A worldwide survey on incidence, management, and prognosis of oesophageal fistula formation following atrial fibrillation catheter ablation: the POTTER-AF study.

AIMS: Oesophageal fistula represents a rare but dreadful complication of atrial fibrillation catheter ablation. Data on its incidence, management, and outcome are sparse. METHODS AND RESULTS: This international multicentre registry investigates the characteristics of oesophageal fistulae after treatment of atrial fibrillation by catheter ablation. A total of 553 729 catheter ablation procedures (radiofrequency: 62.9%, cryoballoon: 36.2%, other modalities: 0.9%) were performed, at 214 centres in 35 countries. In 78 centres 138 patients [0.025%, radiofrequency: 0.038%, cryoballoon: 0.0015% (P < 0.0001)] were diagnosed with an oesophageal fistula. Peri-procedural data were available for 118 patients (85.5%). Following catheter ablation, the median time to symptoms and the median time to diagnosis were 18 (7.75, 25; range: 0-60) days and 21 (15, 29.5; range: 2-63) days, respectively. The median time from symptom onset to oesophageal fistula diagnosis was 3 (1, 9; range: 0-42) days. The most common initial symptom was fever (59.3%). The diagnosis was established by chest computed tomography in 80.2% of patients. Oesophageal surgery was performed in 47.4% and direct endoscopic treatment in 19.8% and conservative treatment in 32.8% of patients. The overall mortality was 65.8%. Mortality following surgical (51.9%) or endoscopic treatment (56.5%) was significantly lower as compared to conservative management (89.5%) [odds ratio 7.463 (2.414, 23.072) P < 0.001]. CONCLUSION: Oesophageal fistula after catheter ablation of atrial fibrillation is rare and occurs mostly with the use of radiofrequency energy rather than cryoenergy. Mortality without surgical or endoscopic intervention is exceedingly high.

Simple and safe digitoxin dosing in heart failure based on data from the DIGIT-HF trial.

BACKGROUND: The present study aimed to develop a simple dosing score when starting the cardiac glycoside digitoxin in heart failure with reduced ejection fraction (HFrEF) employing first data from the randomized, double-blinded DIGIT-HF trial. METHODS AND RESULTS: In DIGIT-HF, digitoxin was started with a dose of 0.07 mg once daily (o.d.) in all patients. For score derivation, 317 patients were analyzed who had been randomized to digitoxin. In these patients, after scheduled determination of serum levels at study week 6, the digitoxin dose had remained unchanged or had been reduced to 0.05 mg o.d. (97% of patients) to achieve serum concentrations within a predefined range (10.5-23.6 nmol/l). In logistic regression analyses, sex, age, body mass index (BMI), and estimated glomerular filtration rate (eGFR) were associated with need for dose reduction and, therefore, selected for further developing the dosing score. Optimal cut-points were derived from ROC curve analyses. Finally, female sex, age ≥ 75 years, eGFR < 50 ml/min/1.73 m2, and BMI < 27 kg/m2 each were assigned one point for the digitoxin dosing score. A score of ≥ 1 indicated the need for dose reduction with sensitivity/specificity of 81.6%/49.7%, respectively. Accuracy was confirmed in a validation data set including 64 patients randomized to digitoxin yielding sensitivity/specificity of 87.5%/37.5%, respectively. CONCLUSION: In patients with HFrEF, treatment with digitoxin should be started at 0.05 mg o.d. in subjects with either female sex, eGFR < 50 ml/min/1.73m2, BMI < 27 kg/m2, or age ≥ 75 years. In any other patient, digitoxin may be safely started at 0.07 mg o.d.

Diagnostic yield of an insertable cardiac monitor in a large patient population.

Background: Insertable cardiac monitors (ICMs) are increasingly used for cardiac rhythm diagnosis with expanding indications. Little has been reported about their use and efficacy. Objective: The study sought to evaluate the clinical utility of a novel ICM (Biotronik BIOMONITOR III) including the time to diagnosis in unselected patients with different ICM indications. Methods: Patients from 2 prospective clinical studies were included to determine the diagnostic yield of the ICM. The primary endpoint was time to clinical diagnosis per implant indication or to the first change in atrial fibrillation (AF) therapy. Results: A total of 632 patients were included with a mean follow-up of 233 ± 168 days. Of 384 patients with (pre)syncope, 34.2% had a diagnosis at 1 year. The most frequent therapy was permanent pacemaker implantation. Of 133 patients with cryptogenic stroke, 16.6% had an AF diagnosis at 1 year, resulting in oral anticoagulation. Of 49 patients with an indication for AF monitoring, 41.0% had a relevant change in AF therapy based on ICM data at 1 year. Of 66 patients with other indications, 35.4% received a rhythm diagnosis at 1 year. Moreover, 6.5% of the cohort had additional diagnoses: 26 of 384 patients with syncope, 8 of 133 patients with cryptogenic stroke, and 7 of 49 patients with AF monitoring. Conclusion: In a large unselected patient population with heterogeneous ICM indications, the primary endpoint of rhythm diagnosis was achieved in ∼1 in 4, and additional clinically relevant findings was achieved in 6.5% of patients at short-term follow-up.

Effect of concomitant Renal DeNervation and cardiac ablation on Atrial Fibrillation recurrence - RDN+AF study.

BACKGROUND: Renal denervation (RDN) can reduce cardiac sympathetic activity maintained by arterial hypertension (aHT). Its potential antiarrhythmic effect on rhythm outcome in patients with multi-drug resistant aHT undergoing catheter ablation for atrial fibrillation (AF) is unclear. METHODS: The RDN+AF study was a prospective, randomized, two-center trial. Patients with paroxysmal or persistent AF and uncontrolled aHT (mean systolic 24-h ambulatory BP > 135 mmHg) despite taking at least three antihypertensive drugs were enrolled. Patients were 1:2 randomized to either RDN+AF ablation or AF-only ablation. Primary endpoint was freedom from any AF episode > 2 min at 12 months assessed by implantable loop recorder (ILR) or 7d-holter electrocardiogram. Secondary endpoints included rhythm outcome at 24 months, blood pressure control, periprocedural complications, and renovascular safety. RESULTS: The study randomized 61 patients (mean age 65 ± 9 years, 53% men). At 12 months, RDN+AF patients tended to have a greater decrease in ambulatory BPs but did not reach statistical significance. No differences in rhythm outcome were observed. Freedom from AF recurrence in the RDN+AF and AF-only group measured 61% versus 53% p = .622 at 12 months and 39% versus 47% p = .927 at 24 months, respectively. Periprocedural complications occurred in 9/61 patients (15%). No patient died. CONCLUSION: Among patients with multidrug-resistant aHT and paroxysmal or persistent AF, concomitant RDN+AF ablation was not associated with better blood pressure control or rhythm outcome in comparison to AF-only ablation and medical therapy.

Magnetic resonance imaging-guided conventional catheter ablation of isthmus-dependent atrial flutter using active catheter imaging.

Background: Interventional cardiac magnetic resonance (iCMR) has been established as a radiation-free alternative compared to standard fluoroscopy-guided catheter ablation for cavotricuspid isthmus (CTI)-dependent atrial flutter to image anatomy, structural alterations, and further catheter guidance. Objective: The purpose of this study was to explore the safety, feasibility, and efficacy of CTI ablations performed completely in the iCMR suite using active catheter imaging. Methods: Consecutive patients underwent iCMR-guided catheter ablation for CTI-dependent atrial flutter. Procedures were performed in a 1.5-T magnetic resonance (MR) imaging unit with MR-conditional ablation catheters. Catheter guidance was achieved using active catheter imaging via integrated MR receive tip coils. Acute success, periprocedural complications, and short-term follow-up were collected for further analysis. Results: All patients (N = 15; 73% male; median age 70 years; interquartile range [67-82]) achieved acute procedural success without any complication. Median procedural time was 43 minutes [33-58] with median radiofrequency delivery time of 18 minutes [12-26]. Postprocedural lesion visualization scanning was completed in a median of 32 minutes [10-42]. None of the patients with 6-month follow-up had atrial flutter recurrence. Conclusion: In the iCMR suite, CTI-dependent atrial flutter ablation could be achieved safely using active catheter imaging without any complication. It further allows detailed anatomic visualization of the CTI, intraprocedural lesion visualization, and exclusion of pericardial effusion.

Clinical Outcomes in Patients With Dilated Cardiomyopathy and Ventricular Tachycardia.

BACKGROUND: Recurrent ventricular tachycardia (VT) due to dilated cardiomyopathy (DCM) is difficult to treat, and long-term outcome data are limited. OBJECTIVES: The aim of this study was to identify predictors of mortality or heart transplantation (HTx) and VT recurrence. METHODS: Consecutive patients with DCM accepted for radiofrequency catheter ablation (RFCA) of VT at 9 centers were prospectively enrolled and followed. RESULTS: Of 281 consecutive patients (mean age 60 ± 13 years, 85% men, mean left ventricular ejection fraction [LVEF] 36% ± 12%), 35% had VT storm, 20% had incessant VT, and amiodarone was unsuccessful in 68%. During follow-up of 21 months (IQR: 6-30 months), 67 patients (24%) died or underwent HTx, and 138 (49%) had VT recurrence (45 within 30 days, defined as early); the 4-year rate of VT recurrence or mortality or HTx was 70%. Independent predictors of mortality or HTx were early VT recurrence (HR: 2.92; 95% CI: 1.37-6.21; P < 0.01), amiodarone at discharge (HR: 3.23; 95% CI: 1.43-7.33; P < 0.01), renal dysfunction (HR: 1.92; 95% CI: 1.01-3.64; P = 0.046), and LVEF (HR: 1.36; 95% CI: 1.0-1.84; P = 0.052). LVEF ≤32% identified patients at risk for mortality or HTx (area under the curve: 0.75). Mortality or HTx per 100 person-years was 40.4 events after early, compared with 14.2 events after later VT recurrence and 8.5 events with no VT recurrence after RFCA (P < 0.01 for both). Patients with early recurrence and LVEFs ≤32% had a 1-year rate of mortality or HTx of 55%. VT recurrence was predicted by prior implantable cardioverter-defibrillator shocks, basal anteroseptal VT origin, and procedural failure but not LVEF. CONCLUSIONS: Patients with DCM needing RFCA for VT are a high-risk group. Following RFCA, approximately one-half remain free of VT recurrence. Early VT recurrence with LVEF ≤32% identifies those at very high risk for mortality or HTx, and screening for mechanical support or HTx should be considered. Late VT recurrence after RFCA does not predict worse outcome.

New-generation miniaturized insertable cardiac monitor with a long sensing vector: Insertion procedure, sensing performance, and home monitoring transmission success in a real-world population.

Background: Insertable cardiac monitors (ICMs) require an invasive procedure and are used for purely diagnostic purposes. Therefore, simplicity of the insertion procedure, low complication rate, long-term patient acceptance, sensing quality, and reliable remote monitoring are of great importance. Objective: To evaluate a novel ICM (BIOMONITOR III) regarding all these aspects. Methods: BIOMONITOR III has a miniaturized profile, long sensing vector (≈70 mm), a fast insertion tool for pocket formation and ICM placement in 1 step, and daily automatic Home Monitoring (HM) function. We evaluated the insertion procedure, complication rate, patient acceptance, sensing quality, and HM performance in 653 patients with BIOMONITOR III inserted for any ICM indication within 2 ongoing studies involving 51 sites in 11 countries. Results: The median time from skin incision to wound closure was 4.0 minutes (interquartile range, 2.3-6.2 minutes). Median follow-up period was 274 days (interquartile range, 175-342 days). Serious adverse device-related events occurred in 6 patients (0.9%). No deep infections were reported in 334 patients without antibiotic prophylaxis. The wearing comfort was good or excellent in ≈95%. The mean R-wave amplitude (0.73 mV) and HM transmission rate (≈94% of days) were stable over 1.5 years. R-wave amplitudes were larger (mean 0.80 vs 0.62 mV, P < .001) and noise burden was lower (median 3.7 vs 14.5 minutes/day, P < .001) for ICM insertions parallel to the heart's long axis (54.2%) vs parasternal (41.3%). A gross visibility of P waves was 95.1%. Conclusion: The study demonstrated fast insertion times, low complication rate, high patient acceptance, and favorable long-term sensing and HM performance of the ICM.

Simple periprocedural precautions to reduce Doppler microembolic signals during AF ablation.

BACKGROUND: Doppler microembolic signals (MES) occur during atrial fibrillation ablation despite of permanent flushed transseptal sheaths, frequent controls of periprocedural coagulation status and the use of irrigated ablation catheters PURPOSE: To investigate the number and type of MES depending on the procedure time, prespecified procedure steps, the activated clotting time (ACT) during the ablation procedure and the catheter contact force. METHODS: In a prospective trial, 53 consecutive atrial fibrillation patients underwent pulmonary vein isolation by super-irrigated "point-by-point" ablation. All patients underwent a periinterventional, continuous transcranial Doppler examination (TCD) of the bilateral middle cerebral arteries during the complete ablation procedure. RESULTS: An average of 686±226 microembolic signals were detected by permanent transcranial Doppler. Thereby, 569±208 signals were differentiated as gaseous and 117±31 as solid MES. The number of MES with regard to defined procedure steps were as follows: gaseous: [transseptal puncture, 26 ± 28; sheath flushing, 24±12; catheter change, 21±11; angiography, 101±28; mapping, 9±9; ablation, 439±192; protamine administration, 0±0]; solid: [transseptal puncture, 8±8; sheath flushing, 9±5; catheter replacement, 6±6; angiography, not measurable; mapping, 2±5; ablation, 41±22; protamine administration, 0±0]. Significantly less MES occurred with shorter procedure time, higher ACT and the use of tissue contact force monitoring. CONCLUSION: The current study demonstrates that during atrial fibrillation ablation using irrigated, "point-by-point" RF ablation, masses of microembolic signals are detected in transcranial ultrasound especially in the period of RF current application. The number of MES depends on the total procedure time and the reached ACT during ablation. The use of contact force monitoring might reduce MES during RF ablation.

Low-Voltage Myocardium-Guided Ablation Trial of Persistent Atrial Fibrillation.

Low-Voltage Myocardium Ablation Trial of Persistent AFWe investigated ablation approaches in 324 patients with persistent AF by comparing ablation with PVI alone and PVI plus individualized SM. Patients had electrocardiogram recordings over 12 months of observation. Recurrent AF was documented in 50% of PVI only and 35% of PVI+SM patients. AEs occurred in six PVI+SM versus three PVI-alone patients.

Left Atrial Isolation and Appendage Occlusion in Patients With Atrial Fibrillation at End-Stage Left Atrial Fibrotic Disease.

[Figure: see text].

Comparison of uninterrupted direct oral anticoagulation with vitamin-K antagonists during AF-ablation in the clinical routine. A single center register.

BACKGROUND: Uninterrupted direct oral anticoagulation (DOAC) in AF-ablation is recommended, proven by randomized trials. The outcome and the periinterventional differences between DOACs and VKA in the real world clinical practice are discussed controversial. HYPOTHESIS: To investigate efficiency and safety of uninterrupted DOAC therapy compared to VKA during AF-Ablation in real world setting with a focus on periinterventional heparin dosage.

Left atrial phasic transport function closely correlates with fibrotic and arrhythmogenic atrial tissue degeneration in atrial fibrillation patients: cardiac magnetic resonance feature tracking and voltage mapping.

AIMS: To characterize the association of phasic left atrial (LA) transport function and LA fibrosis guided by multimodality imaging containing cardiac magnetic resonance imaging (CMR) feature tracking and bipolar voltage mapping. METHODS AND RESULTS: Consecutive patients presenting for first-time ablation of atrial fibrillation (AF) were prospectively enrolled. Each patient underwent CMR prior to the ablation procedure. LA phasic indexed volumes (LA-Vi) and emptying fractions (LA-EF) were calculated and CMR feature tracking guided LA wall motion analysis was performed. LA bipolar voltage mapping was carried out in sinus rhythm to find areas of low voltage as a surrogate for fibrosis and arrhythmogenesis. One hundred and sixty-eight patients were enrolled. Low-voltage areas (LVAs) were present in 70 patients (42%). Contrary to LA volume, CMR based LA-EF [odds ratio (OR) 0.88, 95% confidence interval (CI) 0.80-0.96, P = 0.005] and LA booster pump strain rate (SR) (OR 0.98, 95% CI 0.97-0.99, P = 0.001) significantly predicted presence and extent of LVA in multivariate logistic regression analysis for patients scanned in SR. In receiver operating characteristic analysis, LA-EF <40% carried a sensitivity of 83% and specificity of 76% (area under the curve 0.8; 95% CI 0.71-0.89) to predict presence of LVA. For patients scanned in AF only minimal LA-Vi on CMR (OR: 1.06; 95% CI: 1.02-1.10; P = 0.002) predicted presence of LVA. CONCLUSION: For patients scanned in SR LA-EF and LA booster pump SR are closely linked to the presence and extent of LA LVA.

Left atrial fibrosis predicts left ventricular ejection fraction response after atrial fibrillation ablation in heart failure patients: the Fibrosis-HF Study.

AIMS: Atrial fibrillation (AF) and heart failure (HF) often coexist. Catheter ablation has been reported to restore left ventricular (LV) function but patients benefit differently. This study investigated the correlation between left atrial (LA) fibrosis extent and LV ejection fraction (LVEF) recovery after AF ablation. METHODS AND RESULTS: In this study, 103 patients [64 years, 69% men, 79% persistent AF, LVEF 33% interquartile range (IQR) (25-38)] undergoing first time AF ablation were investigated. Identification of LA fibrosis and selection of ablation strategy were based on sinus rhythm voltage mapping. Continuous rhythm monitoring was used to assess ablation success. Improvement in post-ablation LVEF was measured as primary study endpoint. An absolute increase in post-ablation LVEF ≥10% was defined as 'Super Response'. Left atrial fibrosis was present in 38% of patients. After ablation LVEF increased by absolute 15% (IQR 6-25) (P < 0.001). Left ventricular ejection fraction improvement was higher in patients without LA fibrosis [15% (IQR 10-25) vs. 10% (IQR 0-20), P < 0.001]. An inverse correlation between LVEF improvement and the extent of LA fibrosis was found (R2 = 0.931). In multivariate analysis, the presence of LA fibrosis was the only independent predictor for failing LVEF improvement [odds ratio 7.2 (95% confidence interval 2.2-23.4), P < 0.001]. Echocardiographic 'Super Response' was observed in 55/64 (86%) patients without and 21/39 (54%) patients with LA fibrosis, respectively (P < 0.001). CONCLUSION: Presence and extent of LA fibrosis predict LVEF response in HF patients undergoing AF ablation. The assessment of LA fibrosis may impact prognostic stratification and clinical management in HF patients with AF.

Electrophysiological findings during atrial fibrillation reablation: Extending from pulmonary vein reconnection to sequential bipolar voltage map information.

BACKGROUND: Left atrial substrate modification targeting low voltage zones (LVZ) is an ablation strategy that-in addition to pulmonary vein (PV) isolation-tries to eliminate arrhythmogenic mechanisms harbored in such tissue. Electrophysiological findings at reablation include (a) PV reconnection, (b) reconnection over previous substrate ablation, and (c) de-novo LVZ. OBJECTIVE: To study, prevalence and contribution of these arrhythmogenic electrophysiological entities in patients with atrial fibrillation (AF) recurrences. METHODS: Consecutive patients with highly symptomatic AF undergoing index and reablation were included (n = 113). In all patients' PV reconnection, reconnection over previous substrate ablation and spontaneous de-novo LVZ were quantitatively assessed and integrated into an individual reablation strategy. Follow-up was based on continuous device monitoring. RESULTS: At re-do procedure, 45 out of 113 (39.8%) patients showed PV reconnection as the only electrophysiological abnormality. Reconduction over previous lines was the only electrophysiological abnormality in 8 out of 113 (7.1%) patients. Spontaneous de-novo LVZ was the only electrophysiological abnormality in 12 out of 113 (10.6%) patients. Combined findings of PV reconnection, line reconduction, and/or spontaneous de-novo LVZ were seen in 40 out of 113 (35.4%) patients. No detectable electrophysiological abnormality was observed in 8 out of 113 (7.1%) patients. In univariate analysis, none of the tested electrophysiological characteristics independently predicted the outcome after re-do. CONCLUSIONS: In patients undergoing reablation, we could show that reconduction over previous substrate ablation as well as the development of new low voltage areas are frequent findings besides classical PV reconnection-without a clear leading cause for recurrences. These findings impact reablation strategies as well as the strategic focus during index procedures.

A collective European experience with left atrial appendage suture ligation using the LARIAT+ device.

AIMS: We report the collective European experience of percutaneous left atrial appendage (LAA) suture ligation using the recent generation LARIAT+ suture delivery device. METHODS AND RESULTS: A total of 141 patients with non-valvular atrial fibrillation and contraindication to oral anticoagulation (OAC), thrombo-embolic events despite OAC or electrical LAA isolation were enrolled at seven European hospitals to undergo LAA ligation. Patients were followed up by clinical visits and transoesophageal echocardiography (TOE) following LAA closure. Left atrial appendage ligation was completed in 138/141 patients (97.8%). Three patients did not undergo attempted deployment of the LARIAT device due to pericardial adhesion after previous epicardial ventricular tachycardia ablation (n = 1), a pericardial access-related complication (n = 1), and multiple posterior LAA lobes (n = 1). Serious 30-day procedural adverse events occurred in 4/141 patients (2.8%). There were two device-related LAA perforations (1.4%) not resulting in any corrective intervention as the LAA was completely sealed with the LARIAT. Minor adverse events occurred in 19 patients (13.5%), including two pericardial effusions due to procedure-related pericarditis requiring pericardiocentesis. Transoesophageal echocardiography was performed after LAA ligation in 103/138 patients (74.6%) after a mean of 181 ± 72 days. Complete LAA closure was documented in 100 patients (97.1%). Two patients (1.8% of patients with follow-up) experienced a transient ischaemic attack at 4 and 7 months follow-up, although there was no leak observed with TOE. There were two deaths during long-term follow-up which were both not device related. CONCLUSION: Initial experience with the LARIAT+ device demonstrates feasibility of LAA exclusion. Further larger prospective studies with longer follow-up are warranted.

Role of inducibility and its dynamic change in the outcome of catheter ablation of atrial fibrillation: a single center prospective study.

BACKGROUND: The role of atrial arrhythmia inducibility as an endpoint of catheter ablation of atrial fibrillation (AF) has been a controversial subject in many studies. Our goal is to evaluate the significance of inducibility, the impact of multiple sites or protocols of stimulation or the change in inducibility status in a prospective study including patients with AF undergoing first catheter ablation. METHODS: We studied 170 consecutive patients with AF (62.9% paroxysmal) undergoing catheter ablation. All patients underwent two separate stimulation protocols before and after the ablation from the coronary sinus ostium and the left atrial appendage: burst pacing at 300, 250, 200 milliseconds (or until refractoriness) for 10 seconds and ramp decrementing from 300 to 200 milliseconds in increments of 10 milliseconds every three beats for 10 seconds. Inducibility was defined as any sustained AF or organized atrial tachycardia (AT) lasting >30 seconds. RESULTS: We had AF/AT inducibility in 55 patients at baseline compared to 36 following ablation. After a mean of 41, 3 months follow-up, 115 patients were free of AF. Inducibility before or after the ablation or change in inducibility status did not influence AF recurrence. There were no significant differences regarding paroxysmal or persistent patients with AF. CONCLUSIONS: Non-inducibility of atrial arrhythmia or change in inducibility status following pulmonary vein (PV) isolation and substrate modification are not associated with long-term freedom from recurrent arrhythmia. Therefore, the use of induction of an endpoint in AF ablation is limited.

[Coronary sinus mapping of the optimal LV electrode position]. / Koronarsinus-Mapping der optimalen linksventrikulären Elektrodenposition.

Cardiac resynchronization therapy (CRT) is an established pillar of treatment for patients with chronic heart failure. However, 30% of patients do not respond adequately to this type of therapy. One possible reason for this is a nonoptimal left ventricular stimulation site. This review focuses on possibilities of visualization of the coronary vein anatomy and its role in the determination of the electrical and mechanical dyssynchrony to optimize the therapeutic success of the resynchronization therapy. In addition, the clinical implication and the perspectives of a dedicated mapping of the coronary vein are discussed. Finally, a brief outlook on current and future technologies for improving this form of therapy is given.

Continuous monitoring after atrial fibrillation ablation: the LINQ AF study.

Aims: To study device performance, arrhythmia recurrence characteristics, and methods of outcome assessment using a novel implantable cardiac monitor (ICM) in patients undergoing ablation for atrial fibrillation (AF). Methods and results: In 419 consecutive patients undergoing first-time catheter ablation for symptomatic paroxysmal (n = 224) or persistent (n = 195) AF an ICM was injected at the end of the procedure. Telemedicine staff ensured full episode transmission coverage and manually evaluated all automatic arrhythmia episodes. Device detection metrics were calculated for ≥2, ≥6, and ≥10 min AF detection durations. Four methods of outcome assessment were studied: continuous recurrence analysis, discontinuous recurrence analysis, AF-burden analysis, and analysis of individual rhythm profiles. A total of 43 673 automatic AF episodes were transmitted over a follow-up of 15 ± 6 months. Episode-based positive predictive values changed significantly with longer AF detection durations (70.5% for ≥2 min, 81.8% for ≥6 min, and 85.9% for ≥10 min). Patients with exclusive short episode recurrences (≥2 to <6 min) were rare and their arrhythmia detection was clinically irrelevant. Different methods of outcome assessment showed a large variation (46-79%) in ablation success. Individual rhythm characteristics and subclinical AF added to this inconsistency. Analysis of AF-burden and individual rhythm profiles were least influenced and showed successful treatment in 60-70% of the patients. Conclusion: We suggest AF detection duration >6 min and AF burden >0.1% as a standardized outcome definition for AF studies to come in the future.

Characterizing left ventricular mechanical and electrical activation in patients with normal and impaired systolic function using a non-fluoroscopic cardiovascular navigation system.

PURPOSE: Cardiac disease frequently has a degenerative effect on cardiac pump function and regional myocardial contraction. Therefore, an accurate assessment of regional wall motion is a measure of the extent and severity of the disease. We sought to further validate an intra-operative, sensor-based technology for measuring wall motion and strain by characterizing left ventricular (LV) mechanical and electrical activation patterns in patients with normal (NSF) and impaired systolic function (ISF). METHODS: NSF (n = 10; ejection fraction = 62.9 ± 6.1%) and ISF (n = 18; ejection fraction = 35.1 ± 13.6%) patients underwent simultaneous electrical and motion mapping of the LV endocardium using electroanatomical mapping and navigational systems (EnSite™ NavX™ and MediGuide™, Abbott). Motion trajectories, strain profiles, and activation times were calculated over the six standard LV walls. RESULTS: NSF patients had significantly greater motion and systolic strains across all LV walls than ISF patients. LV walls with low-voltage areas showed less motion and systolic strain than walls with normal voltage. LV electrical dyssynchrony was significantly smaller in NSF and ISF patients with narrow-QRS complexes than ISF patients with wide-QRS complexes, but mechanical dyssynchrony was larger in all ISF patients than NSF patients. The latest mechanical activation was most often the lateral/posterior walls in NSF and wide-QRS ISF patients but varied in narrow-QRS ISF patients. CONCLUSIONS: This intra-operative technique can be used to characterize LV wall motion and strain in patients with impaired systolic function. This technique may be utilized clinically to provide individually tailored LV lead positioning at the region of latest mechanical activation for patients undergoing cardiac resynchronization therapy. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov . Unique identifier: NCT01629160.