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Background Purkinje ectopics (PurkEs) are major triggers of idiopathic ventricular fibrillation (VF). Identifying clinical factors associated with specific PurkE characteristics could yield insights into the mechanisms of Purkinje-mediated arrhythmogenicity. Objective The purpose of this study was to examine the associations of clinical, environmental, and genetic factors with PurkE origin in patients with PurkE-initiated idiopathic VF. Methods Consecutive patients with PurkE-initiated idiopathic VF from 4 arrhythmia referral centers were included. We evaluated demographic characteristics, medical history, clinical circumstances associated with index VF events, and electrophysiological characteristics of PurkEs. An electrophysiology study was performed in most patients to confirm the Purkinje origin. Results Eighty-three patients were included (mean age 38 ± 14 years; 44 [53%] women), of whom 32 had a history of syncope. Forty-four patients had VF at rest. PurkEs originated from the right ventricle (RV) in 41 patients (49%), from the left ventricle (LV) in 36 (44%), and from both ventricles in 6 (7%). Seasonal and circadian distributions of VF episodes were similar according to PurkE origin. The clinical characteristics of patients with RV vs LV PurkE origins were similar, except for sex. RV PurkEs were more frequent in men than in women (76% vs 24%), whereas LV and biventricular PurkEs were more frequent in women (81% vs 19% and 83% vs 17%, respectively) (P Conclusion PurkEs triggering idiopathic VF originate dominantly from the RV in men and from the LV or both ventricles in women, adding to other sex-related arrhythmias such as Brugada syndrome or long QT syndrome. Sex-based factors influencing Purkinje arrhythmogenicity warrant investigation.

Syncope in patients with an early repolarization (ER) pattern presents a challenge for clinicians as it has been identified as an indicator of a higher risk of life-threatening ventricular arrhythmias (VAs).This study aimed to analyze the outcome of patients with an ER pattern and syncope and to evaluate the factors predictive of VAs.Over a period of 5 years, we enrolled 143 patients with an ER pattern and syncope in a multicenter prospective registry.After the initial examinations, 97 patients (67.8%) were implanted with a device allowing electrocardiogram monitoring, including 84 (58.7%) with an implantable loop recorder. During a mean follow-up period of 68 ± 34 months, we documented 16 arrhythmias presumably responsible for syncope (5 VAs, 10 bradycardias, and 1 supraventricular tachycardia). Additionally, recurrent syncope not associated with electrocardiogram documentation occurred in 16 patients (11.2%). The cause of syncope was identified in 23 of 97 patients with a monitoring device (23.8%). The 5-year incidence of VAs and arrhythmic events presumably responsible for syncope was 4.9% and 11.0%, respectively. Patients who developed VAs showed no prodromes or specific triggers at the time of syncope. Neither the presence of a family history of sudden cardiac death nor the previously reported high-risk electrocardiographic parameters differed between patients with and without VAs.VAs occurred in 4.9% of patients with an ER pattern and syncope. Device implantation based on detailed history taking seems to be a reasonable strategy. Previously reported high-risk electrocardiographic patterns did not identify patients with VAs.

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

Inferolateral early repolarization (ER) is highly prevalent and is associated with idiopathic ventricular fibrillation (VF).The purpose of this study was to evaluate the potential role of T-wave parameters to differentiate between malignant and benign ER.We compared the ECGs of patients with ER and VF (n = 92) with control subjects with asymptomatic ER (n = 247). We assessed J-wave amplitude, QTc interval, T-wave/R-wave (T/R) ratio in leads II and V5, and presence of low-amplitude T waves (T-wave amplitude0.1 mV and10% of R-wave amplitude in lead I, II, or V4-V6).Compared to controls, the VF group had longer QTc intervals (388 ms vs. 377 ms, P = .001), higher J-wave amplitudes (0.23 mV vs. 0.17 mV, P.001), higher prevalence of low-amplitude T waves (29% vs. 3%, P.001), and lower T/R ratio (0.18 vs. 0.30, P.001). Logistic regression analysis demonstrated that QTc interval (odds ratio [OR] per 10 ms: 1.15, 95% confidence interval [CI} 1.02-1.30), maximal J-wave amplitude (OR per 0.1 mV: 1.68, 95% CI 1.23-2.31), lower T/R ratio (OR per 0.1 unit: 0.62, 95% CI 0.47-0.81), presence of low-amplitude T waves (OR 3.53, 95% CI 1.26-9.88). and presence of J waves in the inferior leads (OR 2.58, 95% CI 1.18-5.65) were associated with malignant ER.Patients with malignant ER have a higher prevalence of low-amplitude T waves, lower T/R ratio (lead II or V5), and longer QTc interval. The combination of these parameters with J-wave amplitude and distribution of J waves may allow for improved identification of malignant ER.

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, SCOPUS: ar.j, info:eu-repo/semantics/published

BACKGROUND: Detailed information on the profile of patients with Brugada syndrome (BrS) presenting their first arrhythmic event (AE) after prophylactic implantation of an implantable cardioverter-defibrillator (ICD) is limited. OBJECTIVES: The objectives of this study were (1) to compare clinical, electrocardiographic, electrophysiologic, and genetic profiles of patients who exhibited their first documented AE as aborted cardiac arrest (group A) with profiles of those in whom the AE was documented after prophylactic ICD implantation (group B) and (2) to characterize group B patients' profile using the class II indications for ICD implantation established by HRS/EHRA/APHRS expert consensus statement in 2013. METHODS: A survey of 23 centers from 10 Western and 4 Asian countries enabled data collection of 678 patients with BrS who exhibited their AE (group A, n = 426; group B, n = 252). RESULTS: The first AE occurred in group B patients 6.7 years later than in group A (mean age 46.1 ± 13.3 years vs 39.4 ± 15.1 years; P < .001). Group B patients had a higher incidence of family history of sudden cardiac death and SCN5A mutations. Of the 252 group B patients, 189 (75%) complied with the HRS/EHRA/APHRS indications whereas the remaining 63 (25%) did not. CONCLUSION: Patients with BrS with the first AE documented after prophylactic ICD implantation exhibited their AE at a later age with a higher incidence of positive family history of sudden cardiac death and SCN5A mutations as compared with those presenting with aborted cardiac arrest. Only 75% of patients who exhibited an AE after receiving a prophylactic ICD complied with the 2013 class II indications, suggesting that efforts are still required for improving risk stratification.

Background A growing body of evidence suggests that the arrhythmogenic substrate underlying Brugada syndrome (BrS) is located in the right ventricular outflow tract (RVOT), and electrophysiological abnormalities recently evidenced most commonly concur in conduction slowing. Also, imaging studies reported wall motion abnormalities of the RVOT in patients with BrS, with a various extent of RV remodeling. However, there are no data regarding a potential relationship between electrophysiological alterations and contraction abnormalities in BrS. Objective We aimed to assess (1) the potential relationship between contraction delays of the RV quantified by phase analysis of equilibrium radionuclide angiography (ERNA), and the spontaneous ST-segment elevation pattern; and (2) to evidence RV remodeling in patients with BrS. Methods Seventy patients with BrS and 18 control subjects were included in the study. For the purpose of the study, the spontaneous ST-segment elevation pattern was graded simultaneously to ERNA acquisition. RV contraction delays and amplitude were assessed using multiharmonic phase analysis of ERNA, and ventricular volumes and ejection fraction were assessed using gated blood-pool single photon emission computed tomography. Results RVOT contraction was delayed in patients with BrS, and RV contraction heterogeneity increased according to the pattern of ST-segment elevation, without impairment of the amplitude of contraction. RV volumes were greater in patients with BrS compared with control subjects, without impairment of the ejection fraction, whatever the ST-segment elevation pattern or the magnitude of contraction heterogeneity. Conclusion In patients with BrS, we found a relationship between RV contraction heterogeneity and ST-segment pattern, providing evidence of a functional modulation of the arrhythmogenic substrate.

Background Para-Hisian pacing is an effective method of differentiating between pathways for retrograde conduction over the accessory pathway (AP) and over the atrioventricular node (AVN). When performing para-Hisian pacing, the pacing spike sometimes captures only the His bundle, which we named "pure" Hisian pacing (Hc). Objective We evaluated the significance of pure Hisian pacing for predicting the pathways of ventriculoatrial conduction. Methods In 62 patients with supraventricular tachycardia, both para-Hisian and pure Hisian pacing were carried out during the sinus rhythm, resulting in three different types of electrocardiographic complexes with wide (local ventricular myocardial capture), slightly narrow (both local myocardial and His bundle capture), and very narrow QRS widths (Hc). A change of atrial activation sequence as demonstrated by these pacing modes indicated the presence of multiple retrograde pathways. The diagnosis of retrograde pathways by para-Hisian pacing with or without Hc was evaluated. Results In 22 patients with AVN reentrant tachycardia, para-Hisian pacing alone was able to correctly predict ventriculo-atrial conduction exclusively through the AVN without requiring findings from Hc. In 40 AP patients, para-Hisian pacing showed a pattern of retrograde conduction through the AVN in six, through both the AVN and AP in 10, and through an AP in 24 patients. Four of these 24 patients were diagnosed as having multiple pathways (AP+AVN or dual APs) by the addition of Hc. Conclusion Pure Hisian pacing can help disclose another pathway for retrograde conduction in AP patients, which is unpredicted by ordinary para-Hisian pacing.

ST segment elevation in the right precordial leads constitutes the electrocardiogram (ECG) hallmark of Brugada syndrome (BS). This pattern is variable and can be concealed, but the magnitude and the cause of ST segment fluctuations have been poorly investigated.Our goal was to quantify ST changes and to assess rate and autonomic influences on ST level.A 12-lead ECG was continuously recorded during 24 hours in 20 patients with BS (ages 49 +/- 12) and 10 healthy subjects (ages 32 +/- 7). Using two-dimensional binning we obtained average QRS-T complexes every 30 minutes (time bins) and at different RR intervals (rate bins) for each subject. ST level was measured at five different points located 90, 100, 110, 120, and 140 ms after Q onset (Qo). In BS patients, the highest ST elevation was measured 110 ms after Qo (Qo+110).ST level changes between time points were significantly greater in patients with BS compared with control subjects: on lead V2, the range of ST level at Qo+110 was 264 +/- 85 microV in BS and 91 +/- 22 microV in control subjects (P.01). In BS, ST level decreased with heart rate acceleration: the difference in ST level at Qo+110 for RR = 900 and 600 ms was 55 +/- 53 microV (P.01). HFnu was positively, although weakly, correlated with ST level (R(2) = 0.02, P.01).ECG changes observed in patients with BS are related in part to heart rate influences on ST segment level. These spontaneous fluctuations over a 24-hour time period suggest that Holter recordings may improve the ECG diagnosis sensitivity in BS.