[Show abstract][Hide abstract] ABSTRACT: Introduction:
Phrenic nerve (PN) injury is one of the major complications of pulmonary vein isolation (PVI). Pace mapping for PN capture is routinely used to identify areas with high-risk for injury along the anterior border of the right PVs. Our aim was to evaluate the feasibility of using preprocedural imaging to identify areas where no PN capture is possible along the anterior border of the right pulmonary veins (PVs), thus avoiding the need for pace mapping during PVI.
Methods and results:
It was hypothesized that PN capture along the anterior border of the right PVs does not occur in the area where the right and left atria overlap. 3D segmentation of both atria was performed on pre-procedural magnetic resonance and computed tomography angiograms in 40 patients before undergoing PVI. The area of overlap between the right and left atria was delineated. Image registration was performed during the procedure. Using pacing, regions with and without PN capture were marked along the anterior border of the right PVs. 361 points were tested for PN stimulation (9±4 points/patient). PN capture occurred in 97 out of the 189 points (51%) in the area with no overlap between the right and left atria. No PN capture occurred in the area of overlap (172 points, p<0.001).
Delineation of the area of overlap between the right and left atria derived from preprocedural imaging reliably identifies regions where PN pace capture does not occur. Testing for PN stimulation before ablation may not be necessary in these regions.
Journal of Cardiovascular Electrophysiology 07/2015; DOI:10.1111/jce.12758 · 2.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The long-term outcome of the patients with idiopathic ventricular fibrillation (IVF) is not well known.
Relevant studies published through May 21, 2014 were searched and identified in the MEDLINE, PsycINFO, Cochrane Library, CINAHL, and EMBASE databases and a hand search of article references was also performed. Random-effect models were used for pooling proportions of mortality and recurrent events. Twenty-three studies were included with a total of 639 patients (449 males) with a mean age ranging from 33 to 51 years. Eighty percent of patients had received ICD implantation. Over an average of 5.3 years follow-up, 167 patients (31%) experienced a recurrence of ventricular arrhythmic events (proportion, 0.29 [95% CI 0.21-0.38]). Moreover, 17 patients (3.1%) died among all studies (proportion, 0.01 [95% CI 0.00-0.04]). No association was found between the induction of sustained ventricular tachycardia or ventricular fibrillation at baseline electrophysiological study and risk of recurrent ventricular arrhythmias (risk difference: 0.12 [95% CI, -0.08-0.32]).
In patients with IVF, this meta-analysis revealed an estimated recurrent event rate of 31% and a pooled mortality rate of 3.1% during an average of 5 years follow-up. The results of baseline electrophysiological studies are not predictive of future ventricular arrhythmias. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
Journal of Cardiovascular Electrophysiology 06/2015; DOI:10.1111/jce.12737 · 2.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Visually-guided laser balloon (VGLB) ablation is unique in that the operator delivers ablative energy under direct visual guidance. In this multicenter study, we sought to determine the feasibility, efficacy, and safety of performing pulmonary vein isolation (PVI) using this VGLB.
Patients with symptomatic, drug-refractory paroxysmal atrial fibrillation (AF) underwent PVI using the VGLB with the majority of operators conducting their first-ever clinical VGLB cases. The primary effectiveness endpoint was defined as freedom from treatment failure that included: occurrence of symptomatic AF episodes ≥1 min beyond the 90-day blanking, the inability to isolate one superior and two total PVs, occurrence of left atrial flutter or atrial tachycardia, or left atrial ablation/surgery during follow-up.
A total of 86 patients (mean age 56±10 years, 67% male) were treated with the VGLB at 10 US centers. Mean fluoroscopy, ablation, and procedure times were 39.8±24.3 min, 205.2±61.7 min, and 253.5±71.3 min, respectively. Acute PVI was achieved in 314/323 (97.2%) of targeted PVs. Of 84 patients completing follow-up, the primary effectiveness endpoint was achieved in 50 (60%) patients. Freedom from symptomatic or asymptomatic AF was 61%. The primary adverse event rate was 16.3% (8.1% pericarditis, phrenic nerve injury 5.8%, and cardiac tamponade 3.5%). There were no cerebrovascular events, atrioesophageal fistulas, or significant PV stenosis.
This multicenter study of operators in the early stage of the learning curve demonstrates that PVI can be achieved with the VGLB with a reasonable safety profile and an efficacy similar to radiofrequency ablation. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
Journal of Cardiovascular Electrophysiology 06/2015; DOI:10.1111/jce.12727 · 2.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Obstructive sleep apnea (OSA) is increasingly recognized as an important risk factor for arrhythmogenesis. Epidemiological and clinical studies have suggested a strong association between OSA and atrial fibrillation (AF). With the increasing global epidemic of obesity, the incidence of OSA is also expected to rise. Various mechanisms mediated through adverse electrical and structural changes have been proposed to explain the increased risk of AF in patients with OSA. Multiple studies have also observed a greater risk of AF recurrence after cardioversion and catheter ablation (CA) in the patients with untreated OSA. The epidemiological and pathophysiological associations between OSA and AF have significant implications on the treatment outcomes of rhythm-control strategies for AF. Adequate screening and optimal management of OSA are of key importance to help improve the clinical outcomes following cardioversion and CA. In this review, we sought to describe the role of various mechanisms by which OSA mediates the pathogenesis of AF and contributes to adverse outcomes following CA.
Critical Pathways in Cardiology 06/2015; 14(2):81-85. DOI:10.1097/HPC.0000000000000044
[Show abstract][Hide abstract] ABSTRACT: Transcatheter aortic valve replacement (TAVR) has emerged as an alternative treatment for patients with symptomatic aortic stenosis who are at high risk for surgical aortic valve replacement. The development of conduction abnormalities is a major complication in the postprocedural period of TAVR. The objective of this study was to investigate the development of postprocedural conduction abnormalities and the requirement of permanent pacemaker (PPM) implantation in patients undergoing TAVR. Data from 137 consecutive patients who underwent TAVR (Edwards SAPIEN valve, Edwards Lifesciences, Irvine, CA, USA) between June 2008 and October 2012 were reviewed. Patients with prior history of PPM (n = 27) were excluded. The role of various predictors for pacemaker implantation after TAVR, including the valve index (calculated as [valve size/left ventricular outflow tract diameter] × 100) was investigated. A total of 31/110 (28.2%) patients required implantation of a PPM after TAVR. The median time to implantation of a PPM was 5 days after the procedure. The development of postprocedural complete heart block was the most common indication for implantation of a PPM (16/31; 51.6%). On multivariate analysis, the presence of preexisting right bundle branch block (RBBB) was found to be a strong predictor of PPM implantation after TAVR (adjusted odds ratio: 4.87; 95% confidence interval: 1.29–18.46, P = 0.020). Using the receiver operated curve analysis, a cut-off value of valve index of 128 was found to be a strong predictor for PPM implantation with a sensitivity of 73% and specificity of 61% (c statistic = 0.68). This study identified the presence of prior RBBB and a valve index of 128 as important risk factors for PPM implantation after TAVR. A larger implanted valve size relative to left ventricular outflow tract diameter leads to a greater compression of the intrinsic conduction system, increasing the need for pacemaker placement.
[Show abstract][Hide abstract] ABSTRACT: Established classes of high-performance electronics have driven advances in interventional biomedicine. However, the large size, planar geometry and stiff mechanical properties of standard conventional electronics employed in medical devices give rise to important integration challenges with soft biological tissue. Stretchable and flexible biointegrated electronics could improve treatment procedures across a broad range of applications, including cardiac, neural and endovascular therapies. Here we present novel mechanics, materials and integration strategies for this new class of bioelectronics onboard minimally invasive catheter based systems. Co-located arrays of sensors and actuators affixed to cardiac and angioplasty balloon catheters capture new sensory information during ablation procedures, offering physicians the ability to adjust placement and treatment intra-procedurally. New circuit topologies, enabled by stretchable electronics, also overcome long standing challenges associated with transmitting vast amounts of data through narrow catheter lumens, thus allowing for a large number of sensors to be multiplexed for mapping electrophysiological activity with high spatiotemporal resolution and with a minimal number of routing wires. We present representative examples that highlight the clinical significance of soft bio-integrated electronics, along with the mechanics and processes that enable this technology.
Proceedings of the IEEE 04/2015; 103(4):682-689. DOI:10.1109/JPROC.2015.2401596 · 4.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Radiation exposure in the electrophysiology lab is a major occupational hazard to the electrophysiologists. A novel catheter localization system (Mediguide Technology, St. Jude Medical Inc., St. Paul, MN, USA) allows the integration of electroanatomical mapping and X-ray imaging, and has been shown to be effective in reducing radiation exposure during several electrophysiological procedures. We intended to evaluate the feasibility of this novel catheter tracking system to guide transseptal (TS) access.
The feasibility of performing TS puncture with MediGuide was assessed in a prospective observational study in 16 patients undergoing radiofrequency ablation (RFA) for atrial fibrillation (AF). These patients were compared to 16 matched patients undergoing similar procedures during the same time frame using conventional approach. There were no differences in mean age, gender distribution, and body mass index between the two groups. Total duration of fluoroscopic exposure during TS puncture was compared between the two groups.
All patients underwent successful TS puncture. Fluoroscopy time (FT) for double TS puncture using the MediGuide system was significantly lower than the control group (0.48 ± 0.17 min vs. 5.9 ± 0.65 min; p < 0.0001). No major complications occurred during the procedures in either group.
TS puncture can be successfully performed using MediGuide, and results in significant reduction in radiation exposure. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Recent research and publication of various landmark trials have led to the approval and subsequent use of novel oral anticoagulants (NOACs) in clinical practice. The use of these newer agents for anticoagulation offers several benefits such as greater specificity, relatively rapid onset and offset of action and a predictable pharmacological profile as compared to warfarin. With the increasing use of these agents, several key issues ranging from appropriate selection to management of complications and considerations for concurrent procedures (cardioversion and catheter ablation) have also emerged. The timing of interruption of anticoagulants prior to catheter ablation and re-initiation after the procedure to minimize the peri-procedural thromboembolism risk without increasing the bleeding risk is of key relevance in electrophysiology practice. The use of NOACs in patients undergoing catheter ablation and cardioversion also requires special considerations based on the pharmacological properties of the individual agent and the presence of comorbidities such as renal and or hepatic impairment. In this review we aim to discuss the practical considerations with the use of NOACs in the setting of cardioversion and catheter ablation based on the currently available data.
[Show abstract][Hide abstract] ABSTRACT: Pulmonary vein isolation (PVI) of the remnant pulmonary vein (PV) stumps in pneumonectomy patients has not been well characterized.
This is a multicenter observational study of patients with a remnant PV stump after pneumonectomy. Consecutive patients with a history of pneumonectomy and who had undergone RF ablation for drug refractory AF were identified from the AF database at the participating institutions.
There were 15 patients in whom pneumonectomy was performed, for resection of tumors in 10, infection in 4 and bullae in 1 patient and who underwent RF ablation for AF. The mean age was 63 ± 7 years. The stumps were from the right lower PV in 5, left upper PV in 5, left lower PV in 3 and right upper PV in 2 patients. All the PV stumps were electrically active with PV potentials and 9 (60%) of them had triggered activity. PVI was performed in 14 and focal isolation in 1 patient. At one-year follow-up, 80% were free of AF, off of antiarrhythmic medications.
PV stumps in AF patients with previous pneumonectomy are electrically active and are frequently the sites of active firing. Isolation of these PV stumps can be accomplished safely and effectively using catheter ablation with no practical concern for PV stenosis or compromising PV stump integrity. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Atrial fibrillation (AF) is a common cause of stroke. Silent cerebral infarctions (SCIs) are known to occur in the presence and absence of AF, but the association between these disorders has not been well-defined.
Annals of internal medicine 11/2014; 161(9):650-8. DOI:10.7326/M14-0538 · 17.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Atrial fibrillation (AF) is the most common cardiac arrhythmia, contributing to increased morbidity and reduced survival through its associations with stroke and heart failure. AF contributes to a four- to fivefold increase in the risk of stroke in the general population and is responsible for 10-15 % of all ischemic strokes. Diagnosis and treatment of AF require considerable health care resources. Current therapies to restore sinus rhythm in AF are suboptimal and are limited either by their pro-arrhythmic effects or by their procedure-related complications. These limitations have necessitated identification of newer therapeutic targets to expand the treatment options. There has been a considerable amount of research interest in investigating the mechanisms of initiation and propagation of AF. Despite extensive research focused on the pathogenesis of AF, a thorough understanding of various pathways mediating initiation and propagation of AF still remains limited. Research efforts focused on the identification of these pathways and molecular mediators have generated a great degree of interest for developing more targeted therapies. This review discusses the potential therapeutic targets and the results from experimental and clinical research investigating these targets.
American Journal of Cardiovascular Drugs 08/2014; 14(6). DOI:10.1007/s40256-014-0085-0 · 2.42 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND Cardiac resynchronization therapy (CRT) nonresponders have poor outcomes. The significance of progressive ventricular dysfunction among nonresponders remains unclear. OBJECTIVE We sought to define predictors of and clinical outcomes associated with progressive ventricular dysfunction despite CRT. METHODS We conducted an analysis of 328 patients undergoing CRT with defibrillator for standard indications. On the basis of 6-month echocardiograms, we classified patients as responders (those with a >= 5% increase in ejection fraction) and progressors (those with a >= 5% decrease in ejection fraction), and all others were defined as nonprogressors. Coprimary end points were 3-year (1) heart failure, left ventricular assist device (LVAD), transplantation, or death and (2) ventricular tachycardia (VT) or ventricular fibrillation (VF). RESULTS MuLtivariable predictors of progressive ventricular dysfunction were aldosterone antagonist use (hazard ratio [HR] 0.23; P = .008), prior valve surgery (HR 3.3; P = .005), and QRS duration (HR 0.98; P = .02). More favorable changes in ventricular function were associated with Lower incidences of heart failure, LVAD, transplantation, or death (70% vs 54% vs 330/e; P < .0001) and VT or VF (66% vs 38% vs 28%; P = .001) for progressors, nonprogressors, and responders, respectively. After multivariable adjustment, progressors remained at increased risk of heart failure, LVAD, transplantation, or death (HR 2.14; P = .0029) and VT or VF (HR 2.03; P = .046) as compared with nonprogressors. Responders were at decreased risk of heart failure, LVAD, transplantation, or death (HR 0.44; P < .0001) and VT or VF (0.51; P = .015) as compared with nonprogressors. CONCLUSION Patients with progressive deterioration in ventricular function despite CRT represent a high-risk group of nonresponders at increased risk of worsened clinical outcomes.
Heart rhythm: the official journal of the Heart Rhythm Society 08/2014; 11(11). DOI:10.1016/j.hrthm.2014.08.005 · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aims To determine the incidence and predictors of atrial fibrillation (AF) and its impact on survival in patients with other forms of supraventricular arrhythmias (SVAs) including atrial flutter (AFL), atrial tachycardia (AT), atrioventricular reentrant (AVRT), andAV nodal reentrant tachycardia (AVNRT). We hypothesized that SVAmay increase risk of AF and concomitant AF may influence long-term survival. Methods and results All patients who underwent catheter ablation for SVA from 2000 to 2010 were included in this study. The patients were identified retrospectively and the vital status determined prospectively. Observed survival in the study cohort was compared with survival rates in the age-and sex-matched general population. The study group included 1573 patients (mean age 50.5 +/- 18 years, 47% female) with AVNRT (38.5%), AFL (29.6%), AVRT (22.6%) and AT (9.3%). The patients were followed for a mean of 35 months (median 23 months). Atrial fibrillation was documented in 424 patients (27%) with a higher incidence inmales (35 vs. 18%). Atrial fibrillationwas present in 19.6% of patients before the ablation and developed in 9.07% after ablation. Atrial fibrillation commonly occurred in patientswith AFL (57.5%), AT (27.4%), AVRT (13.5%), and AVNRT (9.7%). Older age, prolonged PR interval, dilated left atrium, low left ventricular ejection fraction and presence of AFL were independent predictors for concomitant AF. Long-term survival was worse in the presence of AF. Conclusion The incidence of AF is high in patients with other forms of SVA. The most common association is between AFL and AF. Long-term survival is decreased in those who have concomitant AF, although AF did not emerge as an independent predictor of mortality when adjusted for other covariates.
[Show abstract][Hide abstract] ABSTRACT: Although atrial fibrillation (AF) symptom severity is used to guide clinical care, a simple, standardized assessment tool is not available for routine clinical use. We sought to develop and validate a patient-generated score and classification scheme for AF-related symptom severity and burden. Atrial Fibrillation Symptom and Burden, a simple 2-part questionnaire, was designed to assess (1) AF symptom severity using 8 questions to determine how symptoms affect daily life and (2) AF burden using 6 questions to measure AF frequency, duration, and health-care utilization. The resulting score was used to classify patients into 4 classes of symptom and burden severity. Patients were asked to complete the questionnaire, a survey evaluating the questionnaire, and an Short Form-12v2 generic health-related quality-of-life form. Validation of the questionnaire included assessments of its reliability and construct and known groups validity. The strength of interrater agreement between patient-generated and blinded provider-generated classifications of AF symptom severity was also assessed. The survey had good internal consistency (Cronbach α >0.82) and reproducibility (intraclass correlation coefficient = 0.93). There was a good linear correlation with health-related quality-of-life aggregates measured by Pearson correlation coefficient (r = 0.62 and 0.42 vs physical component summary and mental component summary, respectively). Compared with physical and mental component summary scores, the patient-generated symptom severity classification scheme showed robust discrimination between mild and moderate severity (p <0.0001 and p = 0.0009) and between moderate and severe groups (p = 0.0001 and p = 0.012). In conclusion, this simple patient-generated AF classification scheme is robust, internally consistent, reproducible, and highly correlated with standardized quality-of-life measures.
The American Journal of Cardiology 05/2014; 114(2). DOI:10.1016/j.amjcard.2014.04.032 · 3.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate the association between selective serotonin reuptake inhibitors (SSRIs) and corrected QT interval (QTc) prolongation via meta-analysis of prospective studies.
The Journal of Clinical Psychiatry 05/2014; 75(5):e441-e449. DOI:10.4088/JCP.13r08672 · 5.50 Impact Factor