vs 47 [2.2%]; HR, 1.66; 95% CI, 1.16-2.39; log-rank P = .005). The composite secondary end point of cardiovascular mortality, MI, and stroke was observed in 107 patients (4.6%) in the varespladib group and 79 patients (3.8%) in the placebo group (HR, 1.36; 95% CI, 1.02-1.82; P = .04). CONCLUSIONS AND RELEVANCE In patients with recent ACS, varespladib did not reduce the risk of recurrent cardiovascular events and significantly increased the risk of MI. The sPLA2 inhibition with varespladib may be harmful and is not a useful strategy to reduce adverse cardiovascular outcomes after ACS. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01130246.