[Left bundle branch stimulation in diffuse electrical heart disease in a pediatric patient]. / Estimulación de rama izquierda en enfermedad eléctrica difusa cardiaca en una paciente pediátrica.

Left bundle branch stimulation is a second-line strategy in patients where His bundle stimulation is not optimal. Currently, no cases of left bundle branch stimulation have been reported in patients with diffuse electrical cardiac disease or in the pediatric population.

Acute and long-term success of ventricular tachycardia ablation in patients with ischemic heart disease in a Mexican center.

Objective: . To report the results of ventricular tachycardia (VT) catheter ablation in ischemic heart disease (IHD), and to identify risk factors associated with recurrence in a Mexican center. Materials and methods: . We made a retrospective review of the cases of VT ablation performed in our center from 2015 to 2022. We analyzed the characteristics of the patients and those of the procedures separately and we determined factors associated with recurrence. Results: . Fifty procedures were performed in 38 patients (84% male; mean age 58.1 years). Acute success rate was 82%, with a 28% of recurrences. Female sex (OR 3.33, IC 95% 1.66-6.68, p=0.006), atrial fibrillation (OR 3.5, IC 95% 2.08-5.9, p=0.012), electrical storm (OR 2.4, IC 95% 1.06-5.41, p=0.045), functional class greater than II (OR 2.86, IC 95% 1.34-6.10, p=0.018) were risk factors for recurrence and the presence of clinical VT at the time of ablation (OR 0.29, IC 95% 0.12-0.70, p=0.004) and the use of more than 2 techniques for mapping (OR 0.64, IC 95% 0.48-0.86, p=0.013) were protective factors. Conclusions: . Ablation of ventricular tachycardia in ischemic heart disease has had good results in our center. The recurrence is similar to that reported by other authors and there are some factors associated with it.

Impact of the coronavirus disease-19 pandemic on electrophysiological procedures at a national referral center.

INTRODUCTION: The coronavirus disease (COVID-19) pandemic has generated serious repercussions on the health system, reducing the number of all cardiology procedures worldwide. OBJECTIVES: Describe the impact of the COVID-19 pandemic on the procedures performed by the electrophysiology department in a national referral center. METHODS: We made a retrospective review of our data base and we compared procedures made in the past 3 years since 2017-2019 with the procedures made in the 2020. We divided the procedures into two large groups: Cardiac Implantable Electronic Devices (CIED) related procedures and electrophysiological procedures (EP) which included conventional and complex ablations. RESULTS: There was a significant reduction in all the procedures, the average of procedures performed in the last 3 previous years was 467, while in 2020, we performed only 319 (p = 0.01); this represents a reduction of 33.4% in the total number of procedures. There was no statistical difference regarding the CIED related procedures, the average of procedures in the past 3 previous years was 174, and in 2020 we performed 190 procedures (p = 0.46). Regarding the EP, the average of the past 3 previous years was 293, while in 2020, we performed only 129 procedures (p < 0.01). The reduction in the EP was 55.97%. The most affected months were April, May, and June. CONCLUSIONS: The COVID-19 pandemic considerably affected the number of the procedures in our center, reducing it by 33.4%. The reduction of procedures fundamentally affected the ablations, with a reduction of 55.97%. The number of CIED related procedures was not affected.

Epicardial ablation of incessant left atrial appendage tachycardia in a case with tachycardiomyopathy.

Atrial tachycardias originated at the left atrial appendage (LAA) are uncommon; often they are incessant and might induce tachycardiomyopathy, as discussed by Hillock et al. (Heart Rhythm;3(4):467-469, 2006). A case of a 21-year-old woman with incessant atrial tachycardia is presented, refractory to medical therapy, echocardiography showed global dilation with LV ejection fraction of 20%. After two failed endocardial ablations, an epicardial access was attempted. The earliest activation site was located at the tip of the epicardial aspect of the LAA. RFCA was successful at this site. The patient remains asymptomatic during a follow-up of 10 months; the ventricular function was completely recovered after 6 months (LVEF of 50%).

Atrialized right ventricular chamber as a source of ventricular tachycardia in Ebstein's anomaly. Analysis of two successful catheter ablation cases.

Ventricular tachycardia in Ebstein's anomaly patients is rare and increases the risk of sudden death up to 6 times. We present two cases of Ebstein's anomaly, the first of them with a history of Glenn surgery and biological prosthesis at tricuspid position and the second case without surgical repair. Both admitted to the emergency room due to ventricular tachycardia poorly tolerated. Detailed substrate characterization and pace mapping showed fragmented signals in the area of atrialized right ventricle and correlated were pace mapping reproduced morphology identical to the clinical VT, ablation at this sites were successful without recurrence during follow-up.

Out-of-hospital cardiac arrest due to idiopathic ventricular fibrillation in patients with normal electrocardiograms: results from a multicentre long-term registry.

AIMS: To define the clinical characteristics and long-term clinical outcomes of a large cohort of patients with idiopathic ventricular fibrillation (IVF) and normal 12-lead electrocardiograms (ECGs). METHODS AND RESULTS: Patients with ventricular fibrillation as the presenting rhythm, normal baseline, and follow-up ECGs with no signs of cardiac channelopathy including early repolarization or atrioventricular conduction abnormalities, and without structural heart disease were included in a registry. A total of 245 patients (median age: 38 years; males 59%) were recruited from 25 centres. An implantable cardioverter-defibrillator (ICD) was implanted in 226 patients (92%), while 18 patients (8%) were treated with drug therapy only. Over a median follow-up of 63 months (interquartile range: 25-110 months), 12 patients died (5%); in four of them (1.6%) the lethal event was of cardiac origin. Patients treated with antiarrhythmic drugs only had a higher rate of cardiovascular death compared to patients who received an ICD (16% vs. 0.4%, P = 0.001). Fifty-two patients (21%) experienced an arrhythmic recurrence. Age ≤16 years at the time of the first ventricular arrhythmia was the only predictor of arrhythmic recurrence on multivariable analysis [hazard ratio (HR) 0.41, 95% confidence interval (CI) 0.18-0.92; P = 0.03]. CONCLUSION: Patients with IVF and persistently normal ECGs frequently have arrhythmic recurrences, but a good prognosis when treated with an ICD. Children are a category of IVF patients at higher risk of arrhythmic recurrences.

Role of the burden of premature atrial contractions during the blanking period following second-generation cryoballoon ablation in predicting late recurrences of atrial arrhythmias.

PURPOSE: Recent data suggests that high burden of premature atrial complexes after pulmonary vein isolation predicts recurrences of atrial arrhythmias. The present study sought to assess the role of premature atrial complexes burden in predicting atrial arrhythmias recurrences in patients with atrial fibrillation (AF) who have undergone second-generation cryoballoon ablation (CB-Adv). METHODS: Consecutive patients with drug-resistant paroxysmal atrial fibrillation who underwent pulmonary vein isolation using CB-Adv technology as the index procedure were retrospectively included. Twenty-four-hour Holter recordings were performed for every patient. Based on previously published data, a burden of more than 76 premature atrial complexes per day was considered as being high. RESULTS: One hundred and seven patients were included in the analysis. The recurrence rate among the group of patients with more than 76 premature atrial complexes per day was significantly higher compared with the group with a lower burden of premature atrial complexes (47.5 vs 11.9%, respectively; p < 0.001). In the multivariate analysis, the documentation of more than 76 premature atrial complexes per day registered at 1 month and at the end of the blanking period, predicted late recurrence of atrial arrhythmias. CONCLUSIONS: Frequent premature atrial complexes in the early stages after CB-Adv ablation strongly predict late recurrences of atrial arrhythmias.

Long-Term Trends in Newly Diagnosed Brugada Syndrome: Implications for Risk Stratification.

BACKGROUND: A proband of Brugada syndrome (BrS) is the first patient diagnosed in a family. There are no data regarding this specific, high-risk population. OBJECTIVES: This study sought to investigate the Brugada probands diagnosed from 1986 through the next 28 years. METHODS: We included 447 probands belonging to families with a diagnostic type 1 electrocardiogram Brugada pattern. The database was divided into 2 periods: the first period identified patients who were part of the initial cohort that became the consensus document on BrS in 2002 (early group); the second period reflected patients first diagnosed from 2003 to January 2014 (latter group). RESULTS: There were 165 probands in the early group and 282 in the latter group. Aborted sudden death as the first manifestation of the disease occurred in 12.1% of the early group versus 4.6% of the latter group (p = 0.005). Inducibility during programmed electrical stimulation was achieved in 34.4% and 19.2% of patients, respectively (p < 0.001). A spontaneous type 1 electrocardiogram pattern at diagnosis was present in 50.3% early versus 26.2% latter patients (p = 0.0002). Early group patients had a higher probability of a recurrent arrhythmia during follow-up (19%) than those of the latter group (5%) (p = 0.007). The clinical suspicion and use of a sodium-channel blocker to unmask BrS has allowed earlier diagnoses in many patients. CONCLUSIONS: Since being first described, the presentation of BrS has changed. There has been a decrease in aborted sudden cardiac death as the first manifestation of the disease among patients who were more recently diagnosed. These variations in initial presentation have important clinical consequences. In this setting, the value of inducibility to stratify individuals with BrS has changed.

Crioablación: aplicaciones clínicas en la electrofisiología cardiaca a partir de sus bases biofísicas / Cryoablation: Clinical applications in cardiac electrophysiology from their biophysical bases

Resumen: La crioablación es una energía alternativa a la radiofrecuencia para la ablación de diferentes arritmias, en la que sus propiedades biofísicas únicas ofrecen un perfil de seguridad mayor. Desde su utilización para el tratamiento quirúrgico de diversas arritmias hasta su conceptualización en la técnica transcatéter actual, la crioablación ha probado no solo ser una fuente segura de energía, sino una fuente eficaz a largo plazo. Mientras que la radiofrecuencia ha sido la energía más utilizada para el aislamiento de venas pulmonares en la ablación de fibrilación auricular, los avances tecnológicos con criobalón han logrado simplificar el procedimiento sin sacrificar su eficacia. La crioablación ha sido ampliamente utilizada para arritmias localizadas en sitios de alto riesgo, como la ablación de la taquicardia por reentrada intranodal AV y vías accesorias septales por su nulo riesgo teórico de bloqueo AV completo. Esta revisión tiene la intención de dar a conocer las aplicaciones clínicas de la criotermia a través del entendimiento profundo de sus bases biofísicas.

Abstract: Cryoablation is an energy alternative to radiofrequency for ablation of various arrhythmias, where its unique biophysical properties offer a greater safety profile. Since its first use for the surgical treatment of different arrhythmias until its conceptualization in the current technical transcatheter, cryoablation has proven not to be only a safe source of energy, but also an effective source in the long-term. While the radiofrequency has been the energy most used for isolation of pulmonary veins in atrial fibrillation ablation, technological advances in cryoballon have managed to simplify the procedure without sacrificing its effectiveness. Cryoablation has been widely used for arrhythmias located in high-risk locations, such as the ablation of the atrioventricular nodal reentrant tachycardia and septal accessory pathways, due to its theoretical null risk of complete AV block. This review intends to give the clinical applications of the cryothermy through a thorough understanding of their biophysical basis.

[Cryoablation: Clinical applications in cardiac electrophysiology from their biophysical bases]. / Crioablación: aplicaciones clínicas en la electrofisiología cardiaca a partir de sus bases biofísicas.

Cryoablation is an energy alternative to radiofrequency for ablation of various arrhythmias, where its unique biophysical properties offer a greater safety profile. Since its first use for the surgical treatment of different arrhythmias until its conceptualization in the current technical transcatheter, cryoablation has proven not to be only a safe source of energy, but also an effective source in the long-term. While the radiofrequency has been the energy most used for isolation of pulmonary veins in atrial fibrillation ablation, technological advances in cryoballon have managed to simplify the procedure without sacrificing its effectiveness. Cryoablation has been widely used for arrhythmias located in high-risk locations, such as the ablation of the atrioventricular nodal reentrant tachycardia and septal accessory pathways, due to its theoretical null risk of complete AV block. This review intends to give the clinical applications of the cryothermy through a thorough understanding of their biophysical basis.

Implantable cardioverter-defibrillator therapy in Brugada syndrome: a 20-year single-center experience.

BACKGROUND: Patients with Brugada syndrome and aborted sudden cardiac death or syncope have higher risks for ventricular arrhythmias (VAs) and should undergo implantable cardioverter-defibrillator (ICD) placement. Device-based management of asymptomatic patients is controversial. ICD therapy is associated with high rates of inappropriate shocks and device-related complications. OBJECTIVES: The objective of this study was to investigate clinical features, management, and long-term follow-up of ICD therapy in patients with Brugada syndrome. METHODS: Patients presenting with spontaneous or drug-induced Brugada type 1 electrocardiographic findings, who underwent ICD implantation and continuous follow-up at a single institution, were eligible for this study. RESULTS: A total of 176 consecutive patients were included. During a mean follow-up period of 83.8 ± 57.3 months, spontaneous sustained VAs occurred in 30 patients (17%). Eight patients (4.5%) died. Appropriate ICD shocks occurred in 28 patients (15.9%), and 33 patients (18.7%) had inappropriate shocks. Electrical storm occurred in 4 subjects (2.3%). Twenty-eight patients (15.9%) experienced device-related complications. In multivariate Cox regression analysis, aborted sudden cardiac death and VA inducibility on electrophysiologic studies were independent predictors of appropriate shock occurrence. CONCLUSIONS: ICD therapy was an effective strategy in Brugada syndrome, treating potentially lethal arrhythmias in 17% of patients during long-term follow-up. Appropriate shocks were significantly associated with the presence of aborted sudden cardiac death but also occurred in 13% of asymptomatic patients. Risk stratification by electrophysiologic study may identify asymptomatic patients at risk for arrhythmic events and could be helpful in investigating syncope not related to VAs. ICD placement is frequently associated with device-related complications, and rates of inappropriate shocks remain high regardless of careful device programming.

Periprocedural outcomes of prophylactic protamine administration for reversal of heparin after cryoballoon ablation of atrial fibrillation.

PURPOSE: The aim of this study was to investigate the efficacy and the safety of prophylactic use of protamine in a series of heparinized patients having undergone cryoballoon (CB) ablation for atrial fibrillation (AF). METHODS: From October 2013 to January 2014, 54 consecutive patients received protamine after CB ablation to neutralize unfractionated heparin (UFH) effects. They were prospectively included in this study and compared to a control group of 53 patients who underwent CB ablation without receiving protamine. RESULTS: A total of 54 consecutive patients (33 male, 61%; mean age, 58 ± 12 years) were included. Twenty-one patients (39%) presented with hypertension, 17 (31%) with dyslipidemia, and 4 (7%) with diabetes. Five patients (9%) had a previous episode of ischemic stroke. Mean protamine dose was 68 ± 22 mg. No adverse reaction to protamine was observed. Among patients having received protamine, one (2%) experienced a cardiac tamponade requiring non-surgical drainage. No patient having undergone protamine administration experienced vascular complications. Conversely, the group of patients not treated with protamine had a significantly higher incidence of vascular complications as compared to patients having undergone protamine infusion (11 vs 0%, p = 0.01). CONCLUSIONS: Reversing effects of UFH by the means of protamine administration appears to be safe after CB ablation for AF. It can allow in-laboratory sheath removal with potentially less vascular complications and no increase of thromboembolic risk. Larger randomized studies are needed in order to confirm our findings.

Drug-induced brugada syndrome in children: clinical features, device-based management, and long-term follow-up.

OBJECTIVES: The goal of this study was to investigate the clinical features, management, and long-term follow-up of children with drug-induced Brugada syndrome (BS). BACKGROUND: Patients with BS <12 years of age with a spontaneous type I electrocardiogram have a higher risk of arrhythmic events. Data on drug-induced BS in patients <12 years of age are lacking. METHODS: Among 505 patients with ajmaline-induced BS, subjects ≤12 years of age at the time of diagnosis were considered as children and eligible for this study. RESULTS: Forty children (60% male; age 8 ± 2.8 years) were included. Twenty-four children (60%) had a family history of sudden death. Two (5%) had a previous episode of aborted sudden death, and 8 (20%) had syncope. Children experienced more frequent episodes of sinus node dysfunction (SND) compared with older subjects (7.5% vs. 1.5%; p = 0.04) and had a comparable incidence of atrial tachyarrhythmias. Children more frequently experienced episodes of ajmaline-induced sustained ventricular arrhythmias (VAs) compared with older patients (10.0% vs. 1.3%; p = 0.005). Twelve children (30%) received an implantable cardioverter-defibrillator (ICD). After a mean follow-up time of 83 ± 51 months, none of the children died suddenly. Spontaneous sustained VAs were documented in 1 child (2%). Among children with ICD, 1 (8%) experienced an appropriate shock, 4 (33%) had inappropriate ICD shocks, and 4 (33%) experienced device-related complications. CONCLUSIONS: Drug-induced BS is associated with atrial arrhythmias and SND. Children are at higher risk of ajmaline-induced VAs. The rate of device-related complications, leading to lead replacement or inappropriate shocks, is considerable and even higher than with appropriate interventions. Based on these findings, the optimal management of BS in childhood should remain individualized, taking into consideration the patient's clinical history and family's wishes.

The clinical significance of pregnancy in Brugada syndrome.

INTRODUCTION AND OBJECTIVES: Little is known about the risks and outcomes of pregnancy in women with Brugada syndrome. We therefore evaluated pregnancy outcomes and the influence of pregnancy in patients with Brugada syndrome. METHODS: A retrospective analysis was performed in all pregnant women with Brugada syndrome. We included 104 women with a total of 219 deliveries. RESULTS: There were 15 spontaneous abortions. One infant died suddenly during the night 3 months after birth. Six pregnant women reported they had experienced at least 1 syncope during the pregnancy. Of the 3 women who received an implantable cardioverter-defibrillator before the pregnancy, none received arrhythmia episodes. There were no events during the pregnancy in 4 patients with a previously aborted sudden cardiac death. Of 24 patients with syncope when not pregnant, 18 were asymptomatic and 6 experienced a recurrent syncope during the pregnancy. During the follow-up (mean follow-up 298.9 days; 95% confidence interval, 289.6-308.2), 2 women received appropriate shocks. CONCLUSIONS: In this retrospective, single-center study, serious events were not more frequent during pregnancy and the peripartum period in women with Brugada syndrome. The occurrence of syncope during pregnancy was not associated with a worst outcome in the peri- and postpartum periods or during follow-up. The reported rate of miscarriage and sudden infant death will require further studies to confirm or rule out its association with Brugada syndrome.

One-year follow-up after single procedure Cryoballoon ablation: a comparison between the first and second generation balloon.

BACKGROUND: With respect to the first generation Cryoballoon (CB), the second generation (Cryoballoon Advance [CB-A], Medtronic, Minneapolis, MN, USA) was designed with technical modifications resulting in a larger and more uniform zone of freezing on the balloon's surface aiming at procedural outcome improvement in the setting of atrial fibrillation (AF) ablation. However, a comparison between both technologies on a midterm follow-up is missing in today's literature. METHODS: A total of 100 patients (the last 50 patients with the first generation CB and the first 50 patients with the second generation CB-A upon its inception in our center) having undergone a single CB ablation for paroxysmal AF (PAF) and having completed a 12-month follow-up, were consecutively included in our study. Freedom from AF off-antiarrhythmic drugs (AADs) after a single procedure was 78% (39/50) in CB-A and 58% (29/50) in the CB group (P = 0.03) during the whole follow-up duration. Considering a blanking period of 3 months, freedom from AF off-AAD was achieved in 84% (42/50) in CB-A, while 66% (33/50) were free from recurrence in the CB group (P = 0.038). Right phrenic nerve palsy (PNP) occurred in 8 patients (16%) in CB-A group and in 4 patients (8%) in the CB group. CONCLUSION: Freedom from AF on 12 months follow-up was significantly higher in the CB-A group with respect to the first generation device. The most frequent complication observed was PNP.

Prevalence and electrocardiographic characteristics of early repolarization pattern in young teen athletes.

INTRODUCTION: Early repolarization (ERP) is a common electrocardiographic finding. Its potential to cause cardiac arrhythmias has been hypothesized from experimental studies, but it is not known whether there is a clinical association with sudden cardiac arrest. METHODS: 122 subjects (100% males; mean age: 13.5 +/- 2.7 years) were included from a local youth soccer team in Belgium. All subjects underwent physical examination and a 12-lead ECG was taken. The main objective of the study was to evaluate early repolarization patterns and to determine its prevalence. RESULTS: Of the 122 included subjects, 1 subject with Coumel tachycardia was excluded.The overall prevalence of ERP in our study population was 36%, with 9.1% in the inferior leads, 8.2% in the lateral leads and 18.2% both leads. A family history of sudden cardiac death (SCD) was not higher in the group of ERP (N=3; 6.8%) compared to the non-ERP group (N = 4; 5.2%) (P = 0.713). Interestingly, incomplete right bundle-branch block (IRBBB) was significantly lower among all subjects with ERP (N = 15; 34.1%), compared to those without ERP (N = 49; 63%) (P < 0.002). CONCLUSION: ERP is a common finding in young teen athletes. In this population global ERP (both inferior and lateral) is more common than isolated inferior or lateral ERP. Young age might be a contributing factor in causing a more diffuse repolarization abnormality.