Transcatheter Ablation Research Articles

European prospective multicentre study of hybrid thoracoscopic and transcatheter ablation of persistent atrial fibrillation: the HISTORIC-AF trial.

The HISTORIC-AF trial is a prospective, multicentre, single-arm study designed to evaluate the outcomes of a staged endoscopic and transcatheter ablation in patients with stand-alone, persistent or long-standing persistent atrial fibrillation (AF). From 2012 to 2015, 100 consecutive patients were enrolled and underwent thoracoscopic left atrial epicardial isolation ('box lesion') followed by transcatheter ablation in case of AF recurrency. The safety end point was the composite outcome of freedom from major adverse events at 30-days, while efficacy end points were: (i) primary: freedom from AF and stable sinus rhythm following isolated thoracospic ablation >60% and (ii) secondary: freedom from AF and stable sinus rhythm >80% following hybrid ablation (as per HRS criteria). No death occurred and surgical thoracoscopic procedure was successfully completed in all patients. Survival free from major adverse events at 30 days was 94%: there were 3 permanent pacemaker implants, 2 episodes of stroke and 1 revision for bleeding. At discharge, 87% of patients were in sinus rhythm. A staged transcatheter ablation was carried out in all patients with AF recurrences at the end of 3 months blanking period (17% of patients). At 12-months follow-up, a stable restoration of sinus rhythm was achieved in 75% and 88% of patients following isolated thoracoscopic ablation and hybrid ablation, respectively. The HISTORIC-AF trial showed that thoracoscopic isolated surgical ablation reached both the safety and the efficacy end points. Hybrid ablation steadily improved rhythm outcomes and may be considered in the future as the treatment of choice for patients with persistent and long-standing persistent AF. NCT01622907.

Frontiers in non-invasive cardiac mapping: future implications for arrhythmia treatment.

Electrocardiographic mapping (ECM) is a noninvasive technique using body surface potentials and CT geometry to reconstruct epicardial maps. ECM is emerging as an important tool not only for diagnostic mapping, but also as a guide for trans-catheter ablation of complex arrhythmias such as atrial fibrillation. It provides the clinician with an immediate global view of the substrate, allowing easier pre-procedural planning, potentially improving clinical outcomes. Panoramic mapping of ventricular fibrillation (VF) is helping to develop a better understanding of its physiology, with future implications for the identification of therapeutic targets in patients with structural heart disease, as well as in idiopathic VF.

Anatomic relationship between left coronary artery and left atrium in patients undergoing atrial fibrillation ablation.

Atrial fibrillation transcatheter ablation (TCA) is, within available atrial fibrillation rhythm control strategies, one of the most effective. To potentially improve ablation outcome in case of recurrent atrial fibrillation after a first procedure or in presence of structural myocardial disease, isolation of the pulmonary veins may be associated with extensive lesions within the left atrium. To avoid rare, but potentially life-threatening, complications, thorough knowledge and assessment of left atrium anatomy and its relation to structures in close proximity are, therefore, mandatory. Aim of the present study is to describe, by cardiac computed tomography, the anatomic relationship between aortic root, left coronary artery and left atrium in patients undergoing atrial fibrillation TCA. The cardiac computed tomography scan of 21 patients affected by atrial fibrillation was elaborated to segment left atrium, aortic root and left coronary artery from the surrounding structures and the following distances measured: left atrium and aortic root; left atrium roof and aortic root; left main coronary artery and left atrium; circumflex artery and left atrium appendage; and circumflex artery and mitral valve annulus. Above all, the median distance between left atrium and aortic root (1.9, 1.5-2.1 mm), and between circumflex artery and left atrium appendage ostium (3.0, 2.1-3.4 mm) were minimal (≤3 mm). None of measured distances significantly varied between patients presenting paroxysmal versus persistent atrial fibrillation. The anatomic relationship between left atrium and coronary arteries is extremely relevant when performing atrial fibrillation TCA by extensive lesions. Therefore, at least in the latter case, preablation imaging should be recommended to avoid rare, but potentially life-threatening, complications with the aim of an as well tolerated as possible procedure.

Left atrial appendage thrombi relate to easily accessible clinical parameters in patients undergoing atrial fibrillation transcatheter ablation: A multicenter study

BackgroundTransesophageal echocardiography (TEE) is routinely performed before atrial fibrillation (AF) transcatheter ablation to exclude the presence of left atrial (LA) or LA appendage (LAA) thrombi. The aim of the study is to evaluate if easily accessible clinical parameters may relate to the presence of LA or LAA thrombi to identify patients who could potentially avoid TEE. Methods and resultsBetween January 2012 and September 2014, data from 1539 consecutive patients undergoing TEE, as a work-up before AF transcatheter ablation, in six large volume centers were collected. Baseline clinical features, CHA2DS2-VASc score, transthoracic echocardiography and presence of thrombi at TEE were recorded. Exclusion criteria were valvular, hypertrophic or dilated cardiomyopathy, previous heart surgery or an ejection fraction ≤35%. Mean age was 59.6±10.4years, 1215 (78.9%) were males; 951 (62.9%) presented in sinus rhythm (SR) on admission, 324 (21.1%) had undergone at least one previous ablation and 900 (58.5%) had CHA2DS2-VASc score 0–1. Thrombi were encountered in 12 patients (0.8%). SR at TEE independently related to the absence of thrombi (OR 5.15, 95% CI 1.38–19.02, p=0.015); in addition to this, no patient with a CHA2DS2-VASc score 0–1 and SR on admission presented thrombi at TEE (specificity 100%, p=0.011). ConclusionIn a selected population of patients referred for AF ablation, LA/LAA thrombi prevalence is low. No patients in SR with CHA2DS2-VASc score 0–1 presented LAA thrombi at TEE, identifying a significant subset of patients who could potentially safely be spared from pre-procedural TEE.

PP-152 [AJC » Transcatheter ablation for tachyarrhythmias - Supraventricular tachycardia] Successful Radiofrequency Ablation Of Focal Atrial Tachycardia Arising From The Superior Mitral Annulus

PP-152 [AJC » Transcatheter ablation for tachyarrhythmias - Supraventricular tachycardia] Successful Radiofrequency Ablation Of Focal Atrial Tachycardia Arising From The Superior Mitral Annulus

OP-079 [AJC » Transcatheter ablation for tachyarrhythmias - Supraventricular tachycardia] A Successful Ablation of Recurrent Atrial Flutter in a Patient with Coronary Bypass Surgery by Using Three Dimensional Electroanatomic Activation Mapping

OP-079 [AJC » Transcatheter ablation for tachyarrhythmias - Supraventricular tachycardia] A Successful Ablation of Recurrent Atrial Flutter in a Patient with Coronary Bypass Surgery by Using Three Dimensional Electroanatomic Activation Mapping

PP-001 [AJC » Transcatheter ablation for tachyarrhythmias - Supraventricular tachycardia] Radiofrequency Catheter Ablation Duration is Increased In AVNRT (AV nodal reentrant tachycardia) Patients With Increased Epicardial Adipose Tissue Thickness

To assess radiofrequency (RF) catheter ablation duration among patient with increased epicardial adipose tissue thickness.

P-002 [AJC » Transcatheter ablation for tachyarrhythmias - Supraventricular tachycardia] Safety and Efficacy of Radiofrequency Catheter Ablation in Elderly

P-002 [AJC » Transcatheter ablation for tachyarrhythmias - Supraventricular tachycardia] Safety and Efficacy of Radiofrequency Catheter Ablation in Elderly

PP-137 [AJC » Transcatheter ablation for tachyarrhythmias - Atrial fibrillation] Freezing the Superior Vena Cava Potentials during Isolation of Pulmonary Veins with a Second-Generation Cryoballoon

PP-137 [AJC » Transcatheter ablation for tachyarrhythmias - Atrial fibrillation] Freezing the Superior Vena Cava Potentials during Isolation of Pulmonary Veins with a Second-Generation Cryoballoon

Very long-term outcome following transcatheter ablation of atrial fibrillation. Are results maintained after 10 years of follow up?

Atrial fibrillation (AF) transcatheter ablation is a safe and effective procedure. However, outcome over 10 years of follow-up has never been reported. The aim of this study is to assess outcome, describe predictors of recurrences, and report on quality of life (QoL) the decade after an AF ablation. Patients referred for AF ablation in a single high volume centre from June 2004 to June 2006 were enrolled and followed in a prospective fashion by yearly clinical assessment and Holter monitoring. Among 255 patients (42.7% paroxysmal AF, 77% males, after a follow-up of 125 ± 7 months), 132 (52%) were arrhythmia-free including (58, 32% after a single procedure) while 27 (10%) progressed to permanent AF. At multivariate analysis, a greater left atrium antero-posterior diameter (HR 1.05 95% CI 1.02-1.09, P = 0.02) related to arrhythmic recurrences, while no increase in blood pressure (HR 0.06 95% CI 0.02-0.20, P = 0.01), BMI (HR 0.06 95% CI 0.02-0.09, P < 0.001), and fasting glucose (HR 0.58 95% CI 0.36-0.92, P = 0.02) during follow-up were protective for arrhythmic recurrences. Overall QoL improved significantly, significantly related to the absence of recurrences, arrhythmic burden reduction and blood pressure, and BMI control (P < 0.001). The outcome of AF ablation over more than 10 years is characterized by a low incidence of progression towards permanent AF. Greater LA anteroposterior diameter related to arrhythmic recurrences, while blood pressure, BMI, and fasting blood glucose control emerged as predictors of sinus rhythm maintenance. Eventually, QoL improved significantly over the follow-up.

Junctional Ectopic Tachycardia Localization and Procedural Approach using Cryoablation.

Idiopathic junctional ectopic tachycardia (JET) may still be difficult to control with antiarrhythmic therapy. Transcatheter ablation can be challenging and may be associated with a high risk of unintended atrioventricular block. The objective of this manuscript is to report the procedural technique, the location of the successful ablation, and the procedural characteristics while utilizing 3D mapping for cryoablation of JET. A retrospective analysis was performed on all patients who had undergone cryothermal ablation for the treatment of JET at a single center. Patient, arrhythmia, and procedural information and long-term outcomes were evaluated. Thirteen patients with JET were treated by cryothermal ablation. The JET arrhythmia burden varied greatly, generally with inadequate control on medications. Left ventricular dilation was present in three patients, and one patient had dilated cardiomyopathy. The median age at the time of procedure was 13 years, with median weight of 54.1 kg. The ectopic focus was ablated in 11/13 patients within the lower 2/3 of the triangle of Koch (TOK) with cryotherapy. Ablations, which were not successful, low in the TOK were associated with substantially longer procedures, and had a higher risk of recurrence. There was late resolution of the arrhythmia in two of three acutely unsuccessful ablations. There were no complications. In the majority of patients JET can be safely ablated with the use of cryotherapy. Foci not identified in the lower 2/3 of the TOK are associated with longer procedures, more lesions, and decreased chance for long-term success.

Special electrophysiological characteristics of pediatric idiopathic ventricular tachycardia

BackgroundIdiopathic ventricular tachycardia (VT) is an important pediatric arrhythmia but relevant studies in Asian cohort are rare. We determined the electrophysiological characteristics and outcomes of this rhythm disturbance. MethodsFrom an institutional database, patients aged <18years without structural heart disease who have sustained monomorphic VT (longer than 30s) during 1995–2016 were enrolled. ResultsWe enrolled 57 idiopathic VT patients (male:female=31:26). The initial presentation included palpitation (64.9%) and shock (12.3%). The electrocardiography revealed relatively short QRS duration (123±18ms) and absence of ventriculoatrial dissociation in 33.3% of the patients, causing initial misdiagnosis in 29.8% of these patients. Patients with a VT onset age of <10years were more likely to have a left bundle branch block morphology (52.2% vs. 11.8%, p=0.001) and spontaneous recovery than those with a VT onset age of ≥10years. An electrophysiology study in 44 patients revealed that the most common arrhythmia focus was the left ventricular septal area (78%), called fascicular VT. Radiofrequency ablation showed a satisfactory success rate (90%) and fair recurrence rate (14.3%). Tachycardia-induced cardiomyopathy was noted in 14% of the VT patients and cardiac function returned to normal in 1–18months (median, 3months) after successful ablation. ConclusionsIn an Asian pediatric population, VT has distinct electrophysiological characteristics including dominant left ventricular origin, narrower QRS duration, and more symptomatic presentation. Transcatheter ablation is effective against VT, and the associated cardiomyopathy often resolves rapidly after successful ablation.

The dream of near-zero X-rays ablation comes true.

While radiation exposure related to natural sources plays a minor role, medicine-related exposure, represents, to date, a major exposure source. Within this exposure interventional electrophysiology is a relevant contributor. Unfortunately, no safe dose in radioprotection exists, the negative acute and long-term effects of radiological exposure may emerge at any radiation exposure dose. For this reason, patients and physicians should be aware of the risk of radiation exposure and the benefits of the imaging/procedure balanced by the required radiation exposure. Given this, performing a near to zero X-rays transcatheter ablation procedure should therefore represent an aim for all electrophysiological lab. Fortunately, the introduction of electroanatomic mapping systems, have provided the possibility to perform simple and complex electrophysiological procedures avoiding, or at least, limiting the use of radiations. The present review summarizes state of the art of feasibility and safety of the near to zero approach for the main electrophysiological procedures, highlighting the potential health benefits.

Procedural arrhythmia termination during beating-heart, stand-alone surgical ablation and long-term outcome in patients with persistent atrial fibrillation

Summary Objectives: Termination of atrial fibrillation (AF) during transcatheter ablation has been associated with improved outcomes in some studies. Our aim was to determine if termination of AF during beating-heart surgical ablation affects long-term results. Design and methods: This observational, retrospective study included 69 patients who underwent minimally invasive stand-alone surgical epicardial ablation for non-valvular, persistent AF using a bipolar ablation device. Patients with confirmed pulmonary vein isolation were included in the evaluation. Absence of arrhythmia was confirmed at 3, 6, and 12 months and annually thereafter with 24-h Holter monitoring. Results: Altogether, 39 (57%) patients were in AF at the beginning of surgical procedure. Among them, 21 (54%) recovered their sinus rhythm (SR) during the ablation: 7 (18%) had AF termination during left atrial ablation, 14 (36%) had AF termination during right atrial (RA) ablation. The remaining 18 (46%) patients required cardioversion to achieve SR. The mean follow-up was 55 ± 24 months. There were no significant differences in the patients’ preoperative and intraoperative data. The percentages of patients without AF termination during ablation who experienced freedom from AF and antiarrhythmic medications at 1, 2, 3, 4, and 5 years postoperatively were 78%, 63%, 50%, 33%, and 43%, respectively. The corresponding percentages in patients with AF termination were 83%, 74%, 67%, 71%, and 75%, respectively. Conclusions: There is a trend towards better long-term results if arrhythmia was terminated during surgical epicardial ablation on beating heart. Termination of AF during RA ablation (observed in 36% of patients), suggests that AF is a biatrial disease in patients with persistent AF.

Current integrated approaches for the treatment of focal atrial tachycardia

Focal atrial tachyardia constitutes more than 10% of the supraventricular tachycardias and it could be responsible for the initiation of other atrial arrhythmias, like atrial fibrillation and atrial flutter. Frequently, the focal atrial tachycardia does not respond to the medical treatment, while a definitive cure is often obtained with radiofrequency transcatheter ablations and integrated minimally-invasive approaches (atrial appendage clip). This paper describes physiopathological mechanisms underlying the focal atrial tachycardia, its anatomical localizations, the clinical patterns and the fundamentals of the diagnosis. Finally, the more recent treatment strategies will be illustrated and discussed.

Long-term events following atrial fibrillation rate control or transcatheter ablation

Atrial fibrillation increases thromboembolic risk. Oral anticoagulation with antivitamin K (AVK) reduces thromboembolic event rate, but increases hemorrhagic risk. The aim of the present study was to describe long-term cerebral thromboembolic/hemorrhagic event rates in atrial fibrillation patients managed by rhythm control, pursued by atrial fibrillation transcatheter ablation (AFTCA), and rate control strategy. One thousand and five hundred consecutive patients referring to three medical care centers for atrial fibrillation were retrospectively divided into three groups: AFTCA maintaining AVK (group A); AFTCA discontinuing AVK (group B); and rate control strategy and AVK (group C). Thromboembolic and hemorrhagic events were recorded in 60 ± 28 months of follow-up. Thromboembolic events did not differ between the groups (5/500, 1% group A; 7/500, 1.4% group B; 11/500, 2.2% group C; P = 0.45), and hemorrhagic events were greater in group A (9/500, 1.8%) and C (12/500, 2.4%) than in group B (no events; P = 0.003). Among patients with CHA2DS2 VASc score 2 or less, thromboembolic events did not differ in the group discontinuing AVK (group B, 4/388, 1%) or not (group A, 1/319, 0.3%; P = 0.38), whereas hemorrhagic events were more common in patients on AVK (5/319, 1.5% group A and 3/175, 1.7% group C; P = 0.02) compared with those discontinuing AVK (0/388, group B). Following AFTCA (groups A and B), 299/1000 experienced atrial fibrillation relapses; all thromboembolic events (12/299, 4%) occurred within these patients (P < 0.001). Considering this multicenter design study, AVK continuation following AFTCA, especially within patients with low-to-intermediate thromboembolic risk, confers a hemorrhagic risk greater to the thromboembolic protective effect. All thromboembolic events following AFTCA occur within patients experiencing atrial fibrillation relapses; therefore, in patients with high thromboembolic risk routine rhythm monitoring is essential after AVK discontinuation.

Transcatheter Ablation of Idiopathic Ventricular Fibrillation in a Patient with ICD and Arrhythmic Storm

Transcatheter Ablation of Idiopathic Ventricular Fibrillation in a Patient with ICD and Arrhythmic Storm

Sports Eligibility After Risk Assessment and Treatment in Children with Asymptomatic Ventricular Pre-excitation.

Many studies concern the management of young patients with symptomatic Wolff-Parkinson-White (WPW) syndrome, but little information exists on the significance and prognosis of ventricular pre-excitation (VPE) in asymptomatic children. The aim of the study was to evaluate the risk of sudden death in young athletes with asymptomatic VPE by transesophageal electrophysiological study (TEEPS) and their sports eligibility after the risk assessment and/or ablative treatment. Ninety-one asymptomatic children and adolescents underwent TEEPS both at rest and during adrenergic stress (exercise testing or isoproterenol infusion). After electrophysiological testing, patients were assessed in the 36months of follow-up. Thirty-three patients (36.3%) had a benign form of VPE and were allowed to participate in competitions. Ten patients (11%) were at borderline risk; thus, sport eligibility was evaluated individually. Forty-eight patients (52.7%) showed inducible sustained atrioventricular reentrant tachycardia and/or atrial fibrillation (AF), 11 of whom (12.1% of total population) had a potential risk of sudden cardiac death due to AF inducibility during physical stress. Forty-five young athletes underwent transcatheter ablation (TCA). TCA was interrupted in 12 patients (26.7%) because of the high procedural risk linked to septal accessory pathway (AP) location. There were no TCA-related complications, and all patients remained asymptomatic during follow-up. Most of the young athletes with asymptomatic VPE may be allowed to participate in competitive sports after an adequate risk assessment and/or ablative treatment. However, in our opinion, special care should be taken to avoid procedural complications, which are unacceptable in asymptomatic patients.

Results of Cryoablation for Atrial Fibrillation Concomitant With Video-Assisted Minimally Invasive Mitral Valve Surgery

Interest in minimally invasive video-assisted mitral valve surgery (MIMVS) is rapidly growing. Data on concomitant atrial fibrillation (AF) ablation to MIMVS are still lacking. The present study investigates the long-term results of AF cryoablation concomitant to MIMVS. From October 2006-September 2014, 68 patients with mitral valve disease (age 65.9 ± 11.1 years, 34 men out of 68 patients, Euroscore log 5.4 ± 4.5) and drug-resistant AF underwent MIMVS via right minithoracotomy and concomitant left-sided AF endocardial cryoablation (Cryoflex Medtronic, Minneapolis, MN). Patients were independently followed up by cardiological outpatient visits and underwent electrophysiological study when indicated. In total, 44 out of 68 patients (64.7%) underwent mitral valve repair and 8 patients (11.8%) also received concomitant tricuspid valve surgery. One procedure was electively converted to full sternotomy (1.5%). Total clamp time was 97.6 ± 22.8 minutes. In March 2015, 60 patients were alive and completed the follow-up after a mean of 3.4 ± 2.0 years following the procedure. In all, 48 patients (80%) presented sinus rhythm throughout the whole follow-up. Freedom from AF was respectively 95%, 87%, and 72% at 1, 3, and 5 years, respectively. We recorded 2 pacemaker implants (3.3%). A total of 3 patients suffered symptomatic recurrences (2 atypical atrial flutter and 1 atrial fibrillation) and underwent transcatheter ablation-all the 3 patients remained in stable sinus rhythm for the remaining follow-up. In conclusions, given the favorable long-term sinus rhythm maintenance rates of concomitant cryoablation, MIMVS can also be offered to patients with symptomatic AF. AF transcatheter ablation may easily avoid further symptomatic recurrences.

Atrial fibrillation and female sex.

Atrial fibrillation is the most common supraventricular arrhythmia. Its prevalence increases with age and preferentially affects male patients. Over 75 years of age, however, female patients being more prevalent, the absolute number of patients affected is similar between sexes. Despite this, few data are available in the literature concerning sex-related differences in atrial fibrillation patients. The present systematic review therefore considers comorbidities, referring symptoms, quality of life, pharmacological approaches and trans-catheter ablation in female rather than in male atrial fibrillation patients in search of parameters that may have an impact on the treatment outcome. In brief, female atrial fibrillation patients more commonly present comorbidities, leading to a higher prevalence of persistent atrial fibrillation; moreover, they refer to hospital care later and with a longer disease history. Atrial fibrillation symptoms relate to low quality of life in female patients; in fact, atrial fibrillation paroxysm usually presents higher heart rate, leading to preferentially adopt a rate rather than a rhythm-control strategy. Female atrial fibrillation patients present an increased risk of stroke, worsened by the lower oral anticoagulant prescription rate related to the concomitant higher haemorrhagic risk profile. Trans-catheter ablation is under-used in female patients and, on the contrary, they are more commonly affected by anti-arrhythmic drug side effects.