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Introduction: Electrical isolation of pulmonary veins (PVI) is a cornerstone for atrial fibrillation (AF) ablation. The overall effect of AF ablation, and especially lesions beyond PVI, on left atrial (LA) function is currently poorly understood. Our aim was to determine if LA function is different in patients after extensive LA ablation compared to PVI only. We performed non‐inferiority analysis of LA function after PVI with additional nonpulmonary vein ablation lesions in LA (PVI+) and PVI alone. Methods: We studied 68 patients consecutive patients who underwent AF ablation and who had complete transthoracic echocardiogram (TTE) within 12 months before AF ablation and 1−12 months after the procedure. Patients were stratified into two groups: PVI only and PVI+. Primary outcome was change in LA reservoir strain (LASr). Noninferiority margin was defined at 6%. Results: The PVI only group had a higher proportion of patients with paroxysmal AF (70% vs. 30%). The PVI+ group was observed to have a slightly higher increase in LASr compared to PVI alone (5.0% vs. 4.3%, p <.01 for noninferiority). LASr noninferiority was confirmed when adjusted for age, sex, coronary artery disease, hyperlipidemia, and AF type, rhythm at preprocedure TTE in a multivariable linear regression model, 90% CI (−5.46 to 2.04), p <.01. Conclusion: LA functional improvement evaluated by LASr was noninferior after PVI with additional LA ablation lesions compared to PVI alone. These findings were confirmed when adjusted for confounding clinical variables, suggesting that more extensive ablation does not negatively affect LA function. [ABSTRACT FROM AUTHOR]

Introduction: Esophageal injury is rare but potentially a devastating complication of atrial fibrillation (AF) ablation. The goal here was to provide insight into the short‐term natural history of esophageal thermal injury (ETI) after radiofrequency catheter ablation (RFCA) for AFby esophagogastroduodenoscopy (EGD). Methods: We screened patients who underwent RFCA for AF and EGD based on esophageal late gadolinium enhancement (LGE) in postablation magnetic resonance imaging. Patients with ETI diagnosed with EGD were included. We defined severity of ETI according to Kansas City classification: type 1: erythema; type 2: ulcers (2a: superficial; 2b deep); type 3 perforation (3a: perforation; 3b: perforation with atrioesophageal fistula [AEF]). Repeated EGD was performed within 1−14 days after the last EGD if recommended and possible until any certain healing signs (visible reduction in size without deepening of ETI or complete resolution) were observed. Results: ETI was observed in 62 of 378 patients who underwent EGD after RFCA. Out of these 62 patients with ETI, 21% (13) were type 1, 50% (31) were type 2a and 29% (18) were type 2b at the initial EGD. All esophageal lesions, but one type 2b lesion that developed into an AEF, showed signs of healing in repeated EGD studies within 14 days after the procedure. The one type 2b lesion developing into an AEF showed an increase in size and ulcer deepening in repeat EGD 8 days after the procedure. Conclusion: We found that all ETI which did not progress to AEF presented healing signs within 14 days after the procedure and that worsening ETI might be an early signal for developing esophageal perforation. [ABSTRACT FROM AUTHOR]

Introduction: Catheter ablation (CA) for long‐standing persistent atrial fibrillation (LS‐AF) remains challenging. We aimed to explore whether sinus rhythm (SR) restoration and left atrium (LA) function after pretreatment with antiarrhythmic drugs (AAD's) and electrical cardioversion (ECV) predict procedural outcomes. Methods and Results: We included 100 consecutive patients with LS‐AF who were treated with AAD/ECV for at least 3 months before CA. The echocardiographic LA strain during reservoir phase (LASr) was assessed after pretreatment as a marker of LA fibrosis. The recurrence was recorded for ≥1 year after the last procedure. During a 34 ± 16‐month follow‐up period, the single and multiple procedures and pharmaceutically assisted success rates were 40% and 71%, respectively. Patients with preprocedural SR restoration and higher LASr showed a significantly higher recurrence‐free probability after the last CA (logrank P =.001 and P <.001, respectively). Failure of preprocedural SR restoration and LASr ≤8.6% were independently associated with recurrence after the last CA (hazard ratio [HR]: 3.13, 95% confidence interval [CI]: 1.42‐6.91, P =.005; HR: 3.89, 95% CI: 1.65‐9.17, P =.002, respectively). These parameters added incrementally to the predictive value of AF duration and LA dilatation (P =.03 and P =.002, respectively) and improved the recurrence‐risk stratification (net reclassification improvement = 0.39; 95% CI = 0.13‐0.65; P =.003). Conclusion: In patients with LS‐AF, the inability to restore SR and lower LASr after AAD/ECV treatment independently and incrementally predicts the recurrence after CA. These findings might be useful for determining LS‐AF ablation candidates. [ABSTRACT FROM AUTHOR]

Background: Class 1C antiarrhythmic drugs (AADs) are effective first‐line agents for atrial fibrillation (AF) treatment. However, these agents commonly are avoided in patients with known coronary artery disease (CAD), due to known increased risk in the postmyocardial infarction population. Whether 1C AADs are safe in patients with CAD but without clinical ischemia or infarct is unknown. Reduced coronary flow capacity (CFC) on positron emission tomography (PET) reliably identifies myocardial regions supplied by vessels with CAD causing flow limitation. Objective: To assess whether treatment with 1C AADs increases mortality in patients without known CAD but with CFC indicating significantly reduced coronary blood flow. Methods: In this pilot study, we compared patients with AF and left ventricular ejection fraction ≥50% who were treated with 1C AADs to age‐matched AF patients without 1C AAD treatment. No patient had clinically evident CAD (ie, reversible perfusion defect, known ≥70% epicardial lesion, percutaneous coronary intervention, coronary artery bypass grafting, or myocardial infarction). All patients had PET‐based quantification of stress myocardial blood flow and CFC. Death was assessed by clinical follow‐up and social security death index search. Results: A total of 78 patients with 1C AAD exposure were matched to 78 controls. Over a mean follow‐up of 2.0 years, the groups had similar survival (P =.54). Among patients with CFC indicating the presence of occult CAD (ie, reduced CFC involving ≥50% of myocardium), 1C‐treated patients had survival similar to (P =.44) those not treated with 1C agents. Conclusions: In a limited population of AF patients with preserved left ventricle function and PET‐CFC indicating occult CAD, treatment with 1C AADs appears not to increase mortality. A larger study would be required to confidently assess the safety of these drugs in this context. [ABSTRACT FROM AUTHOR]

Ultrasound Guided Vascular Access for Electrophysiologic Procedures Introduction Vascular access related complications are the most common complications from catheter based EP procedures and have been reported to occur in 1-13% of cases. We prospectively assessed vascular complications in a large series of consecutive patients undergoing catheter based electrophysiologic (EP) procedures with ultrasound (US) guided vascular access versus conventional access. Methods and Results Consecutive patients undergoing catheter ablation procedures at VCU medical center were included. US guided access was obtained in all cases starting June 2015 (US group) while modified Seldinger technique without US guidance (non-US group) was used in cases prior to this date. All vascular complications were recorded for a 30-day period after the procedure. A total of 689 patients underwent 720 procedures. Ablations for ventricular tachyarrhythmias (ventricular tachycardia: VT, premature ventricular contractions: PVCs) accounted for 89 (12%) cases; atrial fibrillation (AF) ablations accounted for 328 procedures (46%) and other catheter based procedures accounted for 42% of cases. A significantly higher incidence of complications was noted in the non-US group compared with the US group (19 [5.3%] vs. 4 [1.1%], respectively, P = 0.002). Major complications were also higher among the non-US group (9 [2.5%] vs. 2 [0.6%], P = 0.03). Increasing age (P = 0.04) and non-US guided vascular access (P = 0.002) were associated with a higher risk of vascular access complications. Conclusion In a large series of patients undergoing catheter based EP procedures for cardiac arrhythmias, US guided vascular access was associated with a significantly decreased 30-day risk of vascular complications. [ABSTRACT FROM AUTHOR]

Predict the Impact of PVC on Myocardial Function Introduction Reversible premature ventricular complexes-induced cardiomyopathy (PVC-CMP) is a well-described, multi-factorial entity. Single predictors, such as PVC burden or QRS duration, may not apply equally to all patients in contemporary unselected populations including patients with structural heart disease (SHD) or with particular origin such as epicardial (EPI) PVC. We sought to evaluate clinical criteria associated with PVC-CMP notably focusing on the EPI origin impact and ECG recognition and the value of a new composite predictor of PVC-CMP, the PVC-CMP-Index. Methods and Results We studied 107 consecutive patients (69 men; mean age = 56 ± 16 years) with frequent PVC (23.1 ± 11.5%) referred for PVC ablation. Thirty-six patients (33.6%) had an underlying SHD and 25 patients (23.4%) an EPI PVC origin. After a mean follow-up of 22.7 ± 15.3 months, 72.9% achieved a long-term successful ablation and 54.2% had PVC-CMP. PVC-CMP prevalence was significantly higher in patients with an EPI compared to endocardial PVC focus (84.0% vs. 45.1%, respectively, P < 0.001). EPI PVC origin (OR = 68.7 IC95% [3.5-1363], P = 0.005), as well as SHD (OR = 12.3 IC95% [1.6-92.6], P = 0.015), was independent predictor of PVC-CMP. While PVC burden (AUC = 0.78) or PVC-QRS width (AUC = 0.68) independently predicted PVC-CMP, the PVC-CMP-Index (values ≥39) defined as: PVC burden (0-1) × PVC-QRS width (milliseconds) × a constant C (1.28 for SHD or 2 for ECG suggesting EPI origin based on our ECG 3-step algorithm), highly correlated with PVC-CMP (AUC = 0.91, sensitivity = 93%, specificity = 80%). Conclusion We developed a new index, which incorporates PVC burden, QRS width, and presence of SHD or suspected EPI origin that best predicted PVC-CMP. [ABSTRACT FROM AUTHOR]

CRT-P versus CRT-D Outcomes Background Cardiac resynchronization therapy (CRT) is commonly used to manage heart failure, yet published guidelines do not distinguish between recommendations for pacemakers (CRT-P) and defibrillators (CRT-D) despite significant differences in size, longevity, and cost between these devices. The purpose of this study is to compare the clinical characteristics and outcomes between elderly recipients of CRT-P and CRT-D. Methods and Results Data from 512 patients (405 CRT-D, 107 CRT-P) aged ≥75 years with LV ejection fraction ≤35% and QRS duration >120 milliseconds were retrospectively analyzed for baseline characteristics and followed to the primary outcome of all-cause mortality. Cox proportional hazards models were used to adjust for possible confounders. Results were further validated through propensity matching cohorts. Compared to CRT-D recipients, CRT-P patients were older (83 years vs. 81 years, P < 0.001) and had more comorbid conditions (Charlson index = 5 [3-6] vs. 4 [3-5], P = 0.007). During 40.8 months of follow-up, there were 280 deaths. Compared to CRT-D patients, CRT-P recipients had higher unadjusted mortality (HR 1.54, 95% CI 1.15-2.08, P = 0.004). However, this difference lost significance after adjusting for baseline differences between the groups (HR 1.18, 95% CI 0.78-1.77, P = 0.435). Conclusion Higher all-cause mortality in older CRT-P versus CRT-D patients is largely explained by baseline clinical and demographic differences between the two groups, which are likely the drivers of device selection in real-world clinical practice, where the published guidelines remain ambiguous. There is a need for randomized studies to determine optimal CRT device selection. [ABSTRACT FROM AUTHOR]

Ventricular Tachycardia and Atrioventricular Block Introduction In pediatric patients with pacemakers implanted for atrioventricular block (AVB), nonsustained ventricular tachycardia (NSVT) detected during routine surveillance is a finding of unknown significance. We sought to describe the incidence of NSVT and determine if there was an association between NSVT and adverse outcomes in these patients. Methods and Results This is a single-center retrospective study of 136 patients (1971-2013) with pacemakers implanted for advanced and complete AVB. Exclusion criteria: structural heart disease, diagnoses of myocarditis, cardiomyopathy or channelopathy preceding AVB diagnosis, and sustained or polymorphic ventricular tachycardia (VT) as the first occurring arrhythmia after pacemaker implant. During median follow-up of 11.6 years (IQR 4.3 years, 17 years), 14 (10%) patients had NSVT. There were 6 (4.4%) deaths. Overall, Kaplan-Meier 20-year survival from time of implant was 93%. By univariate analysis, earlier mortality was associated with NSVT (P = 0.010), sustained left ventricular (LV) dysfunction (P = 0.004), maternal autoantibodies (P = 0.017), and acquired AVB (P = 0.049). By multivariate analysis, earlier mortality was associated with NSVT (HR: 5.39 [95% CI: 1.02-28.41]; P = 0.047) and sustained LV dysfunction (HR: 10.24 [95% CI: 1.83-57.32]; P = 0.008). Conclusions In children with pacemakers implanted for AVB, NSVT is not uncommon and may be associated with increased mortality. Persistent LV dysfunction may also be a potential factor associated with death. Closer follow-up should be considered in patients with these findings. Large, multicenter studies should be considered to confirm these findings and identify risk stratification methods for this unique patient population. [ABSTRACT FROM AUTHOR]

Focal But Not Diffuse Fibrosis Burden Predicts CRT Remodeling Response Introduction Many heart failure patients with dyssynchrony do not reverse remodel (RR) in response to cardiac resynchronization therapy (CRT). The presence of focal and diffuse interstitial myocardial fibrosis may explain this high nonresponse rate. T1 mapping is a new cardiac magnetic resonance imaging (CMR) technique that overcomes the limitations of conventional contrast CMR and provides reliable quantitative assessment of diffuse myocardial fibrosis. The study tested the hypothesis that focal and diffuse fibrosis quantification would correlate with a lack of left ventricular (LV) RR to CRT. Methods and Results In a prospective study of 48 consecutive patients (27 ischemic cardiomyopathy, 21 dilated cardiomyopathy) LV scar burdens were quantified (scar core and gray zone using late gadolinium enhancement LGE CMR; interstitial fibrosis using T1 mapping) before CRT implant. LV RR was defined by a ≥ 15% reduction in LV end-systolic volume 6 months postimplant. Twenty-seven (56%) patients were responders with RR. Association between scar quantification and LV RR was assessed using the Poisson regression model. Univariate analysis showed that QRS duration/morphology, scar core, and gray zone volumes expressed as % of LV mass and extracellular volume index (ECV) (a measure of interstitial fibrosis from T1 mapping) to be significant predictors of LV RR. Multivariable-adjusted analyses demonstrated scar core quantification (≥13.7% LV mass) to be the only independent predictor of LV RR (prevalence ratio 0.40, P = 0.038). Conclusions Focal scar burden detected by LGE CMR is associated with a poor response to CRT. Diffuse interstitial fibrosis assessment by T1 mapping, however, is not independently predictive of CRT response. [ABSTRACT FROM AUTHOR]

Impact of Age After Atrial Fibrillation Catheter Ablation Background Catheter ablation of atrial fibrillation (AF) is an established therapeutic rhythm approach in symptomatic patients. Many studies have shown that age has little to no impact on outcomes during the first year after ablation. However, AF is a disease of aging and age-based substrate for arrhythmia is likely to progress. To this regard, we examined patients with 5-year outcome data following an index AF ablation procedure to define the impact of age on long-term outcomes. Methods A total of 923 patients that underwent their index AF ablation and had 5 years of follow-up were studied. Patients were followed up for atrial flutter/AF recurrence, heart failure, stroke, death, and cardiac function. Patients were separated and compared in 5 age-based groups (<50, 51-60, 61-70, 71-80, >80). Results The average age of the population was 66 ± 11 years and 59% were male. The AF was paroxysmal in 55%, persistent in 27%, and longstanding persistent in 18%. Older patients were more likely female and had higher rates of cardiovascular diseases. For every 10-year increase in age there was a higher multivariate-adjusted risk of atrial flutter/AF recurrence (HR: 1.13, P = 0.01), death (HR:1.91, P < 0.0001), and major adverse cardiac events (HR: 1.09, P = 0.07). Although atrial flutter/AF recurrence rates by age were similar at 1 year, at 5 years, younger patients had significantly lower rates of recurrences. Conclusion Age significantly impacts outcomes after AF ablation when analyzed with long-term follow-up. These data highlight the progressive nature of AF and the need to consider interventions early. [ABSTRACT FROM AUTHOR]

Visually Guided PV Isolation 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. [ABSTRACT FROM AUTHOR]

Multiple Bursts for Fast Ventricular Tachycardia Introduction An empirical sequence of burst antitachycardia pacing (ATP) is effective in terminating fast ventricular tachycardias (FVT) in patients with implantable cardioverter-defibrillators (ICDs). We aimed to determine whether multiple ATP bursts for termination of FVT results in shock reduction compared to a single ATP burst. Methods and Results We analyzed data from the Umbrella trial, a multicenter prospective observational study of ICD patients followed by the CareLink Monitoring System. We compared the safety and effectiveness of a single ATP burst (Group 1) with a strategy of successive ATP sequences (Group 2) for termination of FVT episodes (cycle lengths 250-320 milliseconds) before shock therapy. Over a mean follow-up of 35 months, a total of 650 FVT episodes were detected in 154 patients (mean cycle length: 299 ± 18 milliseconds). Effectiveness of the first burst ATP in Group 1 was 73% and shocks were required in 27% of episodes. Effectiveness of the first burst ATP in Group 2 was 77%, and this increased to 91% with the third or successive ATP bursts. Shocks were required in 9% of episodes in group 2, representing a 67% reduction in the need of high-energy shocks. Median duration of FVT episodes and mortality in both groups were similar. Multivariate analysis indicated that programming multiple ATP bursts (OR 3.4, 95%CI 1.7-6.8, P = 0.001) was an independent predictor of ATP effectiveness. Conclusion This study provides first evidence that a strategy of multiple burst ATP sequences for termination of FVT episodes leads to a clinically meaningful reduction in the need for shocks. [ABSTRACT FROM AUTHOR]

Cardiac Autoantibodies and AF Recurrence Introduction Recent evidence has suggested that autoantibodies may play an important role in the development of atrial fibrillation (AF). The predictive value of preprocedural autoantibodies against beta-1 adrenergic receptor (anti-β1-R) and M2-muscarinic acetylcholine receptor (anti-M2-R) for AF recurrence following cryoballoon-based pulmonary vein isolation (PVI) is still unclear. We aimed to determine the predictive value of preprocedural anti-β1-R and anti-M2-R levels for AF recurrence. Methods Eighty patients (mean age 54.25 ± 7.70 years; 40% female) with paroxysmal AF and preserved left ventricular function who underwent cryoballoon-based PVI were included in the study. Preprocedural anti-M2-R and anti-β1-R levels were measured with ELISA. Results At 1-year follow-up after ablation, late AF recurrence was observed in 17 (21.25%) patients. In the Cox regression model, including number of antiarrhythmic drugs, early AF recurrence, anti-β1-R levels >159.88 ng/mL, anti-M2-R levels >277.65 ng/mL, AF duration, and left atrial volume index, only anti-β1-R levels >159.88 ng/mL (HR: 4.281, P = 0.039) and anti-M2-R levels >277.65 ng/mL (HR: 4.313, P = 0.030) were found to be independent predictors of late AF recurrence. Anti-β1-R level >159.88 ng/mL was shown to predict late AF recurrence with a sensitivity of 70.59% and specificity of 90.48%. A cut-off value of 277.65 ng/mL for anti-M2-R level predicted AF recurrence with a sensitivity of 70.59% and specificity of 95.24%. Conclusion Preprocedural serum anti-β1-R and anti-M2-R levels are independent predictors of late AF recurrence following cryoballoon-based PVI in paroxysmal AF patients. Detection of preprocedural anti-β1-R and anti-M2-R levels may serve as a novel method for determination of paroxysmal AF patients who may not benefit from cryoballoon-based PVI. [ABSTRACT FROM AUTHOR]

IRA-CTO and VT Ablation Introduction In patients with a prior myocardial infarction (MI), angiographic predictors of ventricular tachycardia (VT) recurrence after ablation are lacking. Recently, a proarrhythmic effect of a chronic total occlusion (CTO) in a coronary artery has been suggested. Methods and Results A total of 191 patients with prior MI were referred to our Hospital between 2010 and June 2013 for a first ablation of VT. Of these, 84 patients (44%) with stable coronary artery disease that underwent a coronary angiography during the index hospitalization were included in this study. A CTO in an infarct-related artery (IRA-CTO) was present in 47 patients (56%). Patients with and without IRA-CTO did not differ in terms of comorbidities, severity of heart failure, presentation of VT or acute outcome of ablation, that was completely successful in 93% of cases. At electroanatomic mapping, IRA-CTO was associated with greater scar and especially with greater area of border zone (34 cm2 vs. 19 cm2, P = 0.001). Median follow-up was 19 months (IQR 18). At follow-up, patients with IRA-CTO had a significantly higher rate of VT recurrence (47% vs. 16%, P = 0.003). At multivariate analysis, IRA-CTO resulted to be an independent predictor of VT recurrence after ablation (HR 4.05, P = 0.004). Conclusions IRA-CTO is an independent predictor of VT recurrence after ablation and identifies a subgroup of patients with high recurrence rate despite a successful procedure. IRA-CTO is associated with greater scars and border zone area; however, this association does not completely justify its proarrhythmic effect. [ABSTRACT FROM AUTHOR]

Ablation Effectiveness Quotient Introduction Inability to predict clinical outcome despite acutely successful pulmonary vein isolation (PVI) remains the Achilles' heel of atrial fibrillation ablation (AFA). Arrhythmia recurrence is frequently due to recovery of radiofrequency (RF) ablation lesions believed to be complete at the original procedure. Objectives We hypothesized that a high ratio between post-AFA levels of serum high sensitivity cardiac troponin T (HScTnT), a highly specific marker of acute myocardial injury, and duration of RF application (the ablation effectiveness quotient, AEQ) would indicate effective ablation and correlate with early clinical success. Methods We prospectively measured HScTnT levels in 60 patients (42 [70%] male, 22 [37%] with paroxysmal AF [PAF], mean age 62.5 ± 10.6 years) 12-18 hours after AFA and calculated the AEQ for each. Patients were followed-up with ECGs and Holter monitors for recurrence of atrial tachyarrhythmia (AT). Results Early recurrence of AT within 6 months occurred in 22 (37%). AT recurrence was not significantly related to left atrial size or comorbidities, nor to RF time or HScTnT level. Mean AEQ was significantly lower in those with recurrence than those without (0.35 ± 0.14 ng/L/s vs. 0.45 ± 0.18 ng/L/s), P = 0.02. Subgroup analysis showed this finding was due to patients with PAF in whom early significance was maintained to one year, with an AEQ >0.4 ng/L/s having 75% sensitivity and 90% specificity in predicting freedom from AT. Conclusion A high AEQ correlates well with freedom from AT in patients with PAF in both the short and medium term. If confirmed in further studies, AEQ may become a useful marker of risk of AT post-AFA. [ABSTRACT FROM AUTHOR]

Long-Term Outcome of AF Ablation in MMV Patients Introduction It is unclear whether extended pulmonary vein antrum isolation (PVAI) plus nonpulmonary vein (non-PV) trigger elimination prevents more arrhythmia recurrence than PVAI alone in patients with mechanical mitral valve (MMV) undergoing AF ablation. This study compared the efficacy and long-term outcome of 2 ablation strategies-PVAI alone versus extended PVAI plus non-PV trigger elimination-for the treatment of AF in patients with MMV. Methods and Results One hundred and nine consecutive AF patients with MMV were divided into 2 groups: standard PVAI was performed in group 1 (N = 45); in group 2 (N = 64) PVAI was extended to the LA posterior wall, LA septum, and CS; and all non-PV triggers were eliminated. Patients were followed up for 3 years. At the 12th month, 7 (15.6%) patients in group 1, and 39 (60.9%) patients in group 2 were arrhythmia free (log-rank P < 0.001). Four patients (8.9%; 3 cases of AT and 1 case of AF) from group 1, and 12 patients (18.8%; 9 cases of AT, and 3 cases of AFL) from group 2 experienced very late recurrence. At 36 ± 7 months follow-up, the cumulative recurrence after a single procedure was 42/45 (93.3%) in group 1, and 37/64 (57.8%) in group 2 (log-rank P < 0.001). Conclusion Compared with the standard PVAI alone, a strategy including extended PVAI and non-PV trigger elimination is associated with a higher 12-month and long-term arrhythmia-free survival in patients with MMV undergoing AF ablation. Very late recurrence may occur years after the initial procedure with focal AT as the most common type of recurrent arrhythmia. [ABSTRACT FROM AUTHOR]

Mechanisms of Pulmonary Vein Reconnection After Radiofrequency Ablation of Atrial Fibrillation Introduction Pulmonary vein reconnection (PVR) is an important cause of AF recurrence after ablation. With the advent of force sensing catheters, catheter-tissue contact can be determined quantitatively. Since contact force (CF) plays a major role in determining the characteristics of RF lesion, we prospectively assessed the mechanisms of PVR with regard to catheter-contact and lesion distances in patients undergoing AF ablation. Methods and Results Forty symptomatic AF patients underwent wide circumferential PV isolation (PVI) with SmartTouch™ CF catheter. The exact locations of acute PVI and spontaneous or adenosine-provoked PVR were annotated on CARTO. One thousand nine hundred and twenty-six RF lesions isolated 153 PVs. PVR occurred in 35 (23%) PVs: 22 (63%) adenosine-provoked and 13 (37%) spontaneous. CF was significantly lower at PVR versus PVI sites for RF lesions within 6 mm from these sites: mean CF 5 versus 11 g (P < 0.0001) and force-time integral (FTI) 225 versus 415 gs (P < 0.0001); 86% of PVR occurred with a mean CF < 10 g (FTI < 400 gs); and the remaining 14% occurred at ablation sites with a long interlesion distance (≥5 mm) despite mean CF ≥ 10 g. Eighty percent of PVR sites were located anteriorly. There were no significant differences in regard to arrhythmia freedom between the patients without (69%) versus with PVR (67%; P = 1.0). Conclusions Acutely durable PVI can be achieved when RF lesions are delivered with a mean CF ≥ 10 g and an interlesion distance <5 mm. The majority of PVR occur anteriorly due to inadequate CF or long interlesion distances. [ABSTRACT FROM AUTHOR]

Interventricular Electrical Delay Introduction The left ventricular (LV) pacing site and the magnitude of the electrical delay within the LV, as expressed by prolonged QRS duration, are major determinants of cardiac resynchronization therapy (CRT) efficacy. We investigated the incremental value of positioning the LV lead in areas of late activation in order to enhance the response to CRT in patients with different degrees of QRS complex lengthening. Methods and Results This analysis was performed on 301 heart failure patients who received a CRT defibrillator. On implantation, the right ventricular (RV)-to-LV interval was measured as the delay between local activations recorded through the RV and LV leads in the final position. After 1 year, 171 (57%) patients displayed reverse LV remodeling, as measured by a ≥15% reduction in the LV end-systolic volume. Both the RV-to-LV interval and its percentage value corrected for the QRS duration were significantly associated with a positive response to CRT. An RV-to-LV interval >80 milliseconds and an RV-to-LV interval/QRS >58% yielded the best prediction of reverse remodeling. Although the response to CRT decreased with shorter QRS duration in the overall population, patients with an RV-to-LV interval >80 milliseconds showed a response rate >65% in all QRS subgroups. Conclusion A longer RV-to-LV interval is associated with reverse LV remodeling after CRT. On implantation attempts could be made to maximize it when selecting the LV lead position, especially in patients with shorter QRS duration, and thus less likely to respond positively to CRT. [ABSTRACT FROM AUTHOR]

Prediction Rule to Identify Patients at High Risk for Early Demise Following CRT Background In patients with advanced heart failure, the decision of whether to pursue cardiac resynchronization therapy (CRT) or to proceed directly to advanced heart failure therapies can be challenging. We sought to create a prediction rule to identify patients with advanced systolic heart failure at heightened risk of rapid deterioration despite receiving CRT. Methods Clinical data were collected on consecutive patients with advanced heart failure presenting for a new CRT device at the Cleveland Clinic between February 12, 2002 and July 8, 2008. Early demise was defined as death, left ventricular assist device, or heart transplant within 6 months following CRT implant. Using a multivariate model, variables associated with early demise were identified and a prediction rule created. Results A total of 879 patients were included of whom 47 met criteria for early demise. Using forward stepwise regression followed by a bootstrapping analysis, the final model included: left ventricular end-diastolic diameter ≥6.5 cm (OR 3.23 [1.72-6.06 g], P < 0.001), the presence of a non-left bundle branch block (non-LBBB) morphology (OR 2.18 [1.18-4.04, P = 0.013]), creatinine ≥1.5 mg/dL (OR 2.98 [1.52-5.49], P < 0.001), and lack of or intolerance to β-blocker use (OR 2.80 [1.46-5.39], P = 0.002). The specificity for ≥2 and ≥3 risk factors was 72.6% and 94.6%, respectively. Conclusions Left ventricular dilatation, the presence of a non-LBBB morphology, renal dysfunction, and lack of or intolerance to β-blockers are associated with early demise following CRT. In patients with at least 3 of these factors, bypassing CRT with early adoption of advanced heart failure therapies may be considered given the high specificity for rapid decline. [ABSTRACT FROM AUTHOR]

Real-Time Contact Force Sensing for Pulmonary Vein Isolation Introduction The additional benefit of contact force (CF) technology during pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) to improve mid-term clinical outcome is unclear. Methods and Results Eligible patients with symptomatic paroxysmal AF were enrolled in this prospective trial, comparing circular antral catheter ablation (guided by Carto 3 System, Biosense Webster) using either a new open-irrigated CF catheter (SmartTouch Thermocool, Biosense Webster) (CF group) or a non-CF open-irrigated catheter (EZ Steer Thermocool, Biosense Webster) (control group). Overall, 30 patients were enrolled in each group, with a standardized 12-month follow-up, free of antiarrhythmic therapy. Demographic, cardiovascular and anatomic characteristics were similar in both groups. Though complete PVI was eventually achieved in all cases in both groups, success using an exclusive anatomic approach was 80.0% in CF group versus 36.7% in control group ( P < 0.0001). CF use was associated with significant reductions in fluoroscopy exposure ( P < 0.01) and radiofrequency time ( P = 0.01). The incidence rates of AF recurrence were 10.5% (95% CI, 1.38-22.4) in the CF group, and 35.9% (95% CI, 12.4-59.4) in the control group (log rank test, P = 0.04). After adjustment on potential confounders, the use of CF catheter was found to be associated with a lower AF recurrence (OR 0.18, 95% CI 0.04-0.94, P = 0.04). Conclusion Our findings suggest a potential benefit of real-time CF sensing technology, in reducing AF recurrence during the first year after PVI. [ABSTRACT FROM AUTHOR]

Catheter-Tissue Contact Force Determines Atrial Electrogram Characteristics Introduction Electrogram (EGM) characteristics are used to infer catheter-tissue contact. We examined if (a) atrial EGM characteristics predicted CF and (b) compared the value of CF versus other surrogates for predicting lesion efficacy. Methods and Results Twelve paroxysmal AF patients underwent pulmonary vein isolation using radiofrequency (RF) ablation facilitated by a novel CF-sensing catheter. Operators were blinded to CF. EGM amplitude, width, and morphology were measured pre- and post-RF. At each RF site, average CF, force-time integral (FTI), impedance fall, time to impedance plateau, maximum power, catheter tip temperature, and total energy delivered were recorded. An effective lesion was defined based on previously validated EGM criteria for transmural lesions. There was a moderate correlation between CF and EGM amplitude (r = 0.19) and EGM width (r = −0.22). Pre-RF, EGM amplitude, and width had modest to poor discriminative capacity for identifying preablation CF (e.g., EGM amplitude identified CF>20 g with sensitivity and specificity of 67% and 60%, respectively). Preablation CF, FTI, and total energy delivered during RF were the only independent predictors of effective lesion formation. Neither pre-RF EGM amplitude/width nor power, temperature, and impedance changes during RF predicted effective lesion formation. An average CF >16 g or FTI >404 g*s had excellent sensitivity and specificity (>80%) for identifying an effective lesion. Conclusions EGM characteristics do not reliably predict either CF before the onset of RF, nor do they predict the likelihood of an effective lesion. CF parameters were superior to power, temperature, and impedance changes during RF in predicting lesion efficacy. [ABSTRACT FROM AUTHOR]

Single- versus Dual-Coil ICD Leads Background Current data on efficacy, safety and impact on clinical outcome of single- versus dual-coil implantable cardioverter-defibrillator (ICD) leads are limited and contradictory. Methods Defibrillation threshold (DFT) at implantation and first shock efficacy were compared in patients implanted with single- versus dual-coil ICD leads in MADIT-CRT. The risk for atrial tachyarrhythmias and all-cause mortality were evaluated. Short- (< 30 days after the implantation) and long-term (throughout the entire study duration) complications were assessed. Results Patients with dual-coil ICD leads had significantly lower DFTs compared to patients with single-coil ICD leads (17.6 ± 5.8 J vs 19.4 ± 6.1 J, P < 0.001). First shock efficacy was similar among patients with dual and single-coil ICD leads (89.6% vs 92.3%, P = 1.00). When comparing patients with dual versus single-coil ICD leads, there was no difference in the risk of atrial tachyarrhythmias (HR = 1.57, 95% CI: 0.81-3.02, P = 0.18), or in the risk of all-cause mortality (HR = 1.10, 95% CI: 0.58-2.07, P = 0.77). Patients implanted with single- or dual-coil ICD lead had similar short and long-term complication rates (short-term HR = 0.96, 95% CI: 0.56-1.65, P = 0.88, long-term procedure-related HR = 0.99, 95% CI: 0.62-1.59, P = 1.00, long-term ICD lead related: HR = 1.2, 95% CI: 0.5-2.9, P = 0.68) during the mean follow-up of 3.3 years. Conclusions Patients with single-coil ICD leads have slightly higher DFTs compared to those with dual-coil leads, but the efficacy, safety, and clinical impact on atrial tachyarrhythmias, and mortality is similar. Implantation of single-coil ICD leads may be favorable in most patients. [ABSTRACT FROM AUTHOR]

Left Atrial Sphericity Predicts AF Ablation Outcome Background Atrial fibrillation (AF) ablation outcome is mainly determined by atrial remodeling that, nowadays, is only estimated through clinical presentation (persistent vs. paroxysmal) and left atrial (LA) dimension. The aim of the study was to stage the atrial remodeling process using the Left Atrial Sphericity (LASP) and determine whether this technique may help to predict AF ablation outcome. Methods Consecutive patients who underwent contrast-enhanced cardiac magnetic resonance angiography before AF ablation were included in the study. Three-dimensional reconstruction of LA excluding pulmonary veins and the LA appendage was used to define the LA cavity. The LASP was automatically obtained with self-customized software. Results 106 patients were included and categorized in 3 groups (Gs): discoid-LA (G1), intermediate-LA (G2), and spherical-LA (G3). The G3 patients had larger LA anteroposterior diameter than G1 and G2 patients (47 ± 7 vs 43 ± 6 and 39 ± 5mm; P < 0.001), greater LA volume (90 ± 39 vs 86 ± 24 and 73 ± 20 mm; P = 0.012), and higher prevalence of persistent AF (75% vs 48% and 29%; P = 0.034) structural heart disease (75% vs 19% and 19%; P < 0.001), and AF recurrence at 12 months follow-up (58% vs 29% and 5%, P < 0.001). The LASP had linear correlation to predicted probability of recurrence. Multivariate analysis identified LASP (OR 1.320 [1.096-1.591], P = 0.004) and hypertension (OR 3.694 [1.282-10.645]; P = 0.016) as independent risk factors for arrhythmia recurrence. Conclusion Left Atrial Sphericity is a new independent predictor of recurrence after AF ablation and may be useful in selecting the best candidates for AF ablation. [ABSTRACT FROM AUTHOR]

Arrhythmia Inducibility Post-AF Ablation Introduction Prior reports demonstrate prognostic value in noninducibility of atrial arrhythmias after atrial fibrillation (AF) ablation and suggest their utility in guiding additional ablation lesion sets. The type and mechanism of induced atrial arrhythmias, their relationship to the underlying atrial substrate, and prognostic significance of induced organized atrial arrhythmias are unknown. Methods and Results One hundred forty-four patients (30 women; median age 60 years; 54% with paroxysmal AF) undergoing AF ablation (circumferential pulmonary vein isolation and focal ablation of nonvein triggers on isoproterenol) were evaluated prospectively. All underwent a standardized postablation induction protocol from the coronary sinus and right atrium: 15 beat burst pacing at 250 milliseconds and decrementing to 180 milliseconds. Sustained rhythms were defined as greater than 2 minutes Of 144 patients, 55 patients (38.2%) did not have sustained inducible arrhythmias. Fifty-two (36.1%) had inducible AF and 37 (25.7%) had inducible organized arrhythmias. A logistic regression analysis showed that age (OR 2.10 per decade; P = 0.003) and hypertension (OR 4.15; P = 0.009) were predictive of inducibility. However, inducibility of either AF or organized arrhythmias was not prognostic of clinical recurrence at 1 year postablation (P = 0.65). Furthermore, inducibility of organized arrhythmias did not predict clinical recurrence of an organized arrhythmia. Only LA size (OR 2.18; 95% CI 1.02-4.67; P = 0.04) and persistent AF (OR 2.43; 95% CI 1.09-5.40; P = 0.03) predicted atrial arrhythmia recurrence. Conclusions Multisite atrial burst pacing post-AF ablation induced organized rhythms in 25.7% and AF in 36.1% of patients after AF ablation. Hypertension and age predict inducibility of arrhythmias, but inducibility did not predict clinical recurrence in follow-up. Distinguishing organized atrial arrhythmias from AF did not yield any further prognostic information. The utility of aggressive stimulation protocols after AF ablation for prognosis and to guide therapy appears limited. [ABSTRACT FROM AUTHOR]

Catheter Ablation of Stable Ventricular Tachycardia Background In the Ventricular Tachycardia Ablation in Coronary Heart Disease (VTACH) study, an intention-to-treat approach was used and may have diminished the observed degree of treatment effect. We present a subanalysis of the VTACH study by treatment actually received. Methods and Results The VTACH study was a prospective, open, randomized controlled trial, undertaken in 16 European centers, comparing defibrillator implantation with and without ventricular tachycardia (VT) ablation in patients with stable VT, previous myocardial infarction, and reduced left-ventricular ejection fraction. Of the 52 patients in the ablation group, 7 (13%) did not receive VT ablation and 19% of patients assigned to implantable cardioverter defibrillator (ICD) only treatment group crossed over and had an ablation. The primary endpoint (first recurrence of any documented VT or ventricular fibrillation [VF]) was reached after a median of 19.5 months in the ablation group and 5.9 months in the ICD only group (P = 0.01). Overall, 685 VT/VF events occurred per year of follow-up in 22 patients of the ablation group and 4,986 events in 43 patients of the control group (P = 0.024). In the ICD only group, median numbers of VT/VF episodes were 25 (IQR 5.8-45.3) and 1.5 (IQR 0-24.8) per patient and year before and after crossover (n = 12), respectively. Conclusion On-treatment analysis of the VTACH study emphasizes the effectiveness of VT ablation in patients receiving ICD treatment because of monomorphic VT post myocardial infarction. VT ablation clearly prolonged time to recurrence of VT/VF episodes and markedly decreased VT/VF burden. [ABSTRACT FROM AUTHOR]

Late Gadolinium Enhancement and Arrhythmias. Introduction : The extent of left ventricular (LV) scar, characterized by late gadolinium enhancement cardiac MRI (LGE-CMR), has been shown to predict the occurrence of ventricular arrhythmias in implantable cardioverter defibrillator (ICD) recipients. However, the specificity of LGE-CMR for sudden cardiac death (SCD) versus non-SCD is unclear. The aim of this retrospective, observational study was to evaluate this relationship in a cohort of ICD recipients. Methods and Results : We included consecutive patients who had undergone LGE-CMR before ICD implantation over a 4-year period (2006-2009). Scar (defined as myocardium with a signal intensity ≥50% of the maximum in scar tissue) was characterized in terms of percent scar and number of transmural LV scar segments in a 17-segment model. The endpoints were appropriate ICD therapy and all-cause mortality. Sixty-four patients (average age 66 ± 11 years, 51 male, median LVEF 30%) were included. During 42 ± 13 months follow-up, appropriate ICD therapy occurred in 28 patients (44%), and 14 patients (22%) died. Number of transmural scar segments (P = 0.005) and percentage LV scar (P = 0.03) were both significantly associated with appropriate ICD therapy. However, neither number of transmural scar segments (P = 0.32) or percent LV scar (P = 0.59) was significantly associated with all-cause mortality. Conclusion : In this observational study, in medium-term follow-up, the extent of LV scar characterized by LGE-CMR was strongly associated with the occurrence of spontaneous ventricular arrhythmias but not all-cause mortality. We hypothesize that scar quantification by LGE-CMR may be more specific for SCD than non-SCD, and may prove a valuable tool for the selection of patients for ICD therapy. (J Cardiovasc Electrophysiol, Vol. 24, pp. 430-436, April 2013) [ABSTRACT FROM AUTHOR]

Real-World Data on the Lifespan of ICDs Introduction: Implantable cardioverter-defibrillator (ICD) longevity is crucial for both patients and public health systems because it determines the number of surgical ICD replacements, which can generally be considered an additional risk factor for complications, and the cost-effectiveness of ICD therapy. Our objective was to obtain insight into the 'real-world' longevities of implantable cardioverter-defibrillators, which quite often differ from those stated in the manufacturers' declarations. Methods and Results: On the basis of a prospective database, we analyzed all ICD implantations performed in our hospital from June 1988 to June 2009. We studied 980 patients (follow-up 58 ± 51 months) with 1,502 ICDs and all respective data until August 2010. We compared the percentage of still operating ICDs at different points in time in relation to manufacturers, types of device (single chamber 623, dual chamber 588, cardiac resynchronization therapy ICDs [CRT-D] 291), and amount of right ventricular pacing (VP). We found distinct differences between the mean lifespans of ICDs of different manufacturers (Biotronik 4.3 years, Sorin 4.5 years, Guidant/Boston Scientific 4.7 years, St. Jude Medical 5 years, Medtronic 5.8 years). CRT-D devices (hazard ratio [HR] 1.778, P = 0.0005) were associated with an elevated annual relative risk for device replacement while a decrease in the proportion of VP (HR 0.934 for each 10% decrease in VP, P < 0.0001) and Medtronic ICDs were associated with a reduced risk of device replacement (HR 0.544, P < 0.0001). Conclusion: CRT-Ds and an elevated percentage of VP are associated with a significantly elevated risk for device replacement, while Medtronic ICDs showed the longest lifespans. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1336-1342, December 2012) [ABSTRACT FROM AUTHOR]

Prognostic Impact of Inappropriate Shocks. Introduction: Recent studies suggest a worse impact of inappropriate shock therapies on the outcome of patients with an implantable cardioverter-defibrillator (ICD). However, it is not known whether the worse impact is attributed to the ICD shock itself or due to the underlying heart disease. The aim of the study was to evaluate the impact of inappropriate ICD shocks on clinical outcome by comparing ICD shocks triggered by atrial fibrillation (AF) with shocks caused by lead failure. Methods and Results: A total of 1,411 consecutive patients of the prospective single-center ICD-registry Ludwigshafen who underwent an ICD implantation between 1992 and 2008 for primary or secondary prevention of sudden cardiac death were analyzed. During the median follow-up of 3 years, 297 (21%) patients experienced inappropriate ICD shocks. Sixty percent of patients had inappropriate shocks due to AF and 24% due to lead defect or T-wave oversensing. Multiple ICD shocks (≥2) triggered by AF were associated with a worse prognosis, whereas a single shock due to AF or 1 or multiple shocks resulting from lead failure were not. ICD shocks caused by AF occurred more often in tandem with a serious adverse event than in patients with a lead failure (15% vs 6%, P < 0.05). Conclusion: Multiple ICD shocks triggered by AF are associated with a worse prognosis in ICD patients, whereas a single shock due to AF or shocks resulting from lead failure are not. These data support that the ICD shock itself has no worse impact on the outcome of ICD patients. (J Cardiovasc Electrophysiol, Vol. 23, pp. 735-740, July 2012) [ABSTRACT FROM AUTHOR]

Depression and Cardiac Resynchronization Therapy. Background: The relationship between depression and heart failure is neither coincidental nor trivial, since depression is a powerful predictor of re-hospitalization and mortality. We prospectively studied the prevalence and impact of depression on the clinical outcomes of patients attending for cardiac resynchronization therapy (CRT). We specifically examined whether patients with depression have a different rate of response to CRT and whether CRT has an effect on depressive symptoms. Methods: Sixty-eight recipients of CRT systems were included. The depressive status was evaluated before implant and after 6 months by a structured diagnostic interview measuring Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria of major depression and by a self-report questionnaire (Center for Epidemiological Studies Depression Scale, CES-D). The CRT response was assessed at 6 months by a clinical composite score. Results: At inclusion, DSM-IV criteria of major depression were identified in 41% of the population, while using the self-report questionnaire 65% were observed to have mild to major depressive symptoms (CES-D ≥ 16). Only 4 patients were taking antidepressants. At 6 months, 75% were considered responders to CRT. Response to CRT did not differ between those with and without depression at baseline. The rate of patients with depression at 6 months was significantly lower in responders to CRT compared with nonresponders. Conclusions: We found a high prevalence of depressive symptoms in patients receiving CRT systems. Patients with depression should not be excluded from CRT, because they demonstrate a similar rate of response than the persons without depression and the responders are less likely to be depressed at 6 months. (J Cardiovasc Electrophysiol, Vol. 23, pp. 631-636, June 2012) [ABSTRACT FROM AUTHOR]

Pacemakers and ICDs in Myotonic Dystrophy. Introduction: We assessed implant rates, indications, characteristics, and outcomes in patients with the neuromuscular disease, myotonic dystrophy type 1 (DM1) receiving a pacemaker or an implantable cardioverter-defibrillator (ICD). Methods and Results: Device use was evaluated in a prospective, multicenter registry of 406 genetically confirmed adult patients followed for 9.5 ± 3.2 years. Forty-six (11.3%) had or received a pacemaker and 21 (5.2%) received an ICD. Devices were primarily implanted for asymptomatic conduction abnormalities and left ventricular (LV) systolic dysfunction. However, 7 (15.2%) pacemakers were implanted for third-degree atrioventricular block and 6 (28.6%) ICDs were implanted for ventricular tachyarrhythmias (ventricular tachycardia [VT] or fibrillation [VF]). Patients receiving devices were older and more frequently had heart failure, LV systolic dysfunction, atrial tachyarrhythmias, and ECG conduction abnormalities compared to nondevice patients. Five (10.9%) pacemaker patients underwent upgrade to an ICD, 3 for LV systolic dysfunction, 1 for VT/VF, and 1 for progressive conduction disease. Seventeen (27.4%) of the 62 patients with devices were pacemaker-dependent at last follow-up. Three (14.3%) ICD patients had appropriate therapies. Twenty-four (52.2%) pacemaker patients died including 13 of respiratory failure and 7 of sudden death. Seven (33.3%) ICD patients died including 2 of respiratory failure and 3 of sudden death. The patients with ICDs and sudden death all had LV systolic dysfunction and 1 death was documented due to inappropriate therapies. Conclusions: DM1 patients commonly receive antiarrhythmia devices. The risk of VT/VF and sudden death suggests that ICDs rather than pacemakers should be considered for these patients. (J Cardiovasc Electrophysiol, Vol. 22, pp. 1369-1375, December 2011) [ABSTRACT FROM AUTHOR]