Search

Background: There is limited information on ethnic differences between patients with Brugada syndrome (BrS) and arrhythmic events (AEs).Objective: The purpose of this study was to compare clinical, electrocardiographic (ECG), electrophysiological, and genetic characteristics between white and Asian patients with BrS and AEs.Methods: The Survey on Arrhythmic Events in Brugada Syndrome is a multicenter survey from Western and Asian countries, gathering 678 patients with BrS and first documented AE. After excluding patients with other (n = 14 [2.1%]) or unknown (n = 30 [4.4%]) ethnicity, 364 (53.7%) whites and 270 (39.8%) Asians comprised the study group.Results: There was no difference in AE age onset (41.3 ± 16.1 years in whites vs 43.3 ± 12.3 years in Asians; P = .285). Higher proportions of whites were observed in pediatric and elderly populations. Asians were predominantly men (98.1% vs 85.7% in whites; P < .001) and frequently presented with aborted cardiac arrest (71.1% vs 56%; P < .001). Asians tended to display more spontaneous type 1 BrS-ECG pattern (71.5% vs 64.3%; P = .068). A family history of sudden cardiac death was noted more in whites (29.1% vs 11.5%; P < .001), with a higher rate of SCN5A mutation carriers (40.1% vs 13.2% in Asians; P < .001), as well as more fever-related AEs (8.5% vs 2.9%; P = .011). No difference was observed between the 2 groups regarding history of syncope and ventricular arrhythmia inducibility.Conclusion: There are important differences between Asian and white patients with BrS. Asian patients present almost exclusively as male adults, more often with aborted cardiac arrest and spontaneous type 1 BrS-ECG. However, they have less family history of sudden cardiac death and markedly lower SCN5A mutation rates. The striking difference in SCN5A mutation rates should be tested in future studies. [ABSTRACT FROM AUTHOR]

Background: There is limited information on gender differences in patients with Brugada syndrome (BrS) who experienced arrhythmic events (AEs).Objective: The purpose of this study was to compare clinical, electrocardiographic (ECG), electrophysiological, and genetic characteristics between males and females in patients with BrS with their first AE.Methods: The multicenter Survey on Arrhythmic Events in BRUgada Syndrome collected data on the first AE in 678 patients with BrS including 619 males (91.3%) and 59 females (8.7%) aged 0.27-84 years (mean age 42.5 ± 14.1 years) at the time of AE occurrence.Results: After excluding pediatric patients, it was found that females were older than males (49.5 ± 14.4 years vs 43 ± 12.7 years, respectively; P = .001). Higher proportions of females were observed in the pediatric and elderly populations. In Asians, the male to female ratio for AEs was ≈9-fold higher than that in White. Spontaneous type 1 BrS ECG was associated with an earlier onset of AEs in pediatric females. A similar prevalence (≈65%) of spontaneous type 1 BrS ECG was present in males and females above the age of 60 years. Females less frequently showed spontaneous type 1 BrS ECG (41% vs 69%; P < .001) or arrhythmia inducibility at electrophysiology study (36% vs 66%; P < .001). An SCN5A mutation was more frequently found in females (48% vs 28% in males; P = .007).Conclusion: This study confirms that female patients with BrS are much rarer, display less type 1 Brugada ECG, and exhibit lower inducibility rates than do males. It shows for the first time that female patients with BrS with AE have higher SCN5A mutation rates as well as the relationship between gender vs age at the onset of AEs and ethnicity. [ABSTRACT FROM AUTHOR]

Background: The literature on fever-related arrhythmic events (AEs) in Brugada syndrome (BrS) is currently limited to few case reports and small series.Objective: The present study aimed to describe the characteristics of fever-related AE in a large cohort of patients with BrS.Methods: The Survey on Arrhythmic Events in Brugada Syndrome is a multicenter study on 678 patients with BrS with first AE documented at the time of aborted cardiac arrest (n = 426) or after prophylactic implantable cardioverter-defibrillator implantation (n = 252).Results: In 35 of 588 patients (6%) with available information, the AE occurred during a febrile illness. Most of the 35 patients were male (80%), Caucasian (83%), and proband (70%). The mean age at the time of AE was 29 ± 24 years (range 0.3-76 years). Most patients (80%) presented with aborted cardiac arrest and 6 (17%) with arrhythmic storm. Family history of sudden death, history of syncope, and spontaneous type 1 Brugada electrocardiogram were noted in 17%, 40%, and 71% of patients, respectively. Ventricular fibrillation was induced at electrophysiology study in 9 of 19 patients (47%). An SCN5A mutation was found in 14 of 28 patients (50%). The highest proportion of fever-related AE was observed in the pediatric population (age <16 years), with a disproportionally higher event rate in the very young (age 0-5 years) (65%). Males were involved in all age groups and females only in the pediatric and elderly groups. Fever-related AE affected 17 Caucasians aged <24 years, but no Asians aged <24 years.Conclusion: The risk of fever-related AE in BrS markedly varies according to age group, sex, and ethnicity. Taking these factors into account could help the clinical management of patients with BrS with fever. [ABSTRACT FROM AUTHOR]

Verapamil-sensitive left fascicular monomorphic ventricular tachycardia (LF-VT) was first described ~4 decades ago. Our knowledge regarding this arrhythmia is evolving continuously. The current review aims to highlight up to date aspects of this arrhythmia focusing on its ECG recognition, new considerations of the reentrant circuit, ablation targets in inducible and non-inducible patients and the approach to LF-VT with multiform morphology. [ABSTRACT FROM AUTHOR]

Background: Left posterior fascicular ventricular tachycardia (LPF-VT) is frequently misdiagnosed as supraventricular tachycardia with aberrant right bundle branch block (RBBB) and left anterior hemiblock (LAHB). The purpose of the present study was to define the morphological ECG characteristics of LPF-VT and attempt to differentiate it from RBBB and LAHB aberrancy.Methods and Results: A systematic Medline search was used to identify or locate ECG tracings from patients with LPF-VTs. ECGs with LPF-VT were also collected from patients who underwent ablation of this arrhythmia at the Tel Aviv and Sheba Medical Centers. These ECGs were compared with ECGs of consecutive patients with RBBB and LAHB and no obvious cardiac pathology by echocardiography. Overall, 183 ECGs of LPF-VT were compared with 61 ECGs showing RBBB and LAHB. Univariate analysis demonstrated differences in QRS axis, limb (I, aVr), and precordial (V1, V2, V6) ECG leads. On multivariate logistic regression analysis, LPF-VT was more often associated with atypical RBBB-like V1 morphology (odds ratio, 5.1; P=0.004), positive QRS in aVr (odds ratio, 19.2; P<0.001), V6 R/S ratio ≤1 (odds ratio, 6.7; P=0.01), and QRS ≤140 ms (odds ratio, 7.7; P<0.001). Using these 4 variables, a prediction model was developed that predicted LPF-VT with sensitivity and specificity of 82.1% and 78.3%, respectively. Patients with 3 of 4 positive variables had high probability of having LPF-VT, whereas patients with ≤1 positive variable always had RBBB plus LAHB.Conclusions: The morphological ECG characteristics of LPF-VT were defined, and a high accurate tool for correctly differentiating LPF-VT from RBBB and LAHB aberrancy was developed. [ABSTRACT FROM AUTHOR]

Background: Atrioventricular nodal reentrant tachycardia (AVNRT) is considered a sporadic disease occurring in ≈22.5 cases per 10 000 in the general population. We define the prevalence and characteristics of familial AVNRT among patients who underwent radiofrequency ablation.Methods and Results: Ablation reports of all patients with familial AVNRT (at least 2 first-degree family members) who underwent radiofrequency ablation in our institution and in another hospital were reviewed. There were 1587 patients from our institution, of whom 20 had ≥1 first-degree relatives with AVNRT. This indicates a familial AVNRT prevalence of 127 cases per 10 000 (95% confidence interval, 82-196/10 000). First-degree relatives of patients with AVNRT presented a hazard ratio of at least 3.6 for exhibiting AVNRT compared with the general population. After inclusion of 4 families with familial AVNRT who underwent ablation at another hospital our population study comprised a total of 24 families (50 patients) with AVNRT. Patients at ablation were younger in the familial AVNRT group when compared with the sporadic AVNRT group (44.2±19 versus 54.8±18 years old, P=0.0001). The male/female ratio was similar, with female predominance. The supraventricular tachycardia mechanism was typical slow/fast reentry in most cases in both groups. The most common familial relationship in our 24 families included a parent and a child in 67% of cases and less often 2 siblings (29%).Conclusions: Familial AVNRT prevalence is higher than previously believed suggesting that this arrhythmia may have a genetic component. Autosomal dominance with incomplete penetrance is the most likely mode of inheritance. [ABSTRACT FROM AUTHOR]

Background: Information on long-term clinical outcome of patients with Brugada syndrome treated with electrophysiologically guided class 1A antiarrhythmic drugs (AAD) is limited.Methods and Results: An aggressive protocol of programmed ventricular stimulation was performed in 96 patients with Brugada syndrome (88% males; mean age, 39.8±15.9 years). Ten patients were cardiac arrest survivors, 27 had presented with syncope, and 59 were asymptomatic. Ventricular fibrillation was induced in 66 patients, including 100%, 74%, and 61% of patients with cardiac arrest, syncope, and no symptoms, respectively. All but 6 of the 66 patients with inducible ventricular fibrillation underwent electrophysiological testing on quinidine (n=54), disopyramide (n=2), or both (n=4). Fifty-four (90%) patients were electrophysiological responders to >1 AAD with similar efficacy rates (≈90%) in all patients groups. Patients with no inducible ventricular fibrillation at baseline were left on no therapy. After a mean follow-up of 113.3±71.5 months, 92 patients were alive, whereas 4 died from noncardiac causes. No arrhythmic event occurred during class 1A AAD therapy in any of electrophysiological drug responders and in patients with no baseline inducible ventricular fibrillation. Arrhythmic events occurred in only 2 cardiac arrest survivors treated with implantable cardioverter-defibrillator alone but did not recur on quinidine. All cases of recurrent syncope (n=12) were attributed to a vasovagal (n=10) or nonarrhythmic mechanism (n=2). Class 1A AAD therapy resulted in 38% incidence of side effects that resolved after drug discontinuation.Conclusions: Our data suggest that electrophysiologically guided class 1A AAD treatment has a place in our therapeutic armamentarium for all types of patients with Brugada syndrome. [ABSTRACT FROM AUTHOR]

Background: During radiofrequency (RF) ablation of paroxysmal atrial fibrillation, a circular multielectrode recording “lasso” catheter is generally positioned within each pulmonary vein (PV) to determine when pulmonary vein potentials (PVPs) are present and when they have been ablated. The new irrigated multipolar nMARQ circular ablation catheter is positioned within the left atrium to create contiguous circular ablation lines around each PV ostium. Objective: To determine whether the recordings obtained from the nMARQ catheter position around the PV ostium accurately reproduce the recordings obtained from a lasso catheter positioned within that vein. Methods: In 10 patients undergoing RF ablation of paroxysmal atrial fibrillation, we placed an nMARQ and a lasso catheter around and within each PV, respectively. Recordings obtained from both catheters at baseline and after RF ablation were compared. Results: At baseline, recordings of PVPs in both catheters were concordant in 92% of all PVs. However, after RF delivery, the concordance between the nMARQ and lasso recordings was poor. The discordant result most commonly observed was disappearance of “PVPs” from the nMARQ catheter with persistence of PVPs in the lasso catheter (12 of 39 [30%]). Conversely, the delivery of RF frequently resulted in fragmented electrograms (pseudo-PVPs) on the nMARQ catheter despite evidence of PV isolation by lasso catheter recordings. Conclusions: The use of an nMARQ catheter alone, as currently recommended, may lead to underestimation and overestimation of the number of RF applications required to achieve PV isolation. [Copyright &y& Elsevier]

Background: Epicardial ablation has been shown to be a useful adjunct for treatment of ventricular tachycardia (VT). Objective: To report the trends, safety, and efficacy of epicardial mapping and ablation at a single center over an 8-year period. Methods: Patients referred for VT ablation (June 2004 to July 2011) were divided into 3 groups: ischemic cardiomyopathy (ICM), nonischemic cardiomyopathy (NICM), and idiopathic ventricular arrhythmias (VA). Patients with scar-mediated VT who underwent combined epicardial and endocardial (epi-endo) mapping and ablation were compared with those who underwent endocardial-only (endo-only) ablation with regard to patient characteristics, acute procedural success, 6- and 12-month clinical outcomes. Results: Among 144 patients referred for VT ablation, 95 patients underwent 109 epicardial procedures (94% access rate). Major complications were seen in 8 patients (8.8%) with pericardial bleeding (>80 cm3) in 6 cases (6.7%), although no tamponade, surgical intervention, or procedural mortality was seen. Patients with ICM who underwent a combined epi-endo ablation had improved freedom from VT compared with those who underwent endo-only ablation at 12 months (85% vs 56%; P = .03). In patients with NICM, no differences were seen between those who underwent epi-endo ablation and those who underwent endo-only ablation at 12 months (36% vs 33%; P = 1.0). In idiopathic VA, only 2 of 17 patients were successfully ablated from the epicardium. Conclusions: In this large tertiary single-center experience, complication rates are acceptably low and improved clinical outcomes were associated with epi-endo ablation in patients with ICM. Patients with NICM represent a growing referred population, although clinical recurrence remains high despite epicardial ablation. Epicardial ablation has a low yield in idiopathic VA. [ABSTRACT FROM AUTHOR]

The article presents a study that hypothesized the role of recurrent ventricular tachycardia in improving scar substrates with multiple exit sites (MES) identified during pace-mapping. The study conducted high-density mapping in all subjects to delineate scar. Pace-mapping reveals the specificity of electrograms that exhibit MES and pace-mapped induction for sites critical to reentry.

Background: Prior chest surgery limits the ability to obtain epicardial access in patients referred for catheter ablation of ventricular tachycardia (VT). Objective: The purpose of this study was to describe the utility of different surgical approaches to access the epicardium for VT ablation. Methods: Clinical data of 14 patients with drug-refractory VT who underwent hybrid surgical epicardial access for catheter mapping and ablation in the electrophysiology lab were reviewed. Baseline patient and procedural characteristics including access, exposure, mapping techniques, and ablation were analyzed. Results: Of a total of 14 patients (age 63.2 ± 10.3 years), 11 had a subxiphoid window performed, and three patients underwent limited anterior thoracotomy to access the epicardium. The indication for surgical access was prior cardiac surgery (n = 12), previous failed epicardial access (n = 1), and ablation in close proximity to the coronary arteries and phrenic nerve (n = 1). Mapping in patients with subxiphoid surgical access was limited to the inferior and diaphragmatic surface of the heart extending posteriorly to the basal lateral wall. With limited anterior thoracotomy, access to the apex, anterior, and mid to apical anterolateral walls was obtained. In these regions, adhesions were more severe and repeat entry into the epicardial region at a different intercostal level was needed in two of three patients. Conclusion: Surgical access with subxiphoid window and limited anterior thoracotomy in the electrophysiology lab is feasible and safe. The surgical approach can be tailored to the region of interest in the ventricle to be mapped and ablated. [ABSTRACT FROM AUTHOR]

Background: Management of ventricular tachycardia (VT) in patients with hypertrophic cardiomyopathy (HCM) is challenging. Objective: The purpose of this study is to assess the value of radiofrequency catheter ablation (RFCA) for the treatment of the VTs in the setting of HCM. Methods: Twenty-two patients (18 with ICD) with HCM and multiple episodes of VTs resistant to medical therapy underwent RFCA with an open irrigation catheter. Epicardial access was obtained if required. All patients were followed for at least 1 year after RFCA. Results: Mean age was 50.4 ± 15.3, and mean ejection fraction was 34.3% ± 9.8%. RFCA was performed endocardially in all patients, while epicardial radiofrequency applications were needed in 13 patients. A previous endocardial ablation was unsuccessful in six patients. At 20 ± 9 months of follow-up, elimination of VTs reached 73%. No major complication was observed during and after the procedures in all patients. Conclusion: Catheter ablation of VTs in patients with hypertrophic cardiomyopathy refractory to medical therapy is safe, feasible, and successful in eliminating VT. Epicardial VT mapping and ablation should be considered as an important access option for the treatment of these patients to increase the success rate. [Copyright &y& Elsevier]

Background: Catheter ablation of the left atrium (LA) is associated with potential collateral injury to surrounding structures, especially the esophagus and the right phrenic nerve (PN). Objectives: The purpose of this study was to evaluate the efficacy and feasibility of intrapericardial balloon placement (IPBP) for the protection of collateral structures adjacent to the LA. Methods: Electroanatomic mapping was performed in porcine hearts using a transseptal endocardial approach in eight swine weighing 40–50 kg. An intrapericardial balloon was inflated in the oblique sinus, via percutaneous epicardial access, to displace the esophagus. Similarly, with the balloon positioned in the transverse sinus, IPBP was used to displace the right PN. Esophageal temperature was monitored while endocardial radiofrequency (RF) energy was delivered to the distal inferior PV. Results: In all cases, balloon placement was successful with no significant effects on hemodynamic function. Balloon inflation increased the distance between the esophagus and posterior LA by 12.3 ± 4.0 mm. IPBP significantly attenuated increases in luminal esophageal temperature during endocardial RF application (6.1 ± 2.4°C vs. 1.2 ± 1.1°C; P<.0001). High-output endocardial pacing from the right superior pulmonary vein ostium stimulated PN activity. After displacement of the right PN with IPBP, PN capture was abolished in 30 (91%) of 33 sites. Conclusions: These findings demonstrate that in an animal model, IPBP is feasible in the setting of catheter ablation procedures and has the potential to decrease the risk of collateral damage to the esophagus and PN during LA ablation. [Copyright &y& Elsevier]

Copyright of Heart - Edición Española is the property of Grupo ARS XXI de Comunicacion, S.A. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)