Antiarrhythmic Research Articles

Propranolol in polymorphic ventricular premature beats

Abstract Background Therapy of polymorphic premature ventricular contractions (pPVC) is sometimes challenging despite improved catheter ablation options especially in patients suffering from non-ischemic cardiomyopathy. Previous studies have proven the benefit of non-selective ß-blocker such as propranolol in the stetting of electrical storm. Data for the use of propranolol to treat pPVC is sparse. Aim We sought to analyze the potential benefit of propranolol in the setting of failed or only partially successful pPVC ablation. Methods This retrospective analysis included patients (pts) undergoing catheter ablation (CA) for pPVC or pPVC triggered ventricular tachycardia (VT) at our center between January and October 2023. If ablation was unsuccessful or not all PVCs were completely abolished oral propranolol was started after the procedure. Propranolol replaced selective ß-blocker in case of preexisting medication. The dosage was up titrated to 240mg/d if feasible. No other antiarrhythmic drug was administered simultaneously. Follow-up (FU) was conducted 3 months after ablation. During FU visit at least one 24-48h ecg was obtained to assess PVC burden. Results A total of 13 CA in the setting of pPVC with propranolol naive patients were performed (mean age 62.6±10.3 years, 10 pts (77%) male; 6 patients suffering from non-ischemic cardiomyopathy). The mean left ventricular ejection fraction (LVEF) was 46.6±14.6%. Five patients had previous catheter ablation. Site of ablation was: 2 left papillary muscle, 2 outflow tract (RVOT), 7 great cardiac vein/ left ventricluar summit, 1 moderator band and 1 lateral mitral valve annulus. In all cases only transient or moderate pPVC suppression was achieved by CA. After a mean follow-up (FU) of 113.3±30.2 days a complete 3-month FU was obtained in 11 pts. The preprocedural mean pPVC burden of 14.0±7.7% was significantly reduced using propranolol to 4.2±7.7%; p=0.03 within three month after CA. No major propranolol complications occurred. Conclusion Data on the use of propranolol in the setting of pPVC is sparse. This analysis demonstrates for the first time a significant burden reduction of pPVC after starting propranolol in patients with failed or incomplete CA for pPVCs. Of note, although patients suffering from HFmrEf and HFrEF were included no clinical deterioration of preexisting heart failure was observed. Further comparative studies are needed.Propranolol PVC burden

The multicenter ablate-by-LAW study: personalized paroxysmal atrial fibrillation ablation according to the local left atrial wall thickness

Abstract Background Personalized radiofrequency (RF) catheter ablation for paroxysmal atrial fibrillation (PAF), tailoring the ablation index (AI) to the local left atrial wall thickness (LAWT), has proven to be an efficient procedure with high arrhythmia-free survival rates. However, to date, only monocentric experiences have been reported in the literature. Purpose The present study sought to report a multicenter experience in order to assess the safety, efficacy, and efficiency, of a LAWT-guided personalized pulmonary vein isolation (PVI) approach for PAF ablation (ClinicalTrials.gov, NCT04218604). Methods We conducted an international multicenter prospective study at five tertiary hospitals (two in Spain, one in Italy, one in Germany, and one in the United States). Consecutive patients referred for first-time RF catheter ablation of PAF were prospectively enrolled from November 2020 to September 2022. In all patients a three-dimensional map of LAWT were obtained from preprocedural multidetector computed tomography (MDCT)-derived data postprocessing. LAWT was categorized into 1 mm layers and AI was titrated according to the LAWT. All procedures were performed under general anesthesia, utilizing high-rate low-tidal volume (HR-LTV) ventilation (Figure 1). All antiarrhythmic drugs were discontinued following the 3-month blanking period. The primary endpoint was freedom from any documented sustained atrial arrhythmia at 12-month follow-up, regardless of symptoms. Results One hundred and nine patients (60.1±9.4 years, 64.2% male) were prospectively enrolled. The mean LA diameter was 38.7±5.8 mm and the mean left ventricular ejection fraction was 60.7±4.7%. The median procedure time was 61.7 minutes (IQR 48.4–83.8), and the median RF application time was 13.9 minutes (IQR 12.3–16.8). The mean number of VisiTags was 63.2 ± 18. First-pass PVI was achieved in the 83.5% of patients. The median fluoroscopy time was 61.5 seconds (IQR 22.5–197.5). In 94 (86.2%) patients, ablation was performed with a single femoral venous puncture. At 12-month follow-up, the rate of freedom from any documented atrial arrhythmia was 93.4% (Figure 1). Two (1.8%) patients died during follow-up, one from unknown cause three months after the procedure, and another from complications following multiple trauma after falling from a ladder. One patient (0.9%) developed femoral artery pseudoaneurysm, with no other serious procedure-related complications. Conclusion The Ablate-by-LAW multicenter study proved that a personalized PAF ablation protocol, tailoring the AI to the local LAWT is highly efficient and achieved a high acute first-pass PVI rates. The study reported a high 12-month survival-free from any documented sustained atrial arrhythmias, exceeding 90%, and an exceptionally low incidence of serious procedure-related complications.

Identifying patients with reduced risk of recurrences after ablation for persistent atrial fibrillation

Abstract Background Catheter ablation (CA) is a well-established treatment option for recurrent atrial fibrillation (AF), and has shown to outperform antiarrhythmic drugs in prevention of AF recurrences in numerous studies. However, up to 50% of patients with persistent AF (peAF) will experience recurrences after first-time CA. Improving treatment for these patients involves, choosing the right patients for the ablation procedure, optimizing the timing of the procedure, and using the most effective ablation strategy. This will benefit not only the patients, but also target recourse use in the healthcare system. Purpose To identify characteristics and comorbidities of patients with peAF associated with a reduced risk of recurrence after CA. Additionally, to investigate the optimal timing and ablation strategy. Methods This observational cohort study was conducted using real-life data from the Danish healthcare registries. All patients with peAF, >18 years of age, who were assigned to first-time AF ablation, were included within the study period from January 1st 2010 to December 31st 2018. A composite endpoint for AF recurrences was defined as either AF admission, electric cardioversion, use of antiarrhythmic drugs or re-ablation after a 3-month blanking period. We followed the patients in the registries for up to 5 years. A Cox proportional hazards analysis was performed to identify specific patient characteristics, comorbidities, timing of ablation and ablation strategy associated with reduced risk of AF recurrences after ablation. Results The study cohort consisted of 2,123 patients with peAF undergoing first-time CA. Median age was 63 years [IQR: 56.10;68.90], 77.7% were male, and mean BMI was 28.40 (SD: 4.97). Mean diagnosis-to-ablation-time (DAT) was 3.56 years (SD: 4.25) and mean follow-up time was 928.3 days (SD: 829.62). Most prevalent co-morbidities were hypertension (59.1%), ischemic heart disease (16.9%), and heart failure (HF) (27.7%) (Table 1). Patients characterized by male sex (HR: 0.80, 95% CI 0.69-0.93), age 60-70 (HR: 0.79, 95% CI 0.67-0.93), and absence of co-morbidities such as HF (HR: 0.81, 95% CI 0.70-0.94) and chronic obstructive pulmonary disease (COPD) (HR: 0.58, 95% CI 0.44-0-75), were observed with a significantly reduced relative risk of recurrent AF. Short DAT(<1 year) was associated with a 24% lower risk of recurrence compared to longer (>2 years). Furthermore, PVI Plus (additional ablation to PVI) was not significantly associated with a reduced risk of recurrences (HR: 1.10, 95% CI 0,92-1.31) (Figure 1). Conclusion To obtain rhythm control for patients with peAF is a great challenge. This observational study with more than 2,000 patients, identifies patients most likely to benefit from CA. Lower recurrence rates were observed in younger patients (<70 years), absence of especially HF and COPD, and early ablation (<1 year). Notably, PVI plus did not reduce the risk of recurrences.

Substrate characterization and outcomes of ventricular tachycardia ablation in amyloid cardiomyopathy: a worldwide study

Abstract Background the electrophysiological substrate underpinning ventricular tachycardia (VT) in cardiac amyloidosis (CA) remains elusive, and outcomes of catheter ablation in this peculiar population are currently unknown. Purpose we sought to describe the electrophysiological substrate and clinical outcomes of VT ablation in a cohort of patients with CA. Methods we included 19 consecutive patients (mean age, 69±10 years; male sex, 89%) with CA (ATTR, n=13; AL, n=6) undergoing catheter ablation for VT/ventricular fibrillation (VF) between 2013 and 2023 in a retrospective, observational, international study, involving 7 referral European and North American electrophysiology units. The primary efficacy outcome was recurrent VT/VF during follow-up, while the primary safety outcome included major procedure-related adverse events. Results the indication for ablation was drug-refractory VT in 16 patients (84%), and PVC-initiated polymorphic VT/VF in 3 (16%). Catheter ablation was performed using endocardial (n=14, 74%) or endo-epicardial approaches (n=5, 26%). Complete endocardial electroanatomical voltage maps of the left and right ventricles were obtained in 14 (74%) and 6 (32%) patients, respectively. Each patient had evidence of low-voltage areas, most commonly involving the interventricular septum (n=12); late potentials were recorded in 13 patients (68%). A median of 1 (1-2) VTs were inducible per patient; in 10 subjects (43% of mappable VTs), activation mapping was consistent with septal VT origin. Complete procedural success was obtained in 13 patients (68%), at the expense of 4 (21%) major procedure-related adverse events. After a median follow-up of 36 (18-54) months, sustained VT/VF recurrence was observed in 9 patients (47%); survival free from VT/VF recurrence was 74% (95%CI, 56-96%) at 12 months, and 53% (95%CI, 34-94%) at 36-month follow-up; the majority of patients remained on antiarrhythmic drugs (Figure). Low-voltage QRS (HR,21.96; p=0.022) and complete procedural success (HR,0.08; p=0.029) were associated with recurrent VT/VF at multivariable analysis (Figure). Conclusions catheter ablation of VT/VF is associated with favorable acute and mid-term arrhythmia control, yet with substantial risk of procedure-related complications and long-term recurrences. Septal substrate and frailty challenge successful management of patients with CA and VT/VF.Multimodality evaluation of LV substrateMain Study Outcomes

The impact of additional radiofrequency ablation for atrial fibrillation substrates using with ExTRa-Mapping analysis after Cryo-ablation in patients with persistent atrial fibrillation

Abstract Background Pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF) is well established. Cryo-ablation for persistent AF has been reported to be safe and effective and comparable to radiofrequency (RF) ablation in long term arrhythmia-free survival, but the outcome is limited. Phase mapping using software of ExTRa-Mapping is a new tool to clarify the real-time imaging of the AF wave dynamics. Purpose We investigated the distribution of rotors of left atrium (LA) after PVI by Cryo-ablation, and the efficacy and safety of additional RF ablation for AF substrates (rotor modification) after Cryo-ablation. Methods A total of 50 patients who underwent persistent AF ablation in our hospital were enrolled. The Cryo-ablation alone group (Cryo group; n=25) and the Cryo-ablation + additional RF substrates ablation group (Cryo+RF group; n=25) were randomly divided. First, PVI with Cryo-ablation was performed. Second, if AF did not term after PVI, the rotor of LA were analyzed using the NAVX and ExTRa-Mapping system. In Cryo+RF group, the extensive RF ablation of the PV antrum to modify the rotor area were performed (Abstract Picture 1). The recurrence rate of any atrial tachy-arrhythmia without anti-arrhythmic drugs and safety were evaluated in both groups. Results The patient characteristics (69 ± 9.2 years old, body-mass index 24 ± 3.2 kg/m2, LA diameter 43 ± 5.1 mm, left ventricular ejection fraction 60 ± 7.8 %, persistent AF duration 4.2 ± 5.1 months) did not differ between the both groups. The distribution of rotors of LA were predominantly present in the anterior (n = 36) and inferior (n = 27) walls of the LA, with only a few in the posterior wall (n = 7) in the both groups. In Cryo+RF group, except for 4 cases in which AF was termed by PVI or a rotor was not detected, extensive RF modification in anterior antrum of right pulmonary vein was performed in 18 of 21 cases. In an average follow-up of 482 ± 273 days, the recurrence rate of any atrial tachy-arrhythmia was significantly lower in Cryo+RF group compared with Cryo group (p=0.029, Abstract Picture 2). No serious complications occurred in both groups. Conclusion Additional extensive RF ablation of the PV antrum to modify the Rotor area resulted in a lower recurrence rate in patients with persistent AF.Modify the rotor areaRecurrence rate

Definition and management of arrhythmia-induced cardiomyopathy: findings from the EHRA SIC survey

Abstract Background Arrhythmia-induced Cardiomyopathy (AiCM) represents a subtype of heart failure (HF) in the context of a sustained arrhythmia. However, clear definitions and management recommendations for AiCM are lacking. Purpose The European Heart Rhythm Association Scientific Initiatives Committee (EHRA SIC) conducted a survey to determine the current definitions and management of patients with AiCM among European and non-European electrophysiologists. Methods A 25-item online questionnaire was developed and distributed among EP research network centres between September 4th and October 5th 2022. Results Out of the 206 respondents, 16% were females and the most (33%) were between 40-49 years old. Most of the respondents were EP-Specialists (81%) working at a University Hospital (47%). While most participants (67%) agreed that AiCM should be defined as a left ventricular ejection fraction (LVEF) impairment after new onset of an arrhythmia and/or LVEF recovery after treatment of the culprit arrhythmia, only 35% identified a specific LVEF drop/improvement to diagnose AiCM, the majority (50%) agreeing with a 10% change in LVEF (Figure) but with the rest of the experts choosing a wide range of values (from 5 to 20% LVEF drop). Most respondents used all available therapies in AiCM patients: catheter ablation was chosen by 93%, electrical cardioversion by 83%, antiarrhythmic drugs by 76% and adjuvant HF treatment were used by 76%. 83% of respondents indicated that adjuvant HF treatment should be started at first diagnosis of HF prior to antiarrhythmic treatment and 84% agreed that the therapy should be stopped within six months after LVEF normalization. Responses for the optimal time point for the first reassessment of LVEF during FU varied markedly (1 day to over 6 months after antiarrhythmic treatment). Conclusion This EHRA Survey reveals varying practices in defining and managing AiCM among European and non-European physicians. There is an unmet need for a consensus in the definition and management of AiCM patients to improve patient care.Figure

Comparison of QT interval readings between smartwatch ECG combined with artificial intelligence and 12-lead ECG in subjects hospitalized for antiarrhythmic drug initiation and follow-up

Abstract Background/Introduction Class III antiarrhythmic drugs (AADs) are effective for the maintenance of sinus rhythm (SR) in subjects with atrial fibrillation (AF). However, several require initial hospitalization for QT interval monitoring using the 12-lead ECG. Purpose The purpose of this study was to evaluate the feasibility of using a smartwatch single lead ECG combined with a deep learning algorithm for routine QT interval determination in the context of AAD initiation. Methods A deep learning model was developed using smartwatch and Holter ECG recordings to estimate corrected QT intervals. To evaluate the performance of this model, we carried out a prospective study on subjects hospitalized for initiation of sotalol and/or dofetilide. Subjects recorded near simultaneous (maximal 2 minutes apart) smartwatch ECGs (Apple Watch Series 6) and 12-lead ECG (Mac 5500 HD ECG or GE Carescape B450) right before and 2-3 hours after drug administration twice a day for 2-3 days. Blinded double annotation followed by adjudication of disagreement provided a reference heart rhythm (NSR or AF) and QTc interval. The tangent method was used for QTc interval determination. Bland-Altman analysis was performed to assess the agreement between QTc measures. Results Fifty subjects (mean age 67.4±10.9 years, 64% male) were enrolled in the study from February 2022 to October 2022. Out of 386 monitoring visits, 321 near simultaneous pairs of ECGs were collected with a mean delay of +15.0±41.1s for the smartwatch ECG compared to the 12-lead ECG. Overall, a mean QTcF reference value of 419.9±34.0 ms was observed (435.2±38.4 ms for QTcB, r=0.83 between annotators[BL2] ). Among the 139 pairs with 12-lead ECG found in NSR, we observed a mean QTcF difference of +19.7 ms and limits of agreements equal to -21.5 ms and 60.8 ms, with AI-facilitated measurement. In comparison, a mean QTcF difference of +22.5 ms and limits of agreements equal to -23.8 ms and 68.8 ms were observed for manual readings of smartwatch ECGs instead. Conclusion(s): Our findings suggest that a smartwatch ECG deep learning approach can estimate the QT interval with a fair agreement compared to standard 12-lead monitoring during AAD initiation. This measurement method appears to be at least as accurate as manual measurements on smartwatch ECGs. With further validation, the smartwatch-based automatic detection of QT interval prolongation, could be used for a faster, safe, and extended outpatient QT interval monitoring.Bland-Altman plots

Safety and efficacy outcomes in 100 consecutive cases of pulsed field ablation

Abstract Background Pulsed field ablation (PFA) an emerging technology for ablation of atrial fibrillation (AF). This non-thermal ablation modality uses ultrarapid electrical pulses to destabilise cell membranes and can selectively ablate myocardial tissue. Successful pulmonary vein isolation (PVI) and reductions in procedure times compared to other modalities have been observed in initial studies. Aim To report initial outcomes and fluoroscopic times in the first 100 consecutive cases using PFA in AF ablation. Methods The first 100 consecutive PFA cases carried out by a single operator in a single centre were examined. All cases were performed under general anaesthesia, using ultrasound-guided vascular access and TOE-guided transseptal puncture. Outcomes were recorded from the first case in June 2022 to the present day. Electroanatomic mapping (EAM) was carried out using two proprietary systems. Results Procedural information and follow-up was achieved in all 100 patients (see table). The majority (77) were male. Mean age 61. Cardiovascular comorbidities included: hypertension (41), heart failure (12), ischaemic heart disease (10), stroke (4), diabetes mellitus (3). Antiarrhythmic drugs were used by 45 patients (Amiodarone in 22, Dronedarone in 18, Flecainide in 10, Sotalol in 8, Mexiletine in 1) with 55 taking beta blockers only or no rhythm control drugs. Persistent AF accounted for 57 cases, and 91 patients had no prior ablation procedure. Median CHA2DS2VASC 1. Warfarin was used on 1 patient, the other 99 patients underwent ablation on uninterrupted DOAC, most commonly Apixaban. EAM was conducted in 59 patients. Stand-alone PVI was carried out in 68, while 30 underwent an additional posterior wall box isolation, and a mitral isthmus line was added in a further 2 who had atrial flutter (AFl) during the procedure following successful PVI. There were no serious peri-procedural complications. (vascular access complications, pericardial effusion, stroke or death). All 100 patients were discharged following a one-night stay. Clinical pericarditis without effusion occurred in 1 patient on day 2, and resolved with a short course of Colchicine. Mean fluoroscopy time was 9minutes, 12seconds, and reductions in fluoroscopy times correlated significantly with case number (see figure). Mean fluoroscopy time was 2mins, 30secs higher where EAM was used. Sinus rhythm was achieved in 100%. Atrial arrhythmia recurred in 12 patients, 7 with AF and 3 atrial flutter, 2 with typical symptoms which could not be documented. Two of the recurrences were within 24 hours of the procedure. Conclusions This registry data shows that PFA was used to achieve PVI safely, with effective additional substrate ablation also demonstrated. There were no serious peri-procedural complications, and procedural improvements in fluoroscopic times were observed throughout the 100 cases. Long term follow-up data is required to validate the safety and efficacy of this new technology.

Reduced heart failure hospitalizations and improved quality of life in cardiac amyloidosis patients undergoing atrial fibrillation ablation

Abstract Background Cardiac amyloidosis (CA) has been associated with an increased risk of atrial arrhythmias and development and worsening of heart failure due to infiltration of the amyloid protein in the atrial wall. Few data exist regarding prognosis, symptoms, and quality of life after catheter ablation of atrial fibrillation in this category of patients. Objective The study evaluates the outcome of hospitalization for heart failure and quality of life in cardiac amyloidosis patients with atrial fibrillation after catheter ablation. Methods This is a study including 102 consecutive patients from two different centers with an established diagnosis of amyloidosis ATTR that underwent their first AF catheter ablation for persistent AF. They underwent pulmonary vein (PV) isolation + isolation of left atrial posterior wall and superior vena cava. Additionally, extrapulmonary triggers were identified and ablated. Post procedure, patients were followed up routinely with ECG during office visits, 7-day Holter monitor and event recorders during the first year followed by biannual checkups during the remaining part of the follow-up period. Quality of life (QoL) was measured using The Minnesota Living Heart Failure Questionnaire (MLHFQ) before Catheter ablation and after 18 months follow up; QoL was compared with T-test. Results 102 patients (mean age 72 ± 6) were included in the study. After 18 months follow up, 72 patients (70.6%) remained arrhythmia-free without antiarrhythmic drugs (Group 1), whereas 30 patients (29.4%) experienced recurrence (Group 2). In Group 1, 9 patients were hospitalized for heart failure, in contrast to 18 patients in Group 2, indicating a higher rate of heart failure hospitalizations associated with arrhythmia recurrence (p=0.02). The Quality of life in group 1 was 62 ±12 points before ablation and 63±16 points at 18 months follow up (p=0.17) while in group 2 was 68±16 points before ablation and 86±12 points at 18 months follow up (p<0.001). Conclusion Catheter ablation for AF in patients with cardiac amyloidosis is associated with reduced hospitalizations for heart failure, along with improvement in QoL.

Efficacy of catheter ablation in patients with persistent atrial fibrillation on chronic ibrutinib therapy

Abstract Background Ibrutinib represents a cornerstone in the management of B-Cells malignancies and chronic lymphatic leukaemia. This drug however was associated with a 5-fold increased risk of developing atrial fibrillation (AF). The consequences of AF in this category of frailty patients such as heart failure may lead to the need of Ibrutinib withdrawal, which is considered a disease modifying therapy. Purpose This study aims to evaluate the safety and efficacy of catheter ablation in managing AF in patients on chronic ibrutinib therapy. Methods this study evaluated 20 consecutive patients from two centres in Italy who developed persistent AF during chronic therapy with Ibrutinib for chronic lymphatic leukaemia or small lymphocytic lymphoma and underwent AF catheter ablation from 2016 to 2020. Antiarrhythmic drugs were withdrawn because of side effects and drug interaction. All receive pulmonary vein (PV) isolation + isolation of left atrial posterior wall (PW) and superior vena cava. A standardized protocol was performed to confirm persistent PVI and elicit any triggers originating from non-PV sites. Ablation of non-PV sites triggering runs of atrial tachyarrhythmias was left to operator's discretion. Exclusion criteria were age<18 years and history of AF before ibrutinib therapy. Patients were monitored for arrhythmia at quarterly office visits, ECGs, 7-day Holter monitoring and event recorders during the first year followed by biannual checkups during the remaining part of the follow-up period. Results 12 patients received PV+PW+SVC isolation plus ablation of non-PV trigger (Group 1) whereas 8 receive only PV+PW+SVC isolation (Group 2). 10 (83,3%) patients in group 1 remained arrhythmia-free without the need for additional antiarrhythmic drugs while only 3 (37,5%) in group 2 maintained sinus rhythms. Non pulmonary triggers were mostly found in left atrial appendage (5/12, 41,6%), coronary sinus (4/12, 33,3%) and crista terminalis (3/12 25%). More than one trigger was found in 4 (33.3) patients. After 22.3 ±3.6 months follow-up, patients with ablation of induced non-PV triggers had a significantly higher arrhythmia control than those whose triggers were not ablated (Chi – square p value: 0.035; Log rank p value: 0.014) (Fig.1). 5 patient that received left atrial appendage isolation underwent a left atrial appendage closure with Watchman device 3 months after atrial fibrillation ablation. Conclusion Catheter ablation in this category of patients seems to be a safe and effective tool for managing atrial fibrillation in patients with persistent AF on chronic ibrutinib therapy; an ablation strategy that includes as a first line therapy non pulmonary vein triggers appears to be an effective approach when compared to pulmonary vein plus posterior wall only. This approach will allow continuation of ibrutinib treatment, which markedly enhances the prognosis and diminishes the risk of adverse cardiovascular events in this patient population.Kaplan-Meier curve showing recurrence-fr

Treatmen of atrial fibrillation with cryoballoon pulmonary vein isolation - results of a 5-year follow-up

Abstract Background Atrial fibrillation is the most common arrhythmia in the general population and cryoballoon ablation is gradually becoming a first-line treatment. However, data regarding long-term outcomes after this procedure are still lacking. Aim The goal was to show the results of a long-term follow-up following the cryoballoon pulmonary vein isolation in patients with atrial fibrillation (AF). Methods A total of 126 patients were included in the study of which 77.0% had paroxysmal atrial fibrillation (PAF). Successful treatment outcome was defined as AF recurrence-free survival with stabile sinus rhythm during 5 years after the procedure. A treatment failure was defined as symptomatic AF recurrence with ECG verification (12 lead ECG or AF lasting >30s by Holter EKG). The patients on antiarrhythmic therapy and those who underwent a redo pulmonary vein isolation procedure were also included. Results Following cryoballoon pulmonary vein isolation in a 5-year period 52.4% of patients were in stable sinus rhythm without AF recurrence. With redo pulmonary vein procedures a total of 61.9% of patients were without AF recurrence. Together with antiarrhythmic drugs 57.9% of patients were in sinus rhythm without AF recurrence in a 5-year period. With redo pulmonary vein isolation and antiarrhythmic drugs a total of 73.8% of patients were without AF recurrence. There was a statistically significant difference regarding AF recurrence between patients who underwent redo pulmonary vein isolation and those who did not (p=0.006). In patients with PAF, 62.9% remained without AF recurrence, and 79.4% underwent a redo procedure. In patients with persistent atrial fibrillation (PersAF), 41.4% were without AF recurrence, and 55.1% underwent a redo procedure. The difference between PAF and PersAF was statistically significant (p=0.009). Conclusion Data from our center show good long-term results of cryoballoon pulmonary vein isolation in patients with atrial fibrillation. The procedure is especially successful in patients with PAF.1 The use of redo procedures is justified as it increases the long-term success rate.

Prevalence of non pulmonary vein triggers and pulmonary pressure change in atrial fibrillation ablation for cardiac amyloidosis patients

Abstract Background Cardiac amyloidosis (CA) has been associated with an increased risk of atrial arrhythmias and high risk to develop pulmonary hypertension due to infiltration of the amyloid protein in the atrial wall. Though non-PV triggers are commonly seen in left atrium, they are also seen in the right side of the heart, so identifying them at the time of ablation is essential. Objective The study evaluates the prevalence of non-PV triggers during catheter ablation in atrial fibrillation (AF) patients affected by cardiac amyloidosis and how restoration of sinus rhythm affects pulmonary pressures. Methods This is a study including 74 consecutive patients with an established diagnosis of amyloidosis ATTR diagnosed with cardiac MRI or myocardial biopsy that underwent their first AF catheter ablation. All have a transthoracic echocardiogram before ablation. They underwent pulmonary vein (PV) isolation + isolation of left atrial posterior wall and superior vena cava. Additionally, extrapulmonary triggers, which are defined as ectopic triggers originating from sites other than PVs including left atrial appendage (LAA), coronary sinus (CS), interatrial septum, crista terminalis, mitral valve anulus were identified. Post procedure, patients were followed up routinely with ECG during office visits, echocardiogram, 7-day Holter monitor and event recorders during the first year followed by biannual checkups during the remaining part of the follow-up period. Student’s t-test was used to compare pulmonary pressure between the groups. Results Isoproterenol-challenge revealed non-PV triggers in 51 (68.9%) patients. These triggers were mostly mapped to LAA (39, 52.7%), CS (30, 40,5%), and crista terminalis (35, 47.3%). Besides, ectopic beats were seen originating from inter-atrial septum (19, 25.6%), mitral valve annulus (10, 13.5%). More than one trigger was found in (68%) patients. At 1-year after the ablation, 65 (87.8%) were arrhythmia-free off antiarrhythmic drugs. Moreover, in patients who maintained sinus rhythm post-ablation, there was either a non progression or a reduction in pulmonary pressures (PAPm before ablation: 44.8 ± 8.9 mmHg vs PAPm after ablation 45.1 ± 11.1 mmHg, P value =0.87). Conversely, those experiencing arrhythmic recurrences demonstrated an increase in pulmonary pressures (PAPm before ablation: 41.9 ± 7.7 mmHg vs PAPm after ablation 47.8 ± 10.2 mmHg, P value =0.019). Fig.1 Conclusion Our findings suggest that non-PV triggers are highly prevalent in cardiac amyloidosis AF patients including a high rate crista terminalis firing. Notably, restoration of sinus rhythm post-ablation was linked to stable or reduced pulmonary arterial pressures, whereas patients with arrhythmic recurrences experienced a significant increase.

High-resolution repolarization changes preceding short-coupled ectopy in idiopathic ventricular fibrillation, and effects of quinidine

Abstract Background Idiopathic ventricular fibrillation (VF) is linked to early repolarization, increased repolarization heterogeneity, and (short-coupled) premature ventricular complexes (PVCs). Quinidine, an antiarrhythmic drug with class-IA and -III effects, reduces the occurrence of PVCs and VF, but its effects on repolarization have not yet been studied at the whole-heart level in idiopathic-VF patients. Purpose To study dynamic changes in repolarization preceding short-coupled PVCs using noninvasive electrocardiographic imaging (ECGI) in a patient with idiopathic VF, and the antiarrhythmic effects of quinidine. Methods ECGI was performed during sinus rhythm in a 61-year-old male with an ICD (secondary prevention; 2.5 mg nebivolol daily) two days after recurrent idiopathic VF (Fig. A). This was done 1) at baseline, 2 minutes before short-coupled ectopy ("baseline"); 2) at baseline, 10 seconds before the short-coupled PVC ("pre PVC"); and 3) at 2 hours after start of quinidine 200 mg ("on-quinidine"). The ECGI procedure consisted of a 224-electrode body surface potential map and a contrast-enhanced CT scan to obtain torso and heart geometries. After reconstruction of epicardial unipolar electrograms (UEGs), local activation and repolarization times (ATs and RTs) were derived from UEGs by assessing the steepest downslope of the QRS complex and steepest upslope of the T waves, respectively, of 10-second signal-averaged beats. AT and RT duration (first to last AT or RT) were assessed. Results At baseline, QRS duration and QT interval measured 107 ms and 343 ms, respectively, on the standard 12-lead ECG. ECGI-derived epicardial AT duration was 72 ms, and RT histogram span 92 ms. The coupling interval of the PVC that triggered VF in the ICD readout was 340 ms (Fig. A). During 44 minutes of ECGI, 157 short-coupled PVCs from the moderator-band region were recorded (Fig. B; no tachycardia or VF). Just prior to a PVC, epicardial early repolarization at the PVC origin decreased by 26 ms (star in Figs. C-E), and the RT histogram broadened to 109 ms (Fig. E). While on-quinidine, (25 minutes; QRS duration 107 ms, QT interval 419 ms), epicardial repolarization was prolonged (Fig. C/D), also at the site of abnormal impulse formation. Quinidine had increased the epicardial AT duration to 79 ms, and RT histogram span to 133 ms. PVCs were completely suppressed. The patient remained free of sustained arrhythmias while on-quinidine. Conclusion(s) In this case of short-coupled idiopathic VF, epicardial early repolarization shortened momentarily prior to abnormal impulse formation. We found dynamic substrate-trigger characteristics that likely facilitate reentrant excitation. Quinidine prolonged the duration of epicardial activation and repolarization, suppressing the ectopy and VF recurrence.

Epicardial catheter ablation of ventricular tachycardia in patients of acm - from a university hospital report in switzerland

Abstract Background Arrhythmogenic left ventricular cardiomyopathy (ALVC) as a subtype of arrhythmogenic cardiomyopathy (ACM) is increasingly being recognized. Cardiac magnetic resonance (CMR) has emerged as the primary imaging modality for the diagnosis of ACM. In patients with right-dominant ACM (ARVC) and recurrent sustained ventricular tachycardia (VT), endocardial +/-epicardial ablation yields good clinical outcomes in the long-term. However, studies on VT ablation in ACM with LV involvement are scarce. Purpose We sought to investigate clinical outcomes of VT ablation in ACM patients with LV involvement. Methods The study included patients from the Zurich ACM Registry who met 2020 "Padua Criteria" for ACM and underwent VT ablation between January 2018 and July 2023. Epicardial ablation was performed in patients with recurrent sustained VT despite endocardial ablation, those lacking and endocardial substrate or if the ECG of the VT / substrate on CMR was suggestive of an epicardial origin. Catheter ablation was guided by activation/entrainment mapping for mappable VT, and pace mapping/voltage mapping during sinus rhythm for unmappable VT. Consecutive follow-up of all patients was performed according to our protocol. Results Twenty-one ACM patients underwent n=24 VT ablation procedures. Of those 20 patients, 6 patients (30%) had LV involvement on CMR. Eight (33%) patients underwent epicardial +/- endocardial ablation. Among patients receiving epicardial ablation, 3 patients (38%) had LV involvement. These three underwent a single ablation procedure, which was epicardial only. Total follow-up was 30 months (range 4-43). Three-month sustained VT/VF recurrence rates were 12% in the ACM group with LV involvement vs 25% in ACM without LV involvement. All patients with sustained VT/VF recurrence underwent repeat ablation via an epicardial approach within 3 months and were free of sustained VT/VF thereafter during a median follow-up of 12 months. One-year recurrence rate did not differ between ACM patients with LV involvement vs. without LV involvement (7.7% vs 8.3%, P＝0.117). Seven out of eight epicardial ablations achieved freedom from VT/VF after one-year follow-up. One ARVC patient with previous endocardial ablation had recurrent VT one month after epicardial ablation, which was free of VT after Flecainide combined with beta-blocker. No significant differences were found in the use of beta-blockers and antiarrhythmic drugs between both groups (ACM with LV involvement vs. without LV involvement) at baseline and during one-year follow-up. Conclusions Single or adjuvant epicardial substrate ablation of VT in arrhythmogenic cardiomyopathy is promising in terms of postprocedural VT free survival, especially in patients with left ventricular involvement demonstrated by CMR.Figure 1Figure 2

Arrhythmia during gestation: from diagnosis to follow-up

Abstract Background Although arrhythmia is common cardiac complication during gestation, data on perinatal and neonatal outcomes in pregnant women with different arrhythmia management is limited. Purpose To explore clinical characteristics and outcomes of different management strategies in pregnant women with arrhythmias. Methods In this single-center, prospectively study we consequently included 87 cases of arrhythmias in pregnant (mean age 26.7±3.5 years, mean gestation age 24.6 ±3.3 weeks). Clinical characteristics, obstetric and neonatal outcomes were compared due to different arrhythmia management strategies: dynamic observation (the 1st group), antiarrhythmic therapy (the 2nd group) and catheter ablation (the 3rd group) within 12 month follow-up. Results Supraventricular tachycardia (n=47; 54%) was the most common arrhythmia in pregnant. Premature contraction was detected in 34 cases (39%). Cases of ventricular tachycardia (n=6; 7%) was rare during gestation. Benign course of arrhythmia was in 15 cases (17.2%) and do not require drug therapy or intervention. Antiarrhythmic drug was used for symptomatic patients with haemodynamic instability (n=28, 32.2%). Catheter ablation performed in cases of drug refractory and severe arrhythmias (n=44, 50.5%). The procedure performed under the guidance of CARTO (n=21; 47.7%) and Ensite Precision systems (n=23; 52.3%) without fluoroscopy and were successful in all cases (100%). The further course of gestation characterized by occurring increased incidence of uterine contractile activity (n=2, 4.5%, p=0.464) and placental abruption (n=2, 4.5%, p=0.464) only after catheter ablation while other complications were in all groups: uterine blood flow violation (n=6, 40% vs. n=4, 14.3% vs. n=6, 13.6%, p=0.168) and preeclampsia (n=1, 6.7% vs. n=1, 3.6% vs. n=2, 4.5%, p=0.730). Obstetric outcomes characterized by prevalence of vaginal delivery in all groups (n=13, 86.7% vs. n=22, 78.6% vs. n=37, 84%, p=0.465). Neonatal outcomes characterized by normal range of fetal birth weight and 5 minute Apgar score in all groups (3140.7±321.2 vs. 3265,3±290,1 vs. 3312,3±209,8 grams, p=0.701 and 8,6±1,1 vs. 8,5±1,2 vs. 8,6±1,2, p=0.721 respectively). There was no incidence of maternal and fetal mortality and arrhythmia recurrence after ablation in follow-up. Conclusions Supraventricular tachycardia is common in pregnancy. Arrhythmias in pregnant characterized by benign gestation course and outcomes regardless different management.

Hybrid ablation versus repeated catheter ablation in persistent atrial fibrillation: long-term results of the HARTCAP-AF trial

Abstract Background The HARTCAP-AF study compared the efficacy and safety outcomes in forty-one ablation-naive patients with persistent atrial fibrillation (AF) randomized to thoracoscopic hybrid ablation (HA) or stand-alone catheter ablation (CA). One-year results have shown that thoracoscopic HA has superior rhythm outcomes than CA, without increasing complications. Purpose Here, we evaluated the efficacy, safety and quality of life (QOL) of thoracoscopic HA and CA within a long-term follow-up (FU) duration of three years. Methods Efficacy outcomes included freedom from atrial tachyarrhythmia (ATA) recurrences ≥5 minutes off and allowing antiarrhythmic drugs (AAD) after 24 and 36 months. Safety outcomes, including serious adverse events (SAEs), and QOL, measured by the EHRA AF symptom score, were evaluated after 36 months. Results After a mean FU duration of 25±3 and 38±3 months, freedom from ATA recurrences was higher in the HA group compared to the CA group off AAD (68.4% vs. 22.7%, P=0.002 and 57.0% vs. 22.7%, P=0.005) and allowing AAD (73.7% vs. 22.7%, P=0.001 and 63.2% vs. 22.7%, P=0.001) (Figure 1, Table 1). The number of redo catheter procedures was higher in the CA arm than the HA arm (n=15 vs. n=3, P=0.021). The total number of SAEs was low and did not differ between groups (HA: n=6 vs. CA: n=7, P=0.989). Moreover, QOL measured by the EHRA AF-symptom score improved for both groups post-procedure (3.2±0.7 and 1.6±0.78, P<0.001) and were better for HA than CA after 3 years (1.3±0.7 and 1.9±0.8, P=0.029). Conclusion After three years, (thoracoscopic) HA continues to have superior rhythm outcomes compared to CA with a comparable long-term safety profile. While both procedures resulted in a reduction in AF symptoms, EHRA scores were more favorably scored by patients in the HA arm. Therefore, in experienced centers thoracoscopic HA should be considered as a first-line treatment to percutaneous approaches for ablation-naive patients with persistent AF.Figure 1Table 1

Reversible acute heart failure induced by thyrotoxic cardiomyopathy: A case report.

Thyrotoxic cardiomyopathy is a rare but severe complication of thyrotoxicosis, leading to episodes of acute heart failure. This case report highlights a rare presentation of thyrotoxic cardiomyopathy with low-output heart failure, emphasizing the importance of early diagnosis and comprehensive management. The report aims to increase awareness among clinicians about the potential reversibility of this condition and the effective strategies for managing such complex cases. This patient presented with dyspnea and chest constriction, without any antecedent predisposing factors. Subsequently, the patient abruptly manifested symptoms indicative of acute heart failure during outpatient consultation. Electrocardiography revealed rapid atrial fibrillation with type A preexcitation syndrome, whereas cardiac ultrasonography demonstrated global cardiac enlargement with a diminished ejection fraction (EF). After a comprehensive evaluation, the patient was diagnosed with thyrotoxic cardiomyopathy, acute heart failure, and atrial fibrillation with preexcitation syndrome. Immediate interventions comprised diuretic administration, oxygen therapy, and antiarrhythmic agents, addressing acute heart failure concomitant with preexcitation syndrome. Following a fortnight of comprehensive therapeutic measures, the patient was discharged with a prescription for oral medications, notably methimazole. Following the intervention, the patient showed significant improvement with the resolution of heart failure symptoms and dyspnea, restoration of sinus rhythm, improved left ventricular ejection fraction (LVEF improved from 36% to 45%), and normalization of thyroid function. These outcomes underscore the efficacy of the intervention strategy and offer a hopeful prognosis for similar cases. Thyrotoxicosis may cause cardiomyopathy in patients with heart failure that manifests as dilated cardiac chambers. Clinicians should carefully screen patients for this reversible condition. Diagnosis requires a comprehensive assessment of various tests, and the therapeutic goal is to restore normal thyroid function.

Evolution of the ECG in idiopathic ventricular fibrillation survivors: results from a single-centre UK registry

Abstract Background Idiopathic ventricular fibrillation (VF) is a diagnosis of exclusion in subjects with an unexplained cardiac arrest and no evidence of overt structural or electrical cardiac abnormalities (1). It can be associated with an early repolarisation pattern (ERP)(2). Data on the evolution of the ECG in this population are lacking. Purpose To compare the baseline ECG characteristic of idiopathic VF survivors and age and gender matched controls, and investigate if the presence of an ERP at ECG is a predictor of risk. Methods Forty-nine subjects with idiopathic VF evaluated in our tertiary centre from 1997 to 2022, and followed-up for at least 3 months were included in this study. The first representative ECG available after cardiac arrest was evaluated and compared with that of an age and gender matched control with no symptoms, family history of sudden cardiac death and normal cardiac tests; moreover, comparison was made with a follow-up ECG off antiarrhythmic medications (quinidine, amiodarone and verapamil). Medical notes were reviewed to investigate the presence of events at f-up (SCD/appropriate ICD shock). Results The mean age at presentation was 33±7 years; 63% of patients were males, and 16% had previous syncope. Twelve cases (24%) and 6 controls (12%) showed ERP on the resting ECG (P=NS). Only resting heart rate (HR) and QRS duration differed between the two groups (Table 1). Follow-up ECGs in 46 idiopathic VF survivors indicated that resting HR, QRS axis and QTc values were significantly different compared to the baseline ECG. In addition, 4 subjects with ERP at baseline did not exhibit it on the most recent ECG, and 6 subjects without ERP at baseline showed it on the most recent ECG. Over a median follow-up of 3.3 years (IQR 6), 13 subjects experienced appropriate ICD shocks. Kaplan-Meyer survival estimates showed no differences in events between subjects showing ERP or not (log rank p=0.092). Conclusions Subjects with idiopathic VF show baseline ECGs similar to those of age and gender matched healthy controls from the general population. ECG parameters tend to change only slightly over long-term follow up. The ERP in idiopathic VF survivors is dynamic and thus its relationship with events may be underestimated.Table 1 Table 2

Ablation of anomalous mitral annular pathways via transradial access: early hospital discharge due to the covid-19 pandemic

Abstract Introduction Wolff-Parkinson-White (WPW) syndrome arises from the conduction through accessory pathways (AP) connecting the atria and ventricles, bypassing the atrioventricular node. Radiofrequency catheter ablation of AP is the recommended treatment, often performed via transradial access. This approach is widely utilized in percutaneous coronary intervention due to its safety, effectiveness, patient preference, cost-effectiveness, and simplicity. Our study aims to present the results of AP ablation in the mitral annulus through transradial access amid the Covid-19 pandemic, marked by hospital bed scarcity and the need for early discharge. Materials and Methods Between May 2020 and December 2021, eight cases of transradial AP ablation in the mitral annulus were conducted. The service had previously achieved success in 16 transradial ablation cases. Among the eight cases during the pandemic, 62.5% were male, aged 24 to 56 years, all experiencing tachycardic palpitations and pre-syncope with a history of hospitalization. In 25% of cases, syncope episodes occurred. Patients were on propafenone, with no structural heart disease. Covid-19 tests were negative. Radial and ulnar artery perfusion integrity was assessed using the Allen maneuver and arterial Doppler. The right radial artery was used in 100% of cases. Sixty-two point five percent of accessory pathways were in anterolateral positions, and 37.5% were left posteroseptal. The approach was through the right radial artery, under local anesthesia, with venous sedation, using a 7Fr introducer sheath and positioning of the explorer catheter. Mapping was conducted during sinus rhythm, and adenosine IV tests followed ablation. The catheter was removed, and a pneumatic local dressing was applied for 2 hours, followed by a conventional dressing change for 24 hours. Results Ablation was successful in all eight patients. The procedure time ranged from 40 to 80 minutes, with an average of 55 minutes. Two to four radiofrequency applications were applied for a total of 2 minutes, using 55 W energy and a temperature of 55 to 60°C. No complications occurred during or after the procedure. Patients were discharged three hours post-intervention. Follow-up included reviews every four months, ECGs without ventricular pre-excitation, asymptomatic patients without antiarrhythmic medication, and no complications at the puncture site one year post-procedure. Conclusion Although based on a small sample of eight cases, and acknowledging the need for a larger sample to establish the procedure as an alternative, considering possible operator experience influence, we conclude that radial access proved effective and safe in this patient group. Its usage was exceptional, specifically in the context of a pandemic with crowded hospitals. Selection criteria and comparisons with other alternatives should be adopted for analyzing its potential future use.Transradial approachAblation catheter in the mitral plane

Use of class IC antiarrhythmic drugs in patients with structural heart disease and implantable cardioverter defibrillator

Abstract Background Due to suspected pro-arrhythmic effects and increased mortality associated with class-IC antiarrhythmic drugs (AADs) in previous trials, AAD-therapy in structural heart disease (SHD) is mainly restricted to amiodarone. In the presence of diagnostic and therapeutic advancements in cardiovascular medicine, it remains unclear if previous studies adequately reflect contemporary patients. In clinical practice, class-IC-AADs are occasionally used in individual cases, particularly in patients with an implantable cardioverter defibrillator (ICD). Methods This study retrospectively investigated outcome in ICD-carriers with SHD in whom class-IC-AADs were used as an individualized therapy due to failure, side effects, or unacceptable risk of alternative therapeutic options. Results Fifty patients from four tertiary centers were included (median age 48.5 years; 52% female). The most common underlying SHD were dilated (42%) or ischemic cardiomyopathy (26%) (median LVEF=45%). Indications for AAD were sustained ventricular arrhythmias (VA) (58%), symptomatic premature ventricular contractions (26%), or atrial arrhythmias (16%). Median follow-up was 27.8 months. Freedom from sustained VA was 72%, freedom from ICD-therapy was 80%. In 19 patients (38%) AAD-therapy was terminated. The most common reason was insufficient efficacy (n=8). Pro-arrhythmia was suspected in three patients. Five patients died during follow-up (10.0%), two of cardiovascular cause (4.0%). Conclusion In a multicenter cohort of ICD-carriers with SHD, class-IC-AADs were associated with a low rate of pro-arrhythmic effects or cardiovascular mortality. The majority of patients remained free from sustained VA during a follow-up of >2 years. Further efforts should be made to evaluate the safety of class-IC-AADs in SHD-patients receiving contemporary cardiovascular therapy.