Outcomes From Pediatric Ablation: A Review of 20 Years of National Data.

OBJECTIVES: This study set out to examine outcomes from pediatric supraventricular tachycardia ablations over a 20-year period. This study sought to examine success rates and repeat ablations over time and to evaluate whether modalities such as 3-dimensional (3D) mapping, contact force, and cryotherapy have improved outcomes. BACKGROUND: Ablation of supraventricular tachycardia in pediatric patients is commonly performed in most congenital heart centers with excellent long-term results. METHODS: Data were retrieved from the NICOR (National Institute of Clinical Outcomes Research) database in the United Kingdom. Outcomes over time were evaluated, and procedure-related details were compared. RESULTS: There were 7,069 ablations performed from January 1, 1999, to December 31, 2018, at 10 centers. Overall, ablation success rates were 92% for accessory pathways, 97% for atrioventricular node re-entry tachycardia, and 89% for atrial tachycardia. There was an improvement in procedural success rates over time (p < 0.01). The use of 3D mapping did not alter success or need for repeat ablation but was associated with a higher proportion of lower fluoroscopy cases; 55% of 3D mapping cases used <5 min of fluoroscopy (p < 0.01). Patients needing a repeat ablation were 341 (12%) for accessory pathways, 128 (7%) for atrioventricular node re-entry tachycardia, and 35 (7%) for atrial tachycardia. Overall, the risk of complete heart block was low (n = 12, <0.01%). The use of cryotherapy was associated with an increased risk of needing a repeat ablation. CONCLUSIONS: Overall success rates from pediatric ablations are excellent and compare favorably to other registries. Introduction of newer technologies have likely made procedures safer and reduced radiation exposure, but they have not changed success rates or the need for a repeat procedure.

Diagnostic Impact of Repeated Expert Review & Long-Term Follow-Up in Determining Etiology of Idiopathic Cardiac Arrest.

Background Recognizing the etiology of sudden cardiac arrest (SCA) has an enormous impact on the management of victims and their immediate families. A significant proportion of SCA survivors with a structurally normal heart are not offered a diagnosis and there is no clear consensus on the type and duration of follow-up. We aimed to assess the utility of a multidisciplinary approach in optimizing diagnosis of cardiac arrest etiology during follow-up. Methods and Results We retrospectively assessed 327 consecutive SCA survivors (mean age 61.9±16.2 years, 80% men) who underwent secondary prevention implantable cardioverter defibrillators between May 2015 and November 2018. The initial diagnosis was recorded at the time of admission and follow-up diagnosis was deduced from subsequent clinic records, investigations, and outcomes of multidisciplinary team meetings. Structural heart disease accounted for 282 (86%) of SCAs. Forty-five (14%) patients had a structurally normal heart and underwent comprehensive testing and follow-up (mean duration 93±52 weeks). On initial evaluation, 14/45 (31%) of these received a diagnosis, rising to 29/45 (64%) with serial reviews during follow-up. Discussion in multidisciplinary team meetings and imaging reassessment accounted for 47% of new diagnoses. No additional diagnoses were made beyond 96 weeks. Nineteen (5.8%) fatalities occurred in the entire cohort, exclusively in patients with structural heart disease. Conclusions Systematic comprehensive testing combined with multidisciplinary expert team review of SCA survivors without structural heart disease improves the yield and time to diagnosis compared with previously published studies. This approach has positive implications in the management of SCA survivors and their families.

A Primary Prevention Clinical Risk Score Model for Patients With Brugada Syndrome (BRUGADA-RISK).

OBJECTIVES: The goal of this study was to develop a risk score model for patients with Brugada syndrome (BrS). BACKGROUND: Risk stratification in BrS is a significant challenge due to the low event rates and conflicting evidence. METHODS: A multicenter international cohort of patients with BrS and no previous cardiac arrest was used to evaluate the role of 16 proposed clinical or electrocardiogram (ECG) markers in predicting ventricular arrhythmias (VAs)/sudden cardiac death (SCD) during follow-up. Predictive markers were incorporated into a risk score model, and this model was validated by using out-of-sample cross-validation. RESULTS: A total of 1,110 patients with BrS from 16 centers in 8 countries were included (mean age 51.8 ± 13.6 years; 71.8% male). Median follow-up was 5.33 years; 114 patients had VA/SCD (10.3%) with an annual event rate of 1.5%. Of the 16 proposed risk factors, probable arrhythmia-related syncope (hazard ratio [HR]: 3.71; p < 0.001), spontaneous type 1 ECG (HR: 3.80; p < 0.001), early repolarization (HR: 3.42; p < 0.001), and a type 1 Brugada ECG pattern in peripheral leads (HR: 2.33; p < 0.001) were associated with a higher risk of VA/SCD. A risk score model incorporating these factors revealed a sensitivity of 71.2% (95% confidence interval: 61.5% to 84.6%) and a specificity of 80.2% (95% confidence interval: 75.7% to 82.3%) in predicting VA/SCD at 5 years. Calibration plots showed a mean prediction error of 1.2%. The model was effectively validated by using out-of-sample cross-validation according to country. CONCLUSIONS: This multicenter study identified 4 risk factors for VA/SCD in a primary prevention BrS population. A risk score model was generated to quantify risk of VA/SCD in BrS and inform implantable cardioverter-defibrillator prescription.

Trends in implantable cardioverter defibrillator and cardiac resynchronisation therapy lead parameters for patients with arrhythmogenic and dilated cardiomyopathies.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) lead parameters may deteriorate due to right ventricular (RV) disease such as arrhythmogenic right ventricular cardiomyopathy (ARVC), with implications for safe delivery of therapies. We compared ICD and CRT-D (cardiac resynchronisation therapy-defibrillator) lead parameters in patients with ARVC and dilated cardiomyopathy (DCM). METHODS: RV lead sensing (R wave amplitude) and pacing (threshold and amplitude-pulse width product (APWP)), left ventricular (LV) pacing (APWP), and imaging parameter trends were assessed in 18 patients with ARVC and 18 with DCM. RESULTS: R wave amplitude did not change significantly over time in either group (over 5 years, ARVC -0.4 mV, 95% CI -3.8-3.0 mV; DCM -1.8 mV, 95% CI -5.0-1.3 mV). Within ARVC group, divergent trends were seen according to lead position. DCM patients experienced an increase in RV lead threshold (+1.1 V over 5 years, 95% CI + 0.5 to +1.7 V) and RV APWP (+0.48 Vms over 5 years, 95% CI + 0.24 to +0.71 Vms); ARVC patients had no change. ARVC patients had a higher LVEF at baseline than DCM patients (52 vs 20%, p < 0.001), though LVEF decreased over time for the former, while increasing for the latter. TAPSE did not change over time for ARVC patients. CONCLUSIONS: Lead parameters in ARVC patients were stable over medium-term follow up. In DCM patients, RV lead threshold and RV and LV APWP increased over time. These differential responses for DCM and ARVC were not explained by imaging indices, and may reflect distinct patterns of disease progression.

Prolonged action potential duration and dynamic transmural action potential duration heterogeneity underlie vulnerability to ventricular tachycardia in patients undergoing ventricular tachycardia ablation.

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 <0.5 mV was defined as dense scar, 0.5-1.5 mV as scar borderzone, and >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 < 0.001). Endocardial APD was 210 ms in normal tissue vs. 222 ms in the scar borderzone and 238 ms in dense scar (P < 0.01). This resulted in significant transmural RT dispersion (ΔRT 22 ms across dense transmural scar vs. 5 ms in normal transmural tissue, P < 0.001), dependent on the scar characteristics in the Endo and Epi, and the pacing site. CONCLUSION: Areas of myocardial scar have prolonged APD compared with normal tissue. Heterogeneity of regional transmural and planar APD result in localized dispersion of repolarization, which may play an important role in initiating VT.

Medium-term outcomes of idiopathic ventricular fibrillation survivors and family screening: a multicentre experience.

AIMS: Early repolarization (ER) has been linked to poorer outcomes in idiopathic ventricular fibrillation (IVF). The role of family screening in IVF is not clear. Our aim was to review predictors for poorer outcomes and evaluate the role of family screening in IVF. METHODS AND RESULTS: This was a retrospective multicentre cohort study including all patients diagnosed with IVF. Data were collected on baseline characteristics, ECG findings, and recurrence of ventricular arrhythmia (VA) during follow-up. Electrocardiogram findings were reviewed in first-degree relatives that were screened. A total of 66 patients were included with male predominance (42/66, 64%) and Caucasian ethnicity (47/66, 71%). Mean age at cardiac arrest was 38 years ± 11. Thirty-one patients had ER (47%) predominantly with J-point amplitude ≥2 mm and horizontal ST segments (18/31, 58%). Recurrent VA was seen in 13 patients (20%). Horizontal ST segments were associated with increased rates of VA recurrence (OR 11, 95% CI 2.7-43.7; P = 0.0007). Early repolarization was seen in 20% of the 72 first-degree relatives and was more common if the proband had persistent ER pattern (OR 10.7, 95% CI 2.2-51.5; P = 0.003). CONCLUSION: Ventricular arrhythmia recurrence was lower than previously reported. Early repolarization was common in this IVF cohort, and horizontal ST segments were suggestive predictor for poorer outcomes. Persistent ER in proband was associated with ER in first-degree relatives. With better understanding of its predictive value and the relationship to IVF, this information could potentially be used to guide family screening and identify new mutations using family members with persistent ER.

Radiofrequency ablation of atrial tachyarrhythmias in adults with tetralogy of Fallot - predictors of success and outcome.

BACKGROUND: Adults with tetralogy of Fallot experience atrial tachyarrhythmias; however, there are a few data on the outcomes of radiofrequency ablation. We examined the characteristics, outcome, and predictors of recurrence of atrial tachyarrhythmias after radiofrequency ablation in tetralogy of Fallot patients. Methods/results Retrospective data were collected from 2004 to 2013. In total, 56 ablations were performed on 37 patients. We identified two matched controls per case: patients with tetralogy of Fallot but no radiofrequency ablation and not known to have atrial tachyarrhythmias. Acute success was 98%. Left atrial arrhythmias increased in frequency over time. The mean follow-up was 41 months; 78% were arrhythmia-free. Number of cardiac surgeries, age, and presence of atrial fibrillation were predictors of recurrence. Lone cavo-tricuspid isthmus-dependent flutter reduced the likelihood of atrial fibrillation. Right and left atria in patients with tetralogy of Fallot were larger in ablated cases than controls. NYHA class was worse in cases and improved after ablation; baseline status predicted death. Of matched non-ablated controls, a number of them had atrial fibrillation. These patients were excluded from the case-control study but analysed separately. Most of them had died during follow-up, whereas of the matched ablated cases all were alive and the majority in sinus rhythm. CONCLUSION: Patients with tetralogy of Fallot and atrial tachyarrhythmias have more dilated atria than those without atrial tachyarrhythmias. Radiofrequency ablation improves functional status. Left atrial ablation is more commonly required with repeat procedures. There is a high prevalence of atrial tachyarrhythmias, particularly atrial fibrillation, in patients with tetralogy of Fallot; early radiofrequency ablation may have a protective effect against this.

Ventricular stimulus site influences dynamic dispersion of repolarization in the intact human heart.

The spatial variation in restitution properties in relation to varying stimulus site is poorly defined. This study aimed to investigate the effect of varying stimulus site on apicobasal and transmural activation time (AT), action potential duration (APD) and repolarization time (RT) during restitution studies in the intact human heart. Ten patients with structurally normal hearts, undergoing clinical electrophysiology studies, were enrolled. Decapolar catheters were placed apex to base in the endocardial right ventricle (RVendo) and left ventricle (LVendo), and an LV branch of the coronary sinus (LVepi) for transmural recording. S1-S2 restitution protocols were performed pacing RVendo apex, LVendo base, and LVepi base. Overall, 725 restitution curves were analyzed, 74% of slopes had a maximum slope of activation recovery interval (ARI) restitution (Smax) > 1 (P < 0.001); mean Smax = 1.76. APD was shorter in the LVepi compared with LVendo, regardless of pacing site (30-ms difference during RVendo pacing, 25-ms during LVendo, and 48-ms during LVepi; 50th quantile, P < 0.01). Basal LVepi pacing resulted in a significant transmural gradient of RT (77 ms, 50th quantile: P < 0.01), due to loss of negative transmural AT-APD coupling (mean slope 0.63 ± 0.3). No significant transmural gradient in RT was demonstrated during endocardial RV or LV pacing, with preserved negative transmural AT-APD coupling (mean slope -1.36 ± 1.9 and -0.71 ± 0.4, respectively). Steep ARI restitution slopes predominate in the normal ventricle and dynamic ARI; RT gradients exist that are modulated by the site of activation. Epicardial stimulation to initiate ventricular activation promotes significant transmural gradients of repolarization that could be proarrhythmic.

Diagnostic yield of molecular autopsy in patients with sudden arrhythmic death syndrome using targeted exome sequencing.

AIMS: The targeted genetic screening of Sudden Arrhythmic Death Syndrome (SADS) probands in a molecular autopsy has a diagnostic yield of up to 35%. Exome sequencing has the potential to improve this yield. The primary aim of this study is to examine the feasibility and diagnostic utility of targeted exome screening in SADS victims, utilizing familial clinical screening whenever possible. METHODS AND RESULTS: To determine the feasibility and diagnostic yield of targeted exome sequencing deoxyribonucleic acid (DNA) was isolated from 59 SADS victims (mean age 25 years, range 1-51 years). Targeted exome sequencing of 135 genes associated with cardiomyopathies and ion channelopathies was performed on the Illumina HiSeq2000 platform. Non-synonymous, loss-of-function, and splice-site variants with a minor allele frequency <0.02% in the NHLBI exome sequencing project and an internal set of control exomes were prioritized for analysis followed by <0.5% frequency threshold secondary analysis. First-degree relatives were offered clinical screening for inherited cardiac conditions. Seven probands (12%) carried very rare (<0.02%) or novel non-sense candidate mutations and 10 probands (17%) had previously published rare (0.02-0.5%) candidate mutations-a total yield of 29%. Co-segregation fully confirmed two private SCN5A Na channel mutations. Variants of unknown significance were detected in a further 34% of probands. CONCLUSION: Molecular autopsy using targeted exome sequencing has a relatively low diagnostic yield of very rare potentially disease causing mutations. Candidate pathogenic variants with a higher frequency in control populations are relatively common and should be interpreted with caution.

Safe use of MRI in people with cardiac implantable electronic devices.

MR scanning in patients with cardiac implantable electronic devices (CIEDs) was formerly felt to be contraindicated, but an increasing number of patients have an implanted MR conditional device, allowing them to safely undergo MR scanning, provided the manufacturer's guidance is adhered to. In addition, some patients with non-MR conditional devices may undergo MR scanning if no other imaging modality is deemed suitable and there is a clear clinical indication for scanning which outweighs the potential risk. The following guidance has been formulated by the British Heart Rhythm Society and endorsed by the British Cardiovascular Society and others. It describes protocols that should be followed for patients with CIEDs undergoing MR scanning. The recommendations, principles and conclusions are supported by the Royal College of Radiologists.

A systematic review of ICD complications in randomised controlled trials versus registries: is our 'real-world' data an underestimation?

Implantable cardioverter defibrillator (ICD) implantation carries a significant risk of complications, however published estimates appear inconsistent. We aimed to present a contemporary systematic review using meta-analysis methods of ICD complications in randomised controlled trials (RCTs) and compare it to recent data from the largest international ICD registry, the US National Cardiovascular Data Registry (NCDR). PubMed was searched for any RCTs involving ICD implantation published 1999-2013; 18 were identified for analysis including 6433 patients, mean follow-up 3 months-5.6 years. Exclusion criteria were studies of children, hypertrophic cardiomyopathy, congenital heart disease, resynchronisation therapy and generator changes. Total pooled complication rate from the RCTs (excluding inappropriate shocks) was 9.1%, including displacement 3.1%, pneumothorax 1.1% and haematoma 1.2%. Infection rate was 1.5%.There were no predictors of complications but longer follow-up showed a trend to higher complication rates (p=0.07). In contrast, data from the NCDR ICD, reporting on 356 515 implants (2006-2010) showed a statistically significant threefold lower total major complication rate of 3.08% with lead displacement 1.02%, haematoma 0.86% and pneumothorax 0.44%. The overall ICD complication rate in our meta-analysis is 9.1% over 16 months. The ICD complication reported in the NCDR ICD registry is significantly lower despite a similar population. This may reflect under-reporting of complications in registries. Reporting of ICD complications in RCTs and registries is very variable and there is a need to standardise classification of complications internationally.

Is CRT pro-arrhythmic? A comparative analysis of the occurrence of ventricular arrhythmias between patients implanted with CRTs and ICDs.

UNLABELLED: Aim and Hypothesis: Despite the proven symptomatic and mortality benefit of cardiac resynchronization therapy (CRT), there is anecdotal evidence it may be pro-arrhythmic in some patients. We aimed to identify if there were significant differences in the incidence of ventricular arrhythmias (VAs) in patients undergoing CRT-D and implantable cardioverter-defibrillators (ICD) implantation for primary prevention indication. We hypothesized that CRT is unlikely to be pro-arrhythmic based on the positive mortality and morbidity data from large randomized trials. METHODS AND RESULTS: A retrospective analysis of device therapies for VA in a primary prevention device cohort was performed. Patients with ischemic (IHD) and non-ischemic (DCM) cardiomyopathy and ICD or CRT+ICD devices (CRT-D) implanted between 2005 and 2007 without prior history of sustained VA were included for analysis. VA episodes were identified from stored electrograms and defined as sustained (VT/VF) if therapy [anti-tachycardia pacing (ATP) or shocks] was delivered or non-sustained (NSVT) if not. Of a total of 180 patients, 117 (68% male) were in the CRT-D group, 42% IHD, ejection fraction (EF) 24.5 ± 8.2% and mean follow-up 23.9 ± 9.8 months. 63 patients (84% male) were in the ICD group, 60% IHD, EF 27.7 ± 7.2% and mean follow-up 24.6 ± 10.8 months. Overall, there was no significant difference in the incidence of VA (35.0 vs. 38.1%, p = 0.74), sustained VT (21.3 vs. 28.5%, p = 0.36) or NSVT (12.8 vs. 9.5%, p = 0.63) and no significant difference in type of therapy received for VT/VF: ATP (68 vs. 66.6%, p = 0.73) and shocks (32 vs. 33.3%, p = 0.71) between the CRT-D and ICD groups, respectively. CONCLUSION: In patients with cardiomyopathy receiving CRT-D and ICDs for primary prophylaxis, there was no significant difference in the incidence of VA. From this single center retrospective analysis, there is no evidence to support cardiac resynchronization causing pro-arrhythmia.

Dynamic conduction and repolarisation changes in early arrhythmogenic right ventricular cardiomyopathy versus benign outflow tract ectopy demonstrated by high density mapping & paced surface ECG analysis.

AIMS: The concealed phase of arrhythmogenic right ventricular cardiomyopathy (ARVC) may initially manifest electrophysiologically. No studies have examined dynamic conduction/repolarization kinetics to distinguish benign right ventricular outflow tract ectopy (RVOT ectopy) from ARVC's early phase. We investigated dynamic endocardial electrophysiological changes that differentiate early ARVC disease expression from RVOT ectopy. METHODS: 22 ARVC (12 definite based upon family history and mutation carrier status, 10 probable) patients without right ventricular structural anomalies underwent high-density non-contact mapping of the right ventricle. These were compared to data from 14 RVOT ectopy and 12 patients with supraventricular tachycardias and normal hearts. Endocardial & surface ECG conduction and repolarization parameters were assessed during a standard S1-S2 restitution protocol. RESULTS: Definite ARVC without RV structural disease could not be clearly distinguished from RVOT ectopy during sinus rhythm or during steady state pacing. Delay in Activation Times at coupling intervals just above the ventricular effective refractory period (VERP) increased in definite ARVC (43 ± 20 ms) more than RVOT ectopy patients (36 ± 14 ms, p = 0.03) or Normals (25 ± 16 ms, p = 0.008) and a progressive separation of the repolarisation time curves between groups existed. Repolarization time increases in the RVOT were also greatest in ARVC (definite ARVC: 18 ± 20 ms; RVOT ectopy: 5 ± 14, Normal: 1 ± 18, p<0.05). Surface ECG correlates of these intracardiac measurements demonstrated an increase of greater than 48 ms in stimulus to surface ECG J-point pre-ERP versus steady state, with an 88% specificity and 68% sensitivity in distinguishing definite ARVC from the other groups. This technique could not distinguish patients with genetic predisposition to ARVC only (probable ARVC) from controls. CONCLUSIONS: Significant changes in dynamic conduction and repolarization are apparent in early ARVC before detectable RV structural abnormalities, and were present to a lesser degree in probable ARVC patients. Investigation of dynamic electrophysiological parameters may be useful to identify concealed ARVC in patients without disease pedigrees by using endocardial electrogram or paced ECG parameters.

A simple infection-control protocol to reduce serious cardiac device infections.

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.

An 8-year single-centre experience of cardiac resynchronisation therapy: procedural success, early and late complications, and left ventricular lead performance.

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) and late (>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.

Catheter ablation of atrial fibrillation-patient satisfaction from a single-center UK experience.

BACKGROUND: Patient satisfaction is an indicator of quality of care and a key factor for patients' healthcare choices. Although atrial fibrillation (AF) ablation is now common, there are no published data on patient satisfaction during this procedure. METHODS: Anonymous patient satisfaction questionnaires were distributed to consecutive AF ablation patients over 6 months at a single center. RESULTS: Of 101 questionnaires returned, 51 % related to a first procedure. Pre-operative clinic experiences were good. Prior to ablation, 53 % reported receiving information leaflets, while 55 % reported using the Internet to search for further information. Mean anxiety pre-procedurally on a ten-point scale was 3.1 ± 2.9 and 97 % of patients felt prepared. Afterwards, however, 31 % found the experience not as expected, mainly due to being in more pain or more awake. A large number of patients recalled the procedure in detail, despite use of conscious sedation. Overall cath lab experience was good or excellent for the majority (79 %). Patients felt less well than expected immediately post-procedure and perceived a higher complication rate immediately after ablation (24 %) and at home (32 %) than reported by physicians (4.5 %). Despite this, 89 % would recommend an AF ablation to a friend or relative, and 96 % would recommend our institution. CONCLUSION: Our findings suggest that most patients are satisfied with the AF ablation experience, but this is not solely dependent on procedural success. Dissatisfaction occurs due to unmet expectations, particularly excess pain, i.e. greater than expected, during and after ablation. An improved consent process may improve patient experience. Physicians should also address initiatives to reduce pain during AF ablation.

A randomized double-blind crossover trial of triventricular versus biventricular pacing in heart failure.

AIMS: A significant proportion of patients implanted with biventricular (BiV) devices fail to respond. Clinical response may be improved by additional ventricular stimulation sites. This single-centre, double-blinded randomized crossover trial aimed to determine whether long-term multisite ventricular pacing is superior to conventional BiV pacing in heart failure patients. METHODS AND RESULTS: A total of 43 patients referred for cardiac resynchronization therapy (CRT) underwent transvenous implantation of a triventricular (TriV) device. Pacing leads were positioned in the right ventricular (RV) apex and a lateral coronary sinus (CS) branch, with a third ventricular lead implanted in a further lateral CS branch in 23 patients (group A) and on the high RV septum in 20 patients (group B). Devices were programmed in a randomized order to four pre-determined pacing configurations: conventional BiV, TriV, and dual-site and single-site left bentricular (LV) or RV pacing for 3-month periods with clinical and echo assessment at the end of each period. The primary endpoint was the comparison of 6 min walk distance (6MW) after 3 months of BiV vs. TriV pacing; secondary endpoints were Minnesota Living With Heart Failure (MLWHF) scores, and LV dimensions and function. The 12-month follow-up period was completed by 37 patients. Compared with BiV pacing, TriV pacing resulted in significant improvements in 6MW (451 ± 112 m vs. 425 ± 119 m, P = 0.008), MLWHF (32 ± 19 vs. 38 ± 24, P = 0.036), LV end-systolic volume (158 ± 79mL vs. 168 ± 76 mL, P < 0.05), and ejection fraction (30 ± 8% vs. 27 ± 8%, P < 0.05). CONCLUSIONS: TriV pacing was associated with significant improvements in clinical and echocardiographic parameters compared with BiV pacing.

The use of a novel nitinol guidewire to facilitate transseptal puncture and left atrial catheterization for catheter ablation procedures.

AIMS: An increasing number of transseptal punctures (TSPs) are performed worldwide for atrial ablations. Transseptal punctures can be complex and can be associated with potentially life threatening complications. The purpose of the study was to evaluate the safety and efficacy of a novel transseptal guidewire (TSGW) designed to facilitate TSPs. METHODS AND RESULTS: Transseptal punctures were performed using a SafeSept TSGW passed through a standard TSP apparatus. Transseptal punctures were performed by standard technique with additional use of a TSGW allowing probing of the interatrial septum without needle exposure and penetration of the fossa into the left atrium (LA). Transseptal puncture using the TSGW was performed in 210 patients. Left atrial access was achieved successfully in 205 of 210 patients (97.6%) and in 96.3% of patients undergoing repeat TSP. Left atrial access was achieved with the first pass in 81.2% (mean 1.4 ± 0.9 passes, range 1-6) using the TSGW. No serious complications were attributable to the use of the TSGW, even in cases of failed TSP. CONCLUSIONS: The TSGW is associated with a high success rate for TSP and may be a useful alternative to transoesophageal or intracardiac echocardiogram-guided TSP.

Prevalence of J-point elevation in sudden arrhythmic death syndrome families.

OBJECTIVES: The purpose of this study was to assess the prevalence of J-point elevation among the relatives of sudden arrhythmic death syndrome (SADS) probands. BACKGROUND: J-point elevation is now known to be associated with idiopathic ventricular fibrillation. We hypothesized that this early repolarization phenomenon is an inherited trait responsible for a proportion of otherwise unexplained SADS cases. METHODS: Families of SADS probands were evaluated in an inherited arrhythmia clinic. Twelve-lead electrocardiograms were analyzed for J-point elevation defined as >0.1 mV from baseline present in 2 or more of the inferior (II, III, and aVF) or lateral (1, aVL, V(4) to V(6)) leads. Electrocardiographic data were compared with those of 359 controls of a similar age, sex, and ethnic distribution. RESULTS: A total of 363 first-degree relatives from 144 families were evaluated. J-point elevation in the inferolateral leads was present in 23% of relatives and 11% of control subjects (odds ratio: 2.54, 95% confidence interval: 1.66 to 3.90; p < 0.001). CONCLUSIONS: J-point elevation is more prevalent in the relatives of SADS probands than in controls. This indicates that early repolarization is an important potentially inheritable pro-arrhythmic trait or marker of pro-arrhythmia in SADS.

Predictors of recurrence following radiofrequency ablation for persistent atrial fibrillation.

AIMS: To establish clinical factors affecting success in persistent atrial fibrillation (AF) ablation. METHODS AND RESULTS: 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 (P < 0.01). 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 of <43 mm predicted long-term success with a sensitivity of 92%, specificity 52%, positive predictive value 49%, and negative predictive value 93%. With LA size >43 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. CONCLUSION: 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.