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Despite technological advancements and evolving ablation strategies, atrial fibrillation catheter ablation outcome remains suboptimal for a cohort of patients. Imaging-based biomarkers have the potential to play a pivotal role in the overall assessment and prognostic stratification of AF patients, allowing for tailored treatments and individualized care. Alongside consolidated evaluation parameters, novel imaging biomarkers that can detect and stage the remodelling process and correlate it to electrophysiological phenomena are emerging. This review aims to provide a better understanding of the different types of atrial substrate, and how Computed Tomography can be used as a pre-ablation risk stratification tool by assessing the various novel imaging biomarkers, providing a valuable insight into the mechanisms that sustain AF and potentially allowing for a patient-specific ablation strategy.

Catheter ablation is a well-established treatment for patients with AF in whom sinus rhythm is desired. Both radiofrequency catheter ablation and cryoablation are widely performed, rapidly developing techniques. Convergent ablation is a novel hybrid technique combining an endocardial radiofrequency ablation with a minimally invasive epicardial surgical ablation. Some suggest that hybrid ablation may be more effective than lone endocardial ablation in achieving the elusive goal of maintaining sinus rhythm in patients with non-paroxysmal AF. In this article, the authors examine the safety and efficacy of catheter ablation and convergent ablation for long-standing, persistent AF. We also outline the crucial role that electrophysiologists play, not only as a procedure operator, but also as the coordinator and developer of this multidisciplinary service.

Objectives The goal of this study was to assess the impact of triventricular pacing (Tri-V) on long-term survival. Background Biventricular pacing (Bi-V) is an important adjunctive treatment in advanced heart failure, but almost one-third of patients experience no improvement with this therapy and are labeled as nonresponders. Adding a third ventricular lead (Tri-V) has been shown to be feasible and provides favorable acute results when assessed by using echocardiographic, hemodynamic, and clinical endpoints. However, the long-term effects of Tri-V pacing and how it affects long-term survival remains unknown. Methods This single-center, propensity score–matched cohort study compared 34 patients with advanced heart failure who underwent implantation with Tri-V devices versus 34 control subjects treated with Bi-V pacing. Clinical outcomes during a median of 2,478 days (IQR: 1,183 to 3,214 days) were compared. Results Tri-V–treated patients compared with Bi-V–treated patients presented with a trend for shorter battery longevity (time to box change, 1,758 ± 360 days vs. 1,993 ± 408 days; p = 0.072). Incidence of lead dislodgement (Tri-V vs. Bi-V, 0.86 vs. 1.10 per 100 patient-years; p = 0.742), device-related infection (Tri-V vs. Bi-V, 1.83 vs. 1.76 per 100 patient-years; p = 0.996), and refractory phrenic nerve capture (Tri-V vs. Bi-V, 0.48 vs. 1.84 per 100 patient-years; p = 0.341) was comparable in the 2 groups. Episodes of ventricular arrhythmia requiring implantable cardioverter-defibrillator intervention occurred more frequently in the Bi-V group versus the Tri-V group (6.55 vs. 16.88 per 100 patient-years; adjusted hazard ratio: 0.31; 95% confidence interval: 0.14 to 0.66; p = 0.002). Lower all-cause mortality and heart transplant was observed in the Tri-V group compared with the Bi-V group (6.99 vs. 11.92 per 100 patient-years; adjusted hazard ratio: 0.44; 95% confidence interval: 0.23 to 0.85; p = 0.015). Conclusions Tri-V displayed a similar safety profile compared with Bi-V and was associated with potential benefits regarding long-term survival and ventricular arrhythmia burden.

Aims Differences of action potential duration (APD) in regions of myocardial scar and their borderzones are poorly defined in the intact human heart. Heterogeneities in APD may play an important role in the generation of ventricular tachycardia (VT) by creating regions of functional block. We aimed to investigate the transmural and planar differences of APD in patients admitted for VT ablation. Methods and results Six patients (median age 53 years, five male); (median ejection fraction 35%), were studied. Endocardial (Endo) and epicardial (Epi) 3D electroanatomic mapping was performed. A bipolar voltage of 1.5 mV as normal. Decapolar catheters were positioned transmurally across the scar borderzone to assess differences of APD and repolarization time (RT) during restitution pacing from Endo and Epi. Epi APD was 173 ms in normal tissue vs. 187 ms at scar borderzone and 210 ms in dense scar (P

Aim Device infection is a serious complication and is considered procedure-related if occurring within 12 months of an intervention. We analysed the effectiveness of a simple infection-control protocol (ICP) at reducing cardiac device infections (CDIs) in a tertiary referral centre. Methods and results Prior to the introduction of a new ICP, we retrospectively analysed all simple and complex device implants, related procedures, and infections over a 3-year period. A new protocol was implemented from November 2007, including antibiotic prophylaxis determined by risk stratification, improved glycaemic control, specific skin preparation, and closure techniques, as well as different diathermy settings. Follow-up data for all patients were collected. Risk factors for infection were compared between pre- and post-intervention groups to ensure that the populations were comparable. A cost analysis of CDI and a review of the commonly identified micro-organisms were also undertaken. One thousand seven hundred and ninety-eight procedures were performed between November 2004 and November 2007 and 981 procedures between November 2007 and May 2009. There were no significant differences in the risk factors for infection between the two groups. Following the introduction of the ICP, there was a 54% reduction in the incidence of CDI from 1.3 to 0.6% ( P < 0.03; CI 0.25, 1.36). Most patients with CDI had negative blood cultures or grew Staphylococcus sp. The average cost was £30 958.40 per infection incident and the cost of the new ICP was minimal. Conclusions A significant reduction in CDI can be achieved with the introduction of a simple ICP with substantial cost savings.

Aims Despite the increasing number of device implants worldwide, little is known about the early and late complications of cardiac resynchronisation therapy (CRT) or the incidence of these complications in patients with different heart failure aetiologies. We aim to determine procedural success and early and late complications in CRT patients. Methods and results All early ( 90 days) complications occurring over 490 consecutive CRT procedures in 402 patients, from a large single-centre registry between 2000 and 2009 were analysed. Mean follow-up duration was 1012 ± 610 days. In addition, procedural data and long-term left ventricular (LV) lead performance were examined. The mean age of patients was 65 ± 15 years, 31% were female. The majority of devices (70%) were CRT-defibrillators. Left ventricular lead implantation was achieved after one or more than one attempt in 96.7% of patients (first procedure was successful in 95.1%). The incidence of early and late complications was 9.4% and 6.1% respectively. Infection and lead displacement were the most common complications. Dilated cardiomyopathy (DCM) was associated with significantly more complications than ischaemic cardiomyopathy ( P = 0.01) and these occurred later in the DCM population. Long-term LV lead performance was comparable with that of right atrial and ventricular leads. Conclusion Transvenous implantation of the LV lead is safe and achievable for CRT with high procedural success rates. For the first time we describe the late complications from CRT in different heart failure populations. This group of patients must be kept under surveillance, not only for heart failure events but also for device-related issues. The reasons for higher complication rates in DCM patients require further evaluation.

Introduction With increasing numbers and complexity of implantable devices, the need for lead extraction is also increasing. There is little UK data available on clinical outcomes. We compiled a multi-centre registry of patients undergoing lead extraction to investigate predictors of success and complications. Methods Data on all cases at three UK tertiary centres (St. Barts and The Heart Hospital London and Papworth Hospital Cambridge) were collected over 18 months. Cases where leads were >1 year in age or where specialist extraction equipment was used were included (cases=137, leads=268). Results 69% of patients were male, age 66±16 years (mean±SD). Devices extracted were single chamber PPMs (5%), dual chamber PPMs (42%), CRTPs (6%), single chamber ICDs (6%), dual chamber ICDs (17%) and CRTDs (24%). 76% of ICD leads were dual coil. Number of leads extracted per patient was 2.0±1.0 and time from implantation was 8.3±11.1 years. Leads were extracted using simple traction (39%), traction with locking stylets alone (8%) or dilator sheaths (5%), bidirectional cutting sheaths (38%) or laser (10%). Only 2% of cases required additional femoral access. Specialist equipment was preferentially used for older leads (10.4±13.1 vs 5.2±5.8 years, p The rate of major procedural adverse events (AE) leading to death or emergent surgery was 2.2%, major AEs unrelated to the procedure was 5.8% and minor AEs was 8.7%. Predictors of AEs include patient age (77±28 vs 66±15 years, p=0.05), the age but not type or number of lead (14.8±24.5 vs 7.2±6.0 years, p=0.01), systemic infectiona(31 vs 8%, p 4 cm of lead remaining in situ. Predictors of procedural failure include age but not type or number of leads (11.1±8.6 vs 8.3±11.3 years, p=0.05), systemic infectionc(24 vs 3%, p Discussion This is the first UK prospective multi-centre study of lead extraction data comparing extraction techniques. Overall there is a low major complication and high success rate with the use of either simple traction or specialist equipment. From our findings, high risk cases can be identified pre-procedure to allow adequate case planning. Laser extraction is clinically effective but is associated with a higher complication rates compared with mechanical cutting sheaths.

There is an increasing need for catheter ablation procedures to treat complex atrial tachycardias (AT) and atrial fibrillation (AF), often requiring detailed endocardial mapping. The sequential point-to-point contact mapping of complex arrhythmias is time-consuming and may not always be feasible. We assessed the utility of a novel spiral duo-decapolar high-density (HD) mapping catheter to delineate complex arrhythmia substrates for ablation.The patients underwent HD mapping using a spiral catheter (AFocusII) and the EnSite NavX system, during catheter ablation procedures, to treat atrial arrhythmias.In 26 patients, a total of 32 atrial arrhythmias were mapped and ablated, comprising of five focal AT, eight macroreentrant AT, 11 persistent AF and eight paroxysmal AF. The HD catheter was used to acquire endocardial surface geometries in all cases and to map the pulmonary veins in patients undergoing AF ablation. In persistent AF, HD catheter mapping permitted the creation of highly detailed complex fractionated electrogram maps (left atrium 449 ± 128 points in 7.2 ± 2.6 min; right atrium 411 ± 113 points in 6.7 ± 1.6 min). In AT, activation mapping was performed with the acquisition of 305 ± 158 timing points in 7.3 ± 2.6 min, guiding successful ablation in all cases. During the follow-up of 7.0 ± 2.6 months, all AT patients remained free of significant arrhythmia.High-density contact mapping with a novel spiral multipolar catheter allows rapid assessment of focal and macroreentrant AT, and complex fractionated electrical activity in the atria. It has further multi-functional capabilities as a pulmonary vein mapping catheter and for accurate geometry creation when used with a 3D mapping system.

To establish clinical factors affecting success in persistent atrial fibrillation (AF) ablation.Wide area circumferential ablation with linear and electrogram-based left atrial (LA) ablation was performed in 191 consecutive patients for persistent AF. After mean follow-up of 13.0 ± 8.9 months, overall success was 64% requiring a mean of 1.5 procedures. Single procedure success rate was 32%. Left atrial size was a univariate predictor of recurrence after a single procedure (P =0.04). Only LA size [hazard ratio (HR) 1.05/mm with 95% confidential interval (CI) 1.02-1.08] was an independent predictor of recurrence after a single procedure. Only LA size was a univariate predictor of recurrence after multiple procedures (P0.01). Left atrial size (HR 1.07/mm with 95% CI 1.02-1.11) and hypertrophic cardiomyopathy (HCM; HR 2.42 with 95% CI 1.06-5.55) were independent predictors of recurrence after multiple procedures. Ablation strategy did not affect success after a single procedure. Left atrial size of43 mm predicted long-term success with a sensitivity of 92%, specificity 52%, positive predictive value 49%, and negative predictive value 93%. With LA size43 mm, HCM (HR 3.09 with 95% CI 1.70-7.5) and AF duration (HR 1.07/year with 95% CI 1.00-1.13) were independent predictors of recurrence.Left atrial size is the major independent determinant of AF recurrence after ablation for persistent AF. This has important implications for patient selection for persistent AF ablation and the evaluation of AF ablation clinical trial results.

In an attempt to improve procedural outcomes and reduce time and complications, there has been particular interest in alternative technologies specifically designed for atrial fibrillation (AF) ablation. One novel technique is isolation of the pulmonary veins using an over-the-wire multielectrode catheter delivering duty-cycled bipolar and unipolar radiofrequency energy. Phrenic nerve injury is a rare but significant complication of AF ablation. This is the first report of phrenic nerve injury following catheter ablation for AF using the Pulmonary Vein Ablation Catheter (Medtronic, Minneapolis, MN, USA).

The rate of cardiac device implantation has risen significantly secondary to an increase in the number of indications. Wound infection and lead displacement are two common and potentially life-threatening complications. No national/international guidelines address postoperative care and controversy exists regarding wound management and arm movement following cardiac device implantation.We aimed to explore and review the evidence behind current practice but found that certain aspects of established practice.An electronic search of the databases EMBASE, British Nursing Index, CINAHL, Cochrane and PubMed to identify evidence regarding wound management and lead displacement.We found that certain aspects of established practice are based on tradition rather than evidence. Recent guidelines on wound management published by The National Institute for Health and Clinical Excellence in the UK recommend covering the wound postoperatively for 48 h with a low-adherent transparent dressing and letting patients shower thereafter. Since specific guidelines for cardiac device patients are lacking, we suggest that further research address whether or not the NICE guidelines can be extrapolated to this area. Studies showed that early mobilisation and allowing a full range of arm movements following device implantation is safe. Further research must validate these findings.We discuss the reasons behind these gaps in the evidence base and support the idea that nursing education has not placed enough emphasis on how to critically appraise research. This accounts for the very small proportion of nurses that get involved in conducting research and generating guidelines. Additionally, we argue that nurses can play a key role in identifying and addressing research questions that lead to improved patient outcome. Thus, we support proposals to enhance nurses' opportunities to pursue academic careers to achieve adequate research skills.

Aims The exact role of transoesphageal echo (TOE) prior to atrial fibrillation (AF) ablation remains unclear. This study examines the incidence and predictors of left atrial (LA) thrombus in patients undergoing AF ablation. Methods and results Patients were treated with warfarin for at least 4 weeks prior to ablation. This was substituted with therapeutic dalteparin 3 days before the procedure. All patients underwent TOE to exclude LA thrombus. Six clinical risk factors for thrombus were defined, known to be risk factors for stroke in AF: age >75, diabetes, hypertension, valve disease, prior stroke, or transient ischaemic attack and cardiomyopathy. A total of 635 procedures were performed. The incidence of thrombus was 12/635 (1.9%) despite therapeutic anti-coagulation. Patients with thrombus had larger LA diameter, mean 50.6 ± 6.2 mm vs. 44.2 ± 7.6 ( P = 0.006). In univariate analysis, persistent AF [odds ratio (OR) = 10.4 with 95% CI 1.8–19.1], hypertension [OR = 11.7 with 95% CI 2.5–54.1], age >75 (OR = 4.5 with 95% CI 1.2–17.2), and cardiomyopathy (OR 5.9 with 95% CI 1.8–19.1) were significantly associated with thrombus. In multivariate analysis, hypertension (OR = 14.2 with 95% CI 2.6–77.5), age >75 (OR = 8.1, 95% CI 1.5–44.9), and cardiomyopathy (OR = 10.5 with 95% CI 2.6–77.5) were independently associated with thrombus. There was no thrombus in patients without clinical risk factors. Conclusion In patients presenting for AF ablation, LA thrombus is only seen in those with clinical risk factors. TOE is indicated in this group but may be unnecessary in patients without clinical risk factors.

Aims An important decision in the management of patients with atrial fibrillation is whether to adopt a rate or rhythm control strategy. Options for the latter include oral membrane-active anti-arrhythmic drugs (AADs) or catheter ablation. Recent prescription trends may have been affected by the introduction of dronedarone and an increasing number of reports suggesting increased mortality in those taking AADs. We describe the trend in oral AAD prescriptions in England in the period 1998–2014. Methods and results We conducted a retrospective study using data from the Prescription Cost Analysis system, which holds information on every prescription dispensed in the community in England. We obtained data from 1998 to October 2014 for all Class Ia, Ic, and III AADs. Amiodarone and sotalol remain the most commonly prescribed AADs in England, though the use of both is decreasing. There has been a linear increase in the uptake of flecainide. Dronedarone prescriptions peaked in 2011, and our most recent data show that amiodarone prescriptions are 25-fold those of dronedarone. Conclusion There is a decline in the use of amiodarone and sotalol consistent with the growing safety concerns with these drugs along with neutral results from landmark trials comparing rate and rhythm control. Dronedarone has failed to make an impact on AAD prescribing. In contrast, flecainide has seen an increase in use during the study period. [10.1093/ehjcvp/pvv058][1] [1]: /lookup/doi/10.1093/ehjcvp/pvv058

Background— Ablation of complex fractionated atrial electrograms (CFAEs) has been proposed as a strategy to improve outcomes in atrial fibrillation (AF) catheter ablation, but the use of this technique remains contentious. We aimed to assess the impact of CFAE ablation in addition to pulmonary vein isolation (PVI) in patients undergoing ablation for AF. Methods and Results— We performed a random effects meta-analysis of studies comparing PVI versus PVI+CFAE ablation. The outcomes of freedom from AF/atrial tachycardia after 1 or several ablation procedures and acute procedural–related complications were assessed. Studies were searched on MEDLINE, EMBASE, COCHRANE, and clinicaltrials.gov , and sensitivity analyses were performed. Thirteen studies including a total of 1415 patients were considered eligible. Additional ablation of CFAEs resulted in no improvement in mid-term procedural outcome or freedom from AF or atrial tachycardia (odds ratio [OR], 0.80; 95% confidence interval [CI], 0.58–1.10; P =0.17). Sensitivity analysis of 398 paroxysmal AF ablation procedures showed no incremental benefit of CFAE ablation (OR, 0.80; 95% CI, 0.46–1.38; P =0.42). PVI+CFAE ablation versus PVI alone did not improve the overall rate of freedom from AF or atrial tachycardia in patients with persistent AF (OR, 1.01; 95% CI, 0.63–1.64; P =0.96) or longstanding persistent AF (OR, 0.84; 95% CI, 0.24–2.96; P =0.79). There was no increase in procedural-related adverse events (OR, 1.06; 95% CI, 0.41–2.75; P =0.91). Conclusions— Despite the apparent safety of this technique, CFAE ablation did not improve freedom from AF/atrial tachycardia in patients with paroxysmal or persistent AF. The role of CFAE ablation in addition to PVI should be questioned and other alternatives assessed to improve the outcome of AF ablation.

Worldwide around 7 million people suffer myocardial infarctions per year according to White et al. (2008). Around one third of these patients having acute myocardial infarction die within the first hour of having symptoms usually due to fatal arrhythmia. Characteristic ST segment elevation in the 12 lead electrocardiogram (ECG) accompanied by clinical symptoms of chest pain provide the most rapid way to diagnose those patients who should receive thrombolysis to help dissolve thrombus and restore blood flow. In fact, since the early 1980s, thombolysis has been the cornerstone of treatment for patients having ST segment elevation myocardial infarctions (STEMI) by improving outcomes and preserving left ventricular function. There are in fact many large randomised clinical trials which support early thrombolysis and these can be found in the Fibrinolytic Therapy Trialists’ (FTT) Collaborative Group publication from 1994. This document reinforces the importance of early reperfusion with 30 lives per 10000 being saved by thrombolysis given within 6 hours of presentation and 20 lives per 1000 saved if initiation is between 6 and 12 hours.

With the expansion in catheter-based treatments for atrial fibrillation the number of transseptal punctures being performed by cardiac electrophysiologists has increased significantly. Although in general transseptal puncture is successful, in a small percentage of cases it cannot be achieved due to complex intraatrial anatomy. We report the case of a difficult transseptal puncture (TSP), performed where the conventional approach using a Brockenbrough needle sheath was unable to perforate the septum. TSP was only achieved using a novel technique assisted by an angioplasty wire.

A 70-year-old man with paroxysmal atrial fibrillation was referred for pulmonary vein isolation. Past medical history included ischemic heart disease and a right hemicolectomy for Duke’s C carcinoma 10 years previously. Presenting ECG showed sinus rhythm with a normal axis and evidence of left atrial enlargement (Figure 1). Preoperative echocardiography demonstrated normal left ventricular structure and function. After routine single transseptal puncture, retrograde pulmonary venography was performed. This demonstrated 2 large right pulmonary veins and a left common pulmonary vein. Subsequently, an uncomplicated wide-area circumferential ablation …

Introduction Targeting fractionated electrograms (EGMs) is commonly used in catheter ablation (CA) of persistent atrial fibrillation (PersAF). Several automated algorithms exist to identify sites of fractionation. EGMs exhibiting continuous activity (ContA) and a high organisation index (OI) have also been proposed as features of significant sites. We investigated five indices of fractionation to assess the consistency of signal classification, and associated the effects of ablation lesions to these classification techniques. Methods 16 patients undergoing first-time CA of persAF were studied. A NavX CFAE map was acquired after circumferential pulmonary vein isolation. EGM data were exported and analysed in custom software. CA was performed on sites showing high ContA. Offline analysis compared 5 algorithms: ContA, OI, Dominant Frequency (DF), CFAEmean (NavX equivalent) and shortest complex interval (SCI, Carto equivalent) after signal screening. The effect of ablation lesions on AF cycle length was correlated with underlying fractionation. Results CA on ContA sites terminated AF in 50% cases. 2589 8-s EGMs and 471 ablation lesions targeting fractionation were analysed. Varying the refractory periods (RP) of algorithms produced large changes in signal classification for CFAEmean (Pearson R=0.81±0.05 for 10 ms variation in RP, R=0.08 for 90 ms variation in RP) and SCI (R=0.95±0.04 for 10 ms, R=−0.34 for 90 ms), whereas ContA was unaffected (R=0.99±0.01 for 10 ms, R=0.80 for 90 ms). There was a modest inverse correlation between DF and OI of EGMs (R=−0.58, p 0.5, similar for DF). Only 2±1% of EGMs were in the top quintile of fractionation by all 3 indices of CFEmean, ContA and SCI. Only high OI (ROC AUC=0.64 p Conclusions The classification of fractionated EGMs is very sensitive to user-selected characteristics. Interpretation of results of “fractionation maps” must take into account analysis techniques, OI appears the most promising at guiding appropriate ablation site.