Safety of catheter ablation for atrial fibrillation in patients with mechanical prosthetic valves.

BACKGROUND: Catheter ablation (CA) for atrial fibrillation (AF) is increasingly utilized in recent years, with promising results. We aimed to investigate the nationwide trends in utilization and procedural complications of CA for AF in patients with mechanical prosthetic valves (MPVs). METHODS AND RESULTS: We drew data from the US National Inpatient Sample (NIS) database to identify cases of AF ablations in patients with MPVs, between 2003 and 2015. Sociodemographic and clinical data were collected, and incidence of procedural complications, mortality, and length of stay were analyzed. We compared the outcomes to a propensity-matched cohort of patients without MPVs. The study included a weighted total of 1898 CA for AF cases in patients with MPVs. The median age of the study population was 67 (61-75) years and 53% were males. Despite the increasing age and significant uptrend in the prevalence of individual comorbidities and Deyo-Charlson Comorbidity Index (CCI) over the years, the risk of peri-procedural complications and mortality in the study group did not change between the early (2003-2008) and late (2009-2015) study years. The peri-procedural complication rate (8.4% vs. 10.4%, p = .33) and in-hospital mortality (0.2% vs. 0.2%, p = .9) did not differ significantly between patients with MPVs and 1901 matched patients without MPVs. Length of stay was higher among patients with prior MPVs compared to the controls (4.0 ± 0.2 vs. 3.3 ± 0.2 days, p = .011). CONCLUSION: This nationwide analysis shows that AF ablation in patients with mechanical valve prothesis bares a similar risk of periprocedural complications and mortality as in patients without prosthetic valves.

The Impact of Obesity on Sudden Cardiac Death Risk.

PURPOSE OF REVIEW: We aimed to describe the epidemiology of sudden cardiac death (SCD) in the obese, elaborating on the potential pathophysiological mechanisms linking obesity, SCD, and the outcomes in SCD survivors, as well as looking into the intriguing "obesity paradox" in these patients. RECENT FINDINGS: Several studies show increased mortality in patients with BMI > 30 kg/m2 admitted to the hospital following SCD. At the same time, other studies have implied that the "obesity paradox," described in various cardiovascular conditions, applies to patients admitted after SCD, showing lower mortality in the obese compared to normal weight and underweight patients. We found a significant body of evidence to support that while obesity increases the risk for SCD, the outcomes of obese patients post SCD are better. These findings should not be interpreted as supporting weight gain, as it is always better to prevent the "disaster" from happening than to improve your chances of surviving it. Obesity is shown to be significantly associated with increased risk for SCD; however, there is a growing body of evidence, supporting the "obesity paradox" in the survival of SCD victims. Prospectively, well-designed studies are needed to confirm these findings.

Ventricular arrhythmia ablation in the presence of mechanical valve utilization and complications of catheter ablation for ventricular arrhythmia in patients with mechanical prosthetic valves.

BACKGROUND: Catheter ablation (CA) for ventricular arrhythmias (VAs) is increasingly utilized in recent years. We aimed to investigate the nationwide trends in utilization and procedural complications of CA for VAs in patients with mechanical valve (MV) prosthesis. METHODS: We drew data from the US National Inpatient Sample database to identify cases of VA ablations, including premature ventricular contraction and ventricular tachycardia, in patients with MVs, between 2003 and 2015. Sociodemographic and clinical data were collected and the incidence of catheter ablation complications, mortality, and length of stay were analyzed. We compared the outcomes to a propensity-matched cohort of patients without prior valve surgery. RESULTS: The study population included a weighted total of 647 CA cases in patients with prior MVs. The annual number of ablations almost doubled, from 34 ablations on average during the "early years" (2003-2008) to 64 on average during the "late years" (2009-2015) of the study (p = .001). Length of stay at the hospital did not differ significantly between patients with MVs and 649 matched patients without prior MVs (5.4 ± 0.4, 4.7 ± 0.3 days, respectively, p = .12). The data revealed a trend toward a higher incidence of complications (12.6% vs. 7.5% respectively, p = .14) and mortality (3.7% vs. 0.7%, respectively, p = .087) among patients with MVs compared to the matched control group, not reaching statistical significance. CONCLUSION: The data show increased utilization of VA ablations in patients with MVs and a trend toward a higher incidence of in-hospital mortality and complications compared to the propensity-matched control group without MVs.

How a concentration-effect analysis of data from the eliglustat thorough electrocardiographic study was used to support dosing recommendations.

Eliglustat is a first-line oral treatment for adults with Gaucher disease type 1 who have cytochrome P450 (CYP) 2D6 extensive, intermediate, or poor metabolizer phenotypes. Per International Conference on Harmonisation (ICH) E14 guidance, a Phase 1 thorough electrocardiographic (ECG) study was done during drug development to assess eliglustat's effects on cardiac repolarization by measuring ECG intervals in healthy adult subjects. Using data from the thorough ECG study, we performed pharmacokinetic/pharmacodynamic-ECG modeling to establish the relationship between eliglustat concentrations and their effects on ECG intervals. We then used that concentration-response relationship to predict the effects of eliglustat on each ECG interval for each CYP2D6 metabolizer phenotype (the main determinant of eliglustat exposure) and in different drug-drug interaction scenarios. These predictions, together with other exposure-related factors, contributed to the CYP2D6 phenotype-based dosing recommendations for eliglustat, including dose adjustments and contraindications when co-administered with drugs metabolized by the CYP2D6 and CYP3A pathways.

Economic impact of contact force sensing in catheter ablation for atrial fibrillation.

AIMS: The TactiCath Contact Force Ablation Catheter Study for Atrial Fibrillation (TOCCASTAR) clinical trial compared clinical outcomes using a contact force (CF) sensing ablation catheter (TactiCath) with a catheter that lacked CF measurement. This analysis links recorded events in the TOCCASTAR study and a large claims database, IBM MarketScan®, to determine the economic impact of using CF sensing during atrial fibrillation (AF) ablation. METHODS AND RESULTS: Clinical events including repeat ablation, use of antiarrhythmic drugs, hospitalization, perforation, pericarditis, pneumothorax, pulmonary edema, pulmonary vein stenosis, tamponade, and vascular access complications were adjudicated in the year after ablation. CF was characterized as optimal if greater than or equal to 90% lesion was performed with greater than or equal to 10 g of CF. A probabilistic 1:1 linkage was created for subjects in MarketScan® with the same events in the year after ablation, and the cost was evaluated over 10 000 iterations. Of the 279 subjects in TOCCASTAR, 145 were ablated using CF (57% with optimal CF), and 134 were ablated without CF. In the MarketScan® cohort, 9811 subjects who underwent AF ablation were used to determine events and costs. For subjects ablated with optimal CF, total cost was $19 271 ± 3705 in the year after ablation. For ablation lacking CF measurement, cost was $22 673 ± 3079 (difference of $3402, P < .001). In 73% of simulations, optimal CF was associated with lower cost in the year after ablation. CONCLUSION: Compared to ablation without CF, there was a decrease in healthcare cost of $3402 per subject in the first year after the procedure when optimal CF was used.

Isolated very low QRS voltage predicts response to tilt-table testing in patients with neurally mediated syncope.

BACKGROUND: A number of patients with neurally mediated syncope (NMS) have isolated QRS complexes of very low voltage (≤0.3 mV) in the frontal plane leads on the 12-lead electrocardiogram (ECG). HYPOTHESIS: The aim of this study was to assess the importance of QRS voltage in predicting response to tilt-table testing (TTT) in patients with suspected NMS. METHODS: We included 216 patients (age: 49 ± 20 years, 103 men) with suspected NMS who had either a positive or negative response to TTT (n = 91 TTT+, and n = 125 TTT-). The QRS voltage was measured in mV on 12-lead ECGs performed within 3 days of the TTT. The lowest QRS voltage (QRSmin), as well as the voltage in each of the 12 leads was also determined. RESULTS: Very low voltage (QRSmin  ≤ 0.3 mV) in the frontal leads was significantly more prevalent in the TTT+ group than in the TTT- group (74 vs 22%, respectively; P  < .001). Patients in the TTT+ group had significantly lower QRSmin when compared to patients in the TTT- group. QRSmin predicted a positive tilt-table test in a multivariate model that also included patient gender, height, history of presyncope, QRS duration, and left ventricular end-diastolic diameter indexed to height. ROC analysis showed that QRSmin of ≥0.3 mV discriminated between TTT+ and TTT- patients with a sensitivity of 78% and specificity of 68%. CONCLUSION: Isolated very low QRS voltage in the frontal leads predicts a positive response to TTT in patients with suspected NMS.

Safety and efficacy of delivering high-power short-duration radiofrequency ablation lesions utilizing a novel temperature sensing technology.

Aims: Delivery of high-power short-duration radiofrequency (RF) ablation lesions is not commonly used, in part because conventional thermocouple (TC) technology underestimates tissue temperature, increasing the risk of steam pop, and thrombus formation. We aimed to test whether utilization of an ablation catheter equipped with a highly accurate novel TC technology could facilitate safe and effective delivery of high-power RF lesions. Methods and results: Adult male Yorkshire swine were used for the study. High-power short-duration ablations (10-s total; 90 W for 4 s followed by 50 W for 6 s) were delivered using an irrigated force sensing catheter, equipped with six miniature TC sensors embedded in the tip electrode shell. Power modulation was automatically performed when the temperature reached 65°C. Ablation parameters were recorded and histopathological analysis was performed to assess lesion formation. One hundred and fourteen RF applications, delivered using the study ablation protocol in the ventricles of eight swine [53 in the right ventricle (RV), 61 in the left ventricle (LV)], were analysed. Average power delivered was 55.4 ± 5.3 W and none of the ablations resulted in a steam pop. Fourteen out of the 114 (12.3%) lesions were transmural. The mean lesion depth was 3.9 ± 1.1 mm for the 100 non-transmural lesions. Similar ablation parameters resulted in bigger impedance drop (11.6 Ω vs. 9.1 Ω, P = 0.009) and deeper lesions in the LV compared with the RV (4.3 ± 1.2 mm vs. 3.3 ± 0.8 mm, P < 0.001). Conclusion: Delivery of high-power short-duration RF energy applications, facilitated by a novel ablation catheter system equipped with advanced TC technology, is feasible, safe, and results in the formation of effective ablation lesions.

Utilization and in-hospital complications of cardiac resynchronization therapy: trends in the United States from 2003 to 2013.

Aims: Cardiac resynchronization therapy (CRT) device implantation has been shown to reduce morbidity and mortality in selected patients with heart failure. We sought to investigate the utilization and in-hospital complications of cardiac resynchronization therapy defibrillator (CRT-D) and pacemaker (CRT-P) implantations in the United States from 2003 to 2013. Methods and results: Patients receiving CRT-D or CRT-P were identified in the National Inpatient Sample database (NIS), using the International Classification of Diseases-Ninth Revision-Clinical Modification procedure codes. Annual implantation rates, patient demographics, co-morbidities, in-hospital complications, and length of stay were analysed. From 2003 to 2013, an estimated total of 439 010 (95% CI: 406 723-471 296) inpatient CRT implantations were performed in the U.S. The median age of patients was 72 and 71% were male. Overall, 6.1% had at least one complication. During the study period, comorbidity index and overall complication rate increased (P = 0.002 and P = 0.01, respectively). Mortality and length of stay showed no significant trend. Predictors of complications included: age 65 and older, female sex (OR: 1.19; 95% CI: 1.12-1.27), Deyo-Charlson Comorbidity Index, and elective admission (OR: 0.61; 95% CI: 0.57-0.66). Conclusion: From 2003 to 2013, the severity of comorbid conditions increased and a rising trend was observed in the rate of periprocedural complications among patients undergoing CRT in the United States. In-hospital mortality and length of stay showed no uniform trend.

Impact of treatment crossovers on clinical outcomes in the rate and rhythm control strategies for atrial fibrillation: Insights from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial.

We investigated the rates and reasons for crossover to alternative treatment strategies and its impact on mortality in patients who were enrolled in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial. Over a mean follow-up period of 3.5 years, 842 patients underwent crossover to the alternative treatment arms in AFFIRM. The rate of crossover from rhythm to rate control (594/2,033, 29.2%) was more frequent than the rate of crossover from rate to rhythm control (248/2,027, 12.2%, P < 0.0001). The leading reasons for crossover from rhythm to rate control were failure to achieve or maintain sinus rhythm (272/594, 45.8%) and intolerable adverse effects (122/594, 20.5%). In comparison, the major reasons for crossover from rate to rhythm control were failure to control atrial fibrillation symptoms (159/248, 64.1%) and intolerable adverse effects (9/248, 3.6%). This difference in crossover pattern was statistically significant (P < 0.0001). There was a significantly decreased risk of all-cause mortality (adjusted HR: 0.61, 95% CI: 0.48-0.78, P < 0.0001) and cardiac mortality (adjusted hazard ratio [HR]: 0.61, 95% confidence interval [CI]: 0.43-0.88, P = 0.008) in the subgroup of patients who crossed over from rhythm to rate control as compared to those who continued in rhythm control. There was a nonsignificant trend toward decreased all-cause (adjusted HR: 0.76, 95% CI: 0.53-1.10, P = 0.14) and cardiac mortality (adjusted HR: 0.70, 95% CI: 0.42-1.18, P = 0.18) in patients who crossed over from rate to rhythm control as compared to those who continued rate control.

Impact of Periprocedural Colchicine on Postprocedural Management in Patients Undergoing a Left Atrial Appendage Ligation Using LARIAT.

INTRODUCTION: Left atrial appendage (LAA) can be effectively and safely excluded using a novel percutaneous LARIAT ligation system. However, due to pericardial catheter manipulation and LAA ligation and subsequent necrosis, postprocedural course is complicated by pericarditis. We intended to evaluate the preprocedural use of colchicine on the incidence of postprocedural pericardial complications. METHODS AND RESULTS: In this multicenter observational study, we included all consecutive patients who underwent LARIAT procedure at the participating centers. Many patients received periprocedural colchicine at the discretion of the physician. We compared the postprocedural outcomes of patients who received prophylactic periprocedural colchicine (colchicine group) with those who did not receive colchicine (standard group). A total of 344 consecutive patients, 243 in the "colchicine group" and 101 in the "standard group," were included. The mean age, median CHADS2VASc score, and HASBLED scores were 70 ± 11 years, 3 ± 1.7, and 3 ± 1.1, respectively. There were no significant differences in major baseline characteristics between the two groups. Severe pericarditis was significantly lower in the "colchicine group" compared to the "standard group" (10 [4%] vs. 16 [16%] P<0.0001). The colchicine group, compared to the standard group, had lesser pericardial drain output (186 ± 84 mL vs. 351 ± 83, P<0.001), shorter pericardial drain duration (16 ± 4 vs. 23 ± 19 hours, P<0.04), and similar incidence of delayed pericardial effusion (4 [1.6%] to 3 [3%], P = 0.42) when compared to the standard group. CONCLUSION: Use of colchicine periprocedurally was associated with significant reduction in postprocedural pericarditis and associated complications.

Long-Term Outcome of Patients With Idiopathic Ventricular Fibrillation: A Meta-Analysis.

BACKGROUND: The long-term outcome of the patients with idiopathic ventricular fibrillation (IVF) is not well known. METHODS AND RESULTS: 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]). CONCLUSIONS: 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.

Pulmonary Vein Isolation Using the Visually Guided Laser Balloon: Results of the U.S. Feasibility Study.

INTRODUCTION: 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. METHODS: 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 minutes beyond the 90-day blanking, the inability to isolate 1 superior and 2 total PVs, occurrence of left atrial flutter or atrial tachycardia, or left atrial ablation/surgery during follow-up. RESULTS: 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 minutes, 205.2 ± 61.7 minutes, and 253.5 ± 71.3 minutes, 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. CONCLUSIONS: 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.

Pulmonary vein isolation for atrial fibrillation in the postpneumonectomy population: a feasibility, safety, and outcomes study.

BACKGROUND: Pulmonary vein isolation (PVI) of the remnant pulmonary vein (PV) stumps in pneumonectomy patients has not been well characterized. METHODS: 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. RESULTS: 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 1-year follow-up, 80% were free of AF, off of antiarrhythmic medications. CONCLUSION: 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.

Incidence and Predictors of Pacemaker Implantation in Patients Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND: 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. OBJECTIVES: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Association between atrial fibrillation and silent cerebral infarctions: a systematic review and meta-analysis.

BACKGROUND: 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. PURPOSE: To estimate the association between AF and SCIs and the prevalence of SCIs in stroke-free patients with AF. DATA SOURCES: Searches of MEDLINE, PsycINFO, Cochrane Library, CINAHL, and EMBASE from inception to 8 May 2014 without language restrictions and manual screening of article references. STUDY SELECTION: Observational studies involving adults with AF and no clinical history of stroke or prosthetic valves who reported SCIs. DATA EXTRACTION: Study characteristics and study quality were assessed in duplicate. DATA SYNTHESIS: Eleven studies including 5317 patients with mean ages from 50.0 to 83.6 years reported on the association between AF and SCIs. Autopsy studies were heterogeneous and low-quality; therefore, they were excluded from the meta-analysis of the risk estimates. When computed tomography (CT) and magnetic resonance imaging (MRI) studies were combined, AF was associated with SCIs in patients with no history of symptomatic stroke (odds ratio, 2.62 [95% CI, 1.81 to 3.80]; I(2) = 32.12%; P for heterogeneity = 0.118). This association was independent of AF type (paroxysmal vs. persistent). The results were not altered significantly when the analysis was restricted to studies that met at least 70% of the maximum possible quality score (odds ratio, 3.06 [CI, 2.24 to 4.19]). Seventeen studies reported the prevalence of SCIs. The overall prevalence of SCI lesions on MRI and CT among patients with AF was 40% and 22%, respectively. LIMITATION: Most studies were cross-sectional, and autopsy studies were heterogeneous and not sufficiently sensitive to detect small lesions. CONCLUSION: Atrial fibrillation is associated with more than a 2-fold increase in the odds for SCI. PRIMARY FUNDING SOURCE: Deane Institute for Integrative Research in Atrial Fibrillation and Stroke, Massachusetts General Hospital.

Pilot study of the effect of lipophilic vs. hydrophilic beta-adrenergic blockers being taken at time of intracardiac defibrillator discharge on subsequent PTSD symptoms.

A pathophysiological model of posttraumatic stress disorder (PTSD) posits that an overly strong stress response at the time of the traumatic event leads to overconsolidation of the event's memory in part through a central ß-adrenergic mechanism. We hypothesized that the presence of a ß-blocker in the patient's brain at the time of the traumatic event would reduce the PTSD outcome by blocking this effect. The unpredictable, uncontrollable discharge of an implantable intracardiac defibrillator (ICD) is experienced by most patients as highly stressful, and it has previously been shown to be capable of causing PTSD symptoms. The present pilot study evaluated a convenience sample of 18 male cardiac patients who had been taking either a lipophilic ß-blocker (which penetrates the blood-brain barrier) or a hydrophilic ß-blocker (which does not) at the time of a discharge of their ICD. The self- report PTSD Checklist-Specific Version quantified 17 PTSD symptoms pertaining to the ICD discharge during the month preceding the evaluation. There was a statistical trend for patients who had been taking a lipophilic ß-blocker at the time of the ICD discharge to have (35%) less severe PTSD symptoms than patients who had been taking a hydrophilic ß-blocker (one-tailed p=0.07, g=0.64). Further, prospective, randomized, controlled studies are suggested.

Incidence and predictors of atrial fibrillation and its impact on long-term survival in patients with supraventricular arrhythmias.

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), and AV nodal reentrant tachycardia (AVNRT). We hypothesized that SVA may 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 in males (35 vs. 18%). Atrial fibrillation was present in 19.6% of patients before the ablation and developed in 9.07% after ablation. Atrial fibrillation commonly occurred in patients with 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.

Cognitive impairment associated with atrial fibrillation: a meta-analysis.

BACKGROUND: Atrial fibrillation (AF) has been linked with an increased risk for cognitive impairment and dementia. PURPOSE: To complete a meta-analysis of studies examining the association between AF and cognitive impairment. DATA SOURCES: Search of MEDLINE, PsycINFO, Cochrane Library, CINAHL, and EMBASE databases and hand search of article references. STUDY SELECTION: Prospective and nonprospective studies reporting adjusted risk estimates for the association between AF and cognitive impairment. DATA EXTRACTION: Two abstracters independently extracted data on study characteristics, risk estimates, methods of AF and outcome ascertainment, and methodological quality. DATA SYNTHESIS: Twenty-one studies were included in the meta-analysis. Atrial fibrillation was significantly associated with a higher risk for cognitive impairment in patients with first-ever or recurrent stroke (relative risk [RR], 2.70 [95% CI, 1.82 to 4.00]) and in a broader population including patients with or without a history of stroke (RR, 1.40 [CI, 1.19 to 1.64]). The association in the latter group remained significant independent proof of clinical stroke history (RR, 1.34 [CI, 1.13 to 1.58]). However, there was significant heterogeneity among studies of the broader population (I2 = 69.4%). Limiting the analysis to prospective studies yielded similar results (RR, 1.36 [CI, 1.12 to 1.65]). Restricting the analysis to studies of dementia eliminated the significant heterogeneity (P = 0.137) but did not alter the pooled estimate substantially (RR, 1.38 [CI, 1.22 to 1.56]). LIMITATIONS: There is an inherent bias because of confounding variables in observational studies. There was significant heterogeneity among included studies. CONCLUSION: Evidence suggests that AF is associated with a higher risk for cognitive impairment and dementia, with or without a history of clinical stroke. Further studies are required to elucidate the association between AF and subtypes of dementia as well as the cause of cognitive impairment.

Impact of catheter ablation on P-wave parameters on 12-lead electrocardiogram in patients with atrial fibrillation.

BACKGROUND: Catheter ablation has emerged as a widely used treatment modality for atrial fibrillation (AF). P-wave abnormalities have been described in the patients with AF, and catheter ablation may potentially further impact P-wave parameters due to ablation of atrial tissue. METHODS: We reviewed data on P-wave parameters (P-wave duration, amplitude and P-wave duration and amplitude product) in leads V1 and aVF and changes in the P-terminal force (Ptf; product of duration and amplitude of terminal part of P-wave) in lead V1 from 12-lead electrocardiograms obtained prior to and after CA of a total of 46 (28 paroxysmal and 18 persistent) AF patients. RESULTS: The median age of patients in our study was 63 (range: 30-77) years. We noticed a significant reduction in the P-wave duration (from 87.39±28.62ms at baseline to 72.09±24.59ms; p=0.0072) and the product of P-wave duration and amplitude in lead V1 (12.16±5.54mVms at baseline to 8.30±5.78mVms, p=0.0015) after CA. There was also a significant decrease in P-wave duration (from 92.57±19.67ms at baseline to 76.48±16.32ms after CA, p=0.0001) and P-wave duration and amplitude product in lead aVF (12.61±4.05mVms at baseline to 9.77±3.86mVms after CA, p=0.0001). CA also led to a significant decrease in Ptf (from 4.56±1.88 at baseline to 2.85±1.42mVms, p<0.0001). CONCLUSION: Radiofrequency catheter ablation of AF leads to modification of P-wave parameters with substantial diminution in both the amplitude and duration of the P-wave in leads V1 and aVF. This likely represents reduction in electrically active atrial tissue after ablation, and may serve as a marker for the extent of ablated atrial tissue.