The point on the treatment of arrhythmic storm.

Arrhythmic storm is a clinical emergency associated with high mortality, which requires multi-disciplinary management. Reprogramming of the implantable cardiac defibrillator (ICD) aimed at reducing shocks, adrenergic blockade using beta-blockers, sedation/anxiolysis, and blockade of the stellate ganglion represent the first simple and effective manoeuvres, but further suppression of arrhythmias with antiarrhythmics is often required. A low-risk patient (e.g. monomorphic ventricular tachycardia, functioning ICD, and haemodynamically stable) should be managed with a beta-blocker (possibly non-selective) plus amiodarone, in addition to sedation with a benzodiazepine or dexmedetomidine; in patients at greater risk (high burden and haemodynamic instability), autonomic modulation with blockade of the stellate ganglion and the addition of a second antiarrhythmic (lidocaine) should be considered. In patients refractory to these measures, with advanced heart failure, general anaesthesia with intubation and the establishment of a haemodynamic circulatory support should be considered. Ablation, performed early, appears to be superior in terms of mortality and reduction of future shocks compared with titration of antiarrhythmics.

Brugada syndrome: identification of subjects at risk and therapy.

Brugada syndrome mainly affects young subjects with structurally normal heart and can cause x syncope or sudden death due to ventricular arrhythmias, even as the first manifestation, in approximately 5-10% of cases. To date, two questions remain open: how to recognize subjects who will experience arrhythmic events and how to treat them. The guidelines suggest treating subjects with a previous history of cardiac arrest or arrhythmogenic syncope, while they are unconclusive about the management of asymptomatic patients, who represent ∼90% of Brugada patients. We recently demonstrated that in asymptomatic patients, the presence of spontaneous Brugada type 1 electrocardiogram (ECG) pattern and inducibility of ventricular arrhythmias at electrophysiological study allows us to identify a group of patients at greater risk who deserve treatment. Regarding treatment, there are three options: implantable cardioverter defibrillator, drugs, and epicardial transcatheter ablation. Recent studies have shown that the latter is effective and free from serious side effects, thus opening a new scenario in the treatment of Brugada patients at risk. Subjects who present drug-induced-only type 1 Brugada ECG pattern, in whom a spontaneous type 1 pattern has been ruled out with repeated ECGs and 12-lead 24-h Holter monitoring, represent a very low-risk group, provided they adhere to behavioural recommendations and undergo regular follow-up.

Use of the advisor™ HD Grid mapping catheter in transcatheter ablation of atrial arrhythmias in palliated CHD and children without CHD.

OBJECTIVE: In this study, we describe our experience utilising Advisor™ High Density (HD) Grid mapping catheter in transcatheter ablation of intraatrial re-entrant and focal atrial tachycardias with or without CHD. METHODS: Forty-five consecutive patients with intraatrial re-entrant and focal atrial tachycardia who underwent a transcatheter ablation procedure by using Advisor™ HD Grid mapping catheter and high-density mapping system in our hospital from January 2017 to January 2023 were included into the study. RESULTS: The mean age of the patients was 14.2 ± 7.3 years (6-32 years), and the mean weight was 48.3 ± 16.2 kg (22-83 kg). Of the total 45 patients, 21 were intraatrial re-entrant tachycardia and 25 were focal atrial tachycardia. Of the 21 re-entrant circuits, 15 were classified as cavotricuspid isthmus-dependent and 5 were non-cavotricuspid isthmus-dependent. In one patient, two re-entrant circuits were identified. A transbaffle ablation was successfully performed from the left atrium in one patient. Of the 25 focal atrial tachycardia, 19 were from right atrium and 6 were from left atrium. A cryoablation was performed in only one patient and radiofrequency ablation in others. The mean procedure time was 180 ± 64 minutes. The mean follow-up period was 69.3 ± 35.3 months. Acute success was 95.5%. Recurrence was noted in two patients (4.4%). CONCLUSION: Advisor™ HD Grid mapping catheter was found to be safe and achieved an acceptable success in transcatheter ablation of patients with intraatrial re-entrant tachycardia and focal atrial tachycardias.

AFA-Recur: an ESC EORP AFA-LT registry machine-learning web calculator predicting atrial fibrillation recurrence after ablation.

AIMS: Atrial fibrillation (AF) recurrence during the first year after catheter ablation remains common. Patient-specific prediction of arrhythmic recurrence would improve patient selection, and, potentially, avoid futile interventions. Available prediction algorithms, however, achieve unsatisfactory performance. Aim of the present study was to derive from ESC-EHRA Atrial Fibrillation Ablation Long-Term Registry (AFA-LT) a machine-learning scoring system based on pre-procedural, easily accessible clinical variables to predict the probability of 1-year arrhythmic recurrence after catheter ablation. METHODS AND RESULTS: Patients were randomly split into a training (80%) and a testing cohort (20%). Four different supervised machine-learning models (decision tree, random forest, AdaBoost, and k-nearest neighbour) were developed on the training cohort and hyperparameters were tuned using 10-fold cross validation. The model with the best discriminative performance on the testing cohort (area under the curve-AUC) was selected and underwent further optimization, including re-calibration. A total of 3128 patients were included. The random forest model showed the best performance on the testing cohort; a 19-variable version achieved good discriminative performance [AUC 0.721, 95% confidence interval (CI) 0.680-0.764], outperforming existing scores (e.g. APPLE score: AUC 0.557, 95% CI 0.506-0.607). Platt scaling was used to calibrate the model. The final calibrated model was implemented in a web calculator, freely available at http://afarec.hpc4ai.unito.it/. CONCLUSION: AFA-Recur, a machine-learning-based probability score predicting 1-year risk of recurrent atrial arrhythmia after AF ablation, achieved good predictive performance, significantly better than currently available tools. The calculator, freely available online, allows patient-specific predictions, favouring tailored therapeutic approaches for the individual patient.

Atrial fibrillation fundamentals: from physiopathology to transcatheter ablation.

Atrial fibrillation (AF) is a common and harmful arrhythmia. Its complex pathogenesis can be outlined using Coumel's Triangle, that considers at the base of AF three different factors: substrate, trigger, and catalyst factor. The triangle can serve as a guide to understand the mechanism of action of the different possible treatments. Anti-arrhythmic drug therapies have a modest efficacy and no proven benefit on prognosis. Interventional therapy is more effective, especially if employed in the first stages of the disease, and can reduce mortality in selected populations. Ablative schemes must be different depending on the type of AF (paroxysmal, persistent) and the presence or absence of atrial dilation.

Atrial fibrillation in heart failure: drugs or ablation?

Atrial fibrillation (AF) and heart failure (HF) frequently coexist and mutually exert negative influences with important clinical implications. Although there is evidence that restoring and maintaining sinus rhythm may have favourable clinical effects in patients with HF, there is no evidence of a survival benefit with pharmacological antiarrhythmic intervention compared with a heart rate control strategy. In these patients, transcatheter ablation (CA) of AF represents a procedure with an excellent safety profile in centres with expertise and a high volume of interventions. However, in the absence of definite evidence of benefit on major clinical end-points that can be generalized to the heterogeneous population with AF and HF, the option of CA should be discussed and shared with the patient, and mainly considered in patients with conditions that are associated with a greater prospect of clinical benefit, such as 'young' age (65-70 years), good health conditions and few or no comorbidities, recent onset of HF and AF (especially if with high heart rate), left atrial volume not excessively compromised (<55 mm in diameter), and without evidence of substantial fibrotic remodelling, left ventricular ejection fraction (LVEF) >25%, including HF with preserved EF (HFpEF).

3D transvenous radiofrequency ablation of manifest epicardial posterior-septal accessory pathways in children: Can technology innovations improve the outcome?

INTRODUCTION: The aim of the study was to revise our more recent experience about epicardial posterior-septal accessory pathways radiofrequency transcatheter ablation in children and young patients using a transvenous approach through the coronary sinus, to understand if new mapping and ablation technologies can increase success rate and safety. METHODS AND RESULTS: Twenty children (mean age 13 ± 3 years) with epicardial posterior-septal accessory pathways (14 in coronary sinus and 6 in the middle cardiac vein) underwent radiofrequency transcatheter ablation with CARTO-3® system with help of the CARTO-Univu® module. Acute success rate was 73%. No patient was lost to follow-up (mean time 11.4 ± 9 months). The recurrence rate was 19%. Two patients underwent a successful redo-procedure; the overall long-term success rate was 65%. Navistar® catheter presented the highest acute success rate in the coronary sinus. Navistar SmartTouch® was the only catheter that did not present recurrences after the acute success, and it was successfully used in two patients previously unsuccessfully treated with a Navistar ThermoCool®. Acute success rate was 79% without image integration with angio-CT, while it was 63% after the introduction of CARTO-Merge®. CONCLUSION: Epicardial posterior-septal accessory pathways can be definitively eliminated by transvenous radiofrequency transcatheter ablation in more than half of the cases in children. Acute success rate does not seem to depend on catheters used, but contact-force catheter seems to be useful in cases with recurrences. Image integration with cardiac-CT does not increase success rate, but it is useful to detect coronary sinus alterations to better guide ablation strategy.

Transcatheter ablation for atrial fibrillation in patients with hypertrophic cardiomyopathy: Long-term results and clinical outcomes.

INTRODUCTION: Radiofrequency transcatheter ablation (RFCA) for atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) has been proven feasible. However, the long-term results of RFCA and its impact on clinical course of HCM are unknown. The aim of this study was to analyse clinical outcomes and long-term efficacy of RFCA in a multicentre cohort of patients with HCM and concomitant AF. METHODS: Patients with HCM and AF consecutively undergoing RFCA were included. Ablation failure was defined as recurrence of AF, atrial tachycardia, or flutter lasting more than 3 min and occurring after the blanking period. RESULTS: Overall, 116 patients with symptomatic AF refractory to antiarrhythmic drugs were included. Over a median follow-up of 6.0 years (interquartile range: 3.0-8.9 years) recurrence rate after a single RFCA was 32.3 per 100 patient/years with 26% of patients free from AF relapses at 6-year follow-up. Among patients experiencing AF recurrence, 51 (66%) underwent at least one redo-procedure. The overall recurrence rate considering redo-procedures was 12.6 per 100 patients/years with 53% of patients free from AF relapses at 6 years. At last follow-up, with an average of 1.6 procedures, 67 (61%) patients were in sinus rhythm (SR). Patients remaining in SR showed better functional status compared with those experiencing arrhythmic recurrences (NYHA Class 1.6 ± 0.1 vs. 2.0 ± 0.1, p = .009). CONCLUSIONS: RFCA of AF in HCM patients is an effective and safe strategy favoring long-term SR maintenance, reduction of atrial arrhythmic events, and improved functional status. However, most patients need repeat procedures and continuation of antiarrhythmic drugs.

Catheter ablation in atrial fibrillation: is there a mortality benefit in patients with diabetes and heart failure?

Atrial fibrillation (AF) is the most commonly sustained arrhythmia, and patients with diabetes mellitus (DM) exhibit an increased incidence of AF. Besides DM, heart failure (HF) shares pathophysiological links with AF, mainly related to the pathological remodeling of hearts affected by structural disease. As in a vicious circle, AF may contribute to HF worsening and increased mortality in patients with structural heart diseases, and the outcome may be further impaired when concomitant DM is present. Although no data directly referring to DM patients with HF are available, indirect information can be drawn from large studies on patients with HF and AF. The present review discusses the outcome of AF ablation in patients with DM and HF, focusing on safety, efficacy, and most particularly on hard endpoints such as mortality and thromboembolic event incidence.

Incidence of cerebral thromboembolic events during long-term follow-up in patients treated with transcatheter ablation for atrial fibrillation.

AIMS: Net clinical benefit of long-term oral anticoagulation therapy (OAT) continuation after successful atrial fibrillation (AF) ablation is still controversial. To evaluate long-term thromboembolic (TE) and haemorrhagic events incidence according to OAT strategy used after AF transcatheter ablation. METHODS AND RESULTS: Three months after AF ablation, OAT was discontinued in patients with CHADS2 ≤ 1 if no recurrences were documented, while OAT was maintained in patients with CHADS2 ≥ 2 regardless of AF recurrences. CHA2DS2VASc and HAS-BLED scores have been retrospectively evaluated. Seven hundred and sixty-six patients were followed for a median of 60.5 months. Six (6/267 = 2.2%) and five (5/499 = 1%) TE events occurred in the ON and the OFF-OAT patients, respectively (P = 0.145), all in concomitance with the AF recurrence. CHADS2 and CHA2DS2VASc ≥ 2 were associated with high TE incidence (P = 0.047 and P = 0.020). Among patients with a CHADS2 score of 0 or 1, a CHA2DS2VASc score ≥ 2 was predictive of TE events (P = 0.014). Overall, the incidence of the TE events in patients with CHA2DS2VASc ≥ 2 was 0.6 per 100 patient-years whereas seven haemorrhagic events occurred, all of them in the ON-OAT patients (7/267 = 2.6%). CONCLUSION: Patients with AF undergoing transcatheter ablation have a lower incidence of TE events as compared with the general AF population, regardless of OAT maintenance. The unpredictable risk of AF recurrence, mandate the routine use of the CHADS2, CHA2DS2VASc, and HAS-BLED scores to guide clinical decision regarding OAT management in this peculiar setting of patients. The potential protective role of rhythm control strategy in the TE events needs to be confirmed by future large randomized trials.

Symptomatic and asymptomatic long-term recurrences following transcatheter atrial fibrillation ablation.

BACKGROUND: Atrial fibrillation (AF) relapses, following transcatheter AF ablation, are frequently reported based on patients' symptoms, scheduled electrocardiograms (ECGs), or 24-hour Holter recordings. The aim of this study is to determine the incidence of asymptomatic and symptomatic AF recurrences, using continuous subcutaneous ECG monitoring, in the long-term follow-up of patients with paroxysmal or persistent AF undergoing transcatheter ablation. METHODS AND RESULTS: In total 113 consecutive patients symptomatic for paroxysmal or persistent AF were enrolled. All patients underwent pulmonary vein isolation plus left linear lesions. The insertable cardiac monitor (ICM), subcutaneously implanted during the ablation procedure, recorded the amount of AF per day (daily burden) and per last follow-up period (total AF burden). Based on symptoms and on scheduled 12-lead ECG performed during follow-up, 40 patients (35.4%) suffered AF recurrences. By means of ICM data, however, arrhythmia relapses were recorded within 75 patients (66.3%), of whom 35 (46.7%) were asymptomatic. Patients suffering symptomatic AF recurrences resulted, at univariate analysis, older (66.6 ± 8.4 years vs 61.6 ± 10.7 years) and suffering greater AF burden (88.8 ± 26.9% vs 8.0 ± 8.0%). CONCLUSIONS: AF ablation outcome based on patients' symptoms and/or scheduled ECGs underestimated relapses, as up to half of the patients, during a long-term follow-up, suffer asymptomatic recurrences.

Transcatheter options for atrial fibrillation treatment: an overview of the ablative techniques currently available and future perspectives.

Atrial fibrillation (AF) is the most common arrhythmia in the adult population and catheter ablation has emerged as an important rhythm-control strategy and is the most common cardiac ablation procedure performed worldwide. The antiarrhythmic drugs have demonstrated moderate efficacy in long-term maintenance of sinus rhythm; moreover, they are often not tolerated and are associated with adverse events. Catheter ablation has proven to be effective in treating AF, although long-term outcomes have been significantly less favorable in persistent AF than in paroxysmal. The current guidelines recommend catheter ablation as class I indication for patients whom antiarrhythmic drugs have failed or are not tolerated, and as first-line rhythm-control therapy in selected patients with symptomatic AF. Advances in technology and innovative ablation protocols resulted in a remarkable improvement of the efficacy outcomes after pulmonary vein isolation. This review seeks to provide an updated report of the current practices and approaches, and to describe the latest advances in technology that aim to improve procedural safety, efficacy and to reduce procedural requirements in terms of duration and fluoroscopy exposure.

Combination of percutaneous left appendage epicardial ligation and endo-epicardial atrial fibrillation ablation.

Introduction: Atrial fibrillation (AF) is the main cause of cardioembolic stroke. In high-bleeding-risk patients, long-life anticoagulation therapy is not permitted, and left atrial appendage (LAA) closure may be considered. LAA is also a critical substrate for AF. Epicardial LAA occlusion has several advantages: LAA ligation results in a favorable electrical and structural atrial remodeling, which decreases AF recurrence. Endocardial ablation alone is not efficient for all patients, and new evidence shows better outcomes in patients affected by persistent AF after a combined hybrid endo-epicardial ablation. Considering the synergic potential of these techniques, in this case series, they were both combined in a single procedure. Methods and results: We describe the treatment of 5 patients referred for refractory AF ablation and LAA closure. All patients had high thrombotic and previous major hemorrhage, with relative contraindication to life-long therapy with anticoagulation. A combined procedure of LAA ligation and endo-epicardial ablation was scheduled with short-term anticoagulation. LAA closure was performed with an epicardial approach using the LARIAT system. Then, LA mapping and ablation were performed, endocardially and then epicardially.All procedures were concluded without complications.At follow-up, in all patients, transesophageal echocardiography showed the complete occlusion of the LAA; therefore, anticoagulation therapy was interrupted. All patients were asymptomatic, and in the sinus rhythm, no hemorrhage or ischemic events occurred. Conclusion: The combination of percutaneous LAA ligation and endo-epicardial ablation was revealed to be feasible and safe and might represent a new approach for the treatment of refractory AF in patients with indication of LAA occlusion.

Diagnosis and Treatment of Idiopathic Premature Ventricular Contractions: A Stepwise Approach Based on the Site of Origin.

Premature ventricular contractions in the absence of structural heart disease are among the most common arrhythmias in clinical practice, with well-defined sites of origin in the right and left ventricle. In this review, starting from the electrocardiographic localization of premature ventricular contractions, we investigated the mechanisms, prevalence in the general population, diagnostic work-up, prognosis and treatment of premature ventricular contractions, according to current scientific evidence.

State of the art paper: Cardiovascular CT for planning ventricular tachycardia ablation procedures.

In the last 20 years coronary computed tomography angiography (CCTA) gained a pivotal role in the evaluation of patients with suspected coronary artery disease (CAD) as finally recognized by the ESC guidelines on stable CAD. Technological advances have progressively improved the temporal resolution of CT scanners, contemporary reducing acquisition time, radiation dose and contrast volume needed for the whole heart volume acquisition, further expanding the role of cardiac CT beyond coronary anatomy evaluation. Aim of the present review is to discuss use and benefit of cardiac CT for the planning and preparation of VT ablation.

Ablation of Atrioventricular Nodal Re-Entrant Tachycardia Combining Irrigated Flexible-Tip Catheters and Three-Dimensional Electroanatomic Mapping: Long-Term Outcomes.

BACKGROUND: Transcatheter ablation is the standasrd treatment for atrioventricular nodal re-entrant tachycardia (AVNRT). However, different techniques are available. Data about the use of irrigated flexible-tip catheters and three-dimensional electroanatomical mapping (3D EAM) for AVNRT ablation are scant. The aim of this study was to evaluate in long-term follow-up efficacy and safety of a novel approach for AVNRT treatment. METHODS: This is a cohort single arm study with long-term follow-up. Patients with AVNRT were treated with catheter ablation by means of irrigated flexible-tip catheters combined with 3D EAM. RESULTS: One-hundred-and-fifty patients were enrolled and followed-up for a median of 38 months (minimum 12, maximum 74). Acute procedural success rate was 96.7% (145/150 patients). During follow-up, 11 patients had arrhythmia recurrences (7.3%). No patient developed atrioventricular conduction block with need for pacemaker implantation (0%). Fourteen patients died during follow-up (9.3%). CONCLUSIONS: Acute procedural success and long-term follow-up show that AVNRT could be safely and effectively treated with irrigated flexible-tip catheters and 3D EAM.

Abnormal venous return: Still a challenge for electrophysiology procedures? A case report.

Catheter ablation of cardiac arrhythmias is usually performed through the femoral venous approach. Systemic venous return anomalies such as interruption of the inferior vena cava may represent a challenge during electrophysiological procedures. A 55-year-old patient with previous surgical correction of abnormal pulmonary venous return was admitted for poorly tolerated atrial flutter recurrences. He also had an interrupted inferior vena cava continuing as azygos vein and left superior vena cava draining via coronary sinus into the right atrium. Cavotricuspid isthmus radiofrequency ablation was successfully performed through the persistent left superior vena cava using a three-dimensional (3D) electroanatomical mapping system. Despite systemic venous abnormalities may potentially have important implications during electrophysiological procedures, arrhythmias can be successfully ablated with the aid of 3D electroanatomical mapping systems. .

Prevalence and Clinical Significance of Latent Brugada Syndrome in Atrial Fibrillation Patients Below 45 Years of Age.

Aim: This study aims to describe prevalence and clinical significance of latent Brugada syndrome (BrS) in a young population with atrial fibrillation (AF). Methods: Between September 2015 and November 2017, among 111 AF patients below 45 years of age, those without pre-existing pathologies and/or known risk factors were selected for the study. Based on baseline 12-lead-24-h Holter electrocardiogram (ECG), previous class 1C antiarrhythmic drug therapy, or ajmaline testing, patients were stratified as latent type 1 BrS or not. Results: Within the 78 enrolled patients, 13 (16.7%; group 1) revealed a type 1 BrS ECG pattern, while 65 (83.3%; group 2) did not. Mean age was 37 ± 8 vs. 35 ± 7 (p = 0.42), and males were 7 (54%) vs. 54 (83%) (p = 0.02) in the two groups, respectively. Family history of BrS was significantly more common within group 1 patients (2, 15% vs. 0; p = 0.03), and 4 (31%) patients experienced syncope in group 1 vs. 5 (8%) in group 2 (p = 0.02). After a mean follow-up of 42 ± 18 months from the index AF event, more than 80% of the patients, in both study groups, were in sinus rhythm. Conclusion: In young patients with AF without pre-existing pathologies and/or known risk factors, latent BrS should be suspected. Syncope and a family history of BrS emerge as easily identifiable factors related to BrS. Long-term sinus rhythm maintenance appears satisfactory, either in the presence or not of BrS.

Ablation in Pediatric Patients and in Association with Congenital Heart Disease.

Transcatheter ablation (TA) for treatment of pediatric tachyarrhythmias was first introduced in the early 1990s. Since then, its use as an alternative to antiarrhythmic drugs to treat supraventricular tachycardias caused by accessory pathway has been increasing. Nowadays, TA can be performed with high success rates and low complication rates even in very young children. Recently, the use of different types of energy (radiofrequency and cryoenergy), special ablation catheters, and 3D nonfluoroscopic mapping systems equipped with high technological tools has further improved safety and efficacy of TA, especially in difficult substrates and in patients with congenital heart disease.

Transseptal or retrograde approach for transcatheter ablation of left sided accessory pathways: a systematic review and meta-analysis.

BACKGROUND: Transcatheter ablation is the most effective treatment for patients with symptomatic or high-risk accessory pathways (AP). At present, no clear recommendations have been issued on the optimal approach for left sided AP ablation. We performed this meta-analysis to compare the safety and efficacy of transaortic retrograde versus transseptal approach for left sided AP ablation. METHODS AND RESULTS: MEDLINE/PubMed and Cochrane database were searched for pertinent articles from 1990 until 2016. Following inclusion/exclusion criteria application, 29 studies were selected including 2030 patients (1013 retrograde, 1017 transseptal) from 28 observational single Centre studies and one randomized trial. Patients approached by transseptal puncture presented a significantly higher acute success (98% vs. 94%, p = 0.040). The incidence of late recurrences (p = 0.381) and complications (p = 0.301) did not differ among the two groups, but the pattern of complications differed: vascular complications were more frequent with transaortic retrograde approach, while cardiac tamponade was the main transseptal complication. No difference was noted in terms of procedural duration and fluoroscopy time (p = 0.230 and p = 0.980, respectively). Meta-regression analysis showed no relation between year of publication and acute success (p = 0.325) or incidence of complications (p = 0.795); additionally, no direct relation was found between age and acute success (p = 0.256) or complications (p = 0.863). CONCLUSIONS: Left sided AP transcatheter ablation is effective in around 95% of the cases, with a very limited incidence of complications. Transseptal access provides higher acute success in achieving AP ablation; late recurrences are rare but observed similarly following both approaches. Retrograde approach is affected by a relatively high incidence of vascular complications.