Spontaneous ECG Pattern Research Articles

ФЕНОМЕН ИЛИ СИНДРОМ БРУГАДА?

The Brugada syndrome (BrS) is an inherited disorder associated with increased risk of sudden cardiac death (SCD). Despite the rare occurrence of BrS, timely diagnosis and risk stratification are important tasks today. The presence of syncope of arrhythmic origin in conjunction with a spontaneous ECG pattern of BrS type 1 is a reliable indicator of a poor prognosis. Conversely, in the group with non-arrhythmic syncope, there is no increased risk of life-threatening ventricular tachyarrhythmias. However, the etiology of syncope is difficult to determine in 30% of cases. It is known that data obtained using implantable loop recorders can change therapy strategy in 20–36% of patients with BrS with unexplained syncope, what is a factor in stratifying the cardiac risk of sudden death in this group of patients. The article provides a brief overview of the medical literature and illustrates instances of the diagnosis of syncope in a patient with BrS. Modern approaches of diagnosis and treatment of BrS including catheter ablation and gene therapy are discussed. The clinical characteristics of the disease and the data of laboratory and instrumental studies of presented case are given.

How arrhythmic risk changes over time in patients with low risk Brugada syndrome

Abstract Background Brugada Syndrome (BrS) is an inherited disorder associated with an increased risk of sudden cardiac death (SCD) and is diagnosed by the presence of a Brugada type I ECG pattern, either spontaneous or drug-induced. A spontaneous ECG pattern is one of the two main risk factors for SCD, along with syncope. However, there is still no clear evidence on how and how often to screen patients with drug-induced BrS to detect a spontaneous ECG pattern, therefore allowing to reassess their arrhythmic risk. Purpose To determine how many subjects develop a spontaneous ECG pattern among a pool of patients with low risk BrS (drug-induced pattern without history of syncope at the time of diagnosis) observed through systematic ECG Holter monitoring. Methods We retrospectively collected data for all patients with low risk BrS treated at our center for at least 12 months between 2016 and 2021. Each patient was tested yearly with at least one 12-lead 24-hour ECG Holter monitoring with high precordial leads (V1-V2, V3-V4, V5-V6 respectively in 2nd, 3rd and 4th intercostal space parasternal left and right). In case of spontaneous pattern detection at two recordings, patients underwent electrophysiological study (EPS) and in case of inducible ventricular arrhythmias, implantable cardiac defibrillator (ICD) placement. Results We included 63 patients with low risk BrS. During a median follow-up of 48 months: 1 patient died for SCD (1.6%), 1 experienced syncope (1.6%) and 19 exhibited a spontaneous ECG pattern (30.2%). Of these 19 patients: 18 were males and 5 had a mutation of SCN5A; the average age at the time of spontaneous pattern detection was 48.1±11.5 years. The average number of ECG holters/per patient/per year was 1.1±0.6, the average number of ECG Holters until the detection of a spontaneous pattern was 3.3±1.8, whilst the average number of months in between the diagnosis and the detection of a spontaneous pattern was 43.2±41.1. After the observation of a spontaneous pattern: 6 patients were excluded from further investigation (as they had already undergone EPS or refused), 1 was directly treated with ICD and 12 underwent EPS, 4 of whom consequently underwent ICD placement. Among these 5 patients who underwent ICD placement – 7.9% of the original 63 patients – we observed 1 appropriate ICD intervention (antitachycardia pacing), 1 inappropriate ICD shock and 1 ICD related complication. Conclusions In our population of patients with low risk BrS the detection of a spontaneous ECG pattern is the most common determinant of risk reclassification. Systematic ECG Holter monitoring disclosed the presence of a spontaneous ECG pattern in a relevant number of subjects, allowing to reassess their arrhythmic risk and indication for ICD placement. Our study stresses the importance of periodic evaluation of low risk BrS patients with ECG Holter monitoring and the need for further investigation to define the optimal monitoring strategy. Funding Acknowledgement Type of funding sources: None.

P6585Number of ECG leads and prognosis of spontaneous type 1 Brugada syndrome

Abstract Introduction Brugada syndrome (BrS) is an inherited arrhythmia syndrome with an increased risk of sudden cardiac death (SCD). The recent single lead-based diagnosis of Brugada syndrome recommended criterion may lead to overdiagnosis of Brugada syndrome and overestimation of the risk of SCD. Objective We aim to investigate the value of a single lead diagnosis in spontaneous type 1 ECG Brugada patient and to investigate the association between the number of ECG leads with a spontaneous type 1 ST elevation and the arrhythmic risk. Methods Consecutive patients affected with BrS were recruited in a multicentric prospective registry in France (15 centers) between 1994 and 2016. A total of 1613 patients affected by the Brugada syndrome were enrolled. For this specific study, only patient with a spontaneous type 1 BrS were enrolled (n=505). Data were prospectively collected with an average follow-up of 6.5±4.7 years. ECGs were reviewed by 2 physicians blinded to clinical status. Type 1 ST elevation was defined by ≥2 mm J-point elevation with coved ST segment and negative T wave. Results A total of 505 patients with a spontaneous type 1 BrS (mean age 46±15 years, 398 males, 79%) were enrolled. 117 patients (23%) were symptomatic at baseline (32 (6%) aborted SCD, 85 (17%) syncope). Implantable cardiac defibrillator (ICD) was implanted in 191 patients (38%). Brugada ECG pattern was found in 1 lead in 250 patients (50%, group 1), in 2 leads in 227 patients (45%, group 2) and in 3 leads in 28 patients (5%, group 3). Groups were comparable in term of clinical presentation except for group 3 who presented more frequently an early repolarization pattern (n=19 (8%) in group 1, n=15 in group 2 (6%) and n=7 (25%) in group 3, p=0.02) and more frequently QRS fragmentation (n=6 (2%) in group 1, n=3 in group 2 (1%) and n=3 (11%) in group 3, p=0.03). During follow-up, 46 (9%) patients presented an arrhythmic event: 22 (9%) in group 1 (4 SCD, 14 appropriate ICD therapy, 4 ventricular arrhythmias), 22 (10%) in group 2 (6 SCD, 11 appropriate ICD therapy, 5 ventricular arrhythmias) and 2 (7%) in group 3 (1 SCD, 1 appropriate ICD therapy). Patients with type 1 BrS pattern in 2 or 3 ECG leads had not a significantly higher rate of arrhythmic events than patients with type 1 BrS pattern in only 1 ECG lead (HR: 1.1; 95% CI: 0.6–1.9 for group 2 and HR: 0.7; 95% CI: 0.2–3 for group 2; p=0,087). Conclusion In the largest cohort of BrS patients ever described, the prognosis of Brugada syndrome with a spontaneous ECG pattern does not appear to be affected by the number of leads required for diagnostic.

P5027Prognosis and evaluation of the risk markers of arrhythmia in a large population of Brugada syndrome patients

Abstract Introduction Brugada syndrome (BrS) is an inherited arrhythmia syndrome with an increased risk of sudden cardiac death (SCD) despite a structurally normal heart. Many parameters have been suggested to be associated with the risk of ventricular arrhythmias, but only previous symptoms and spontaneous ECG pattern have been consistently associated with the risk of ventricular arrhythmia occurrence. Objective The aim of this study was to evaluate the association of these parameters with arrhythmic events in the largest cohort of BrS patients ever described. Methods Consecutive patients affected with BrS were recruited in a multicentric prospective registry in France (15 centers) between 1994 and 2016. Data were prospectively collected with an average follow-up of 6.5±4.7 years. ECGs were reviewed by 2 physicians blinded to clinical status. Results In this study, we enrolled a total of 1613 patients (mean age 45±15 years; 1119 males, 69%). At baseline, 462 patients (29%) were symptomatic (51 (3%) aborted SCD, 257 (16%) syncope). A spontaneous type 1 ECG pattern was present in 505 patients (31%). Implantable cardiac defibrillator was implanted in 477 patients (30%). During the follow-up, 91 patients (6%) underwent arrhythmic events (16 SCD (10%), 48 appropriate ICD therapy (3%) and 27 ventricular arrhythmias (2%). Thirty-six patients (2%) died of non-arrhythmic causes. Mean age at the first event was 44±15 years. In our cohort, event predictors were SCD (HR: 18.3; 95% CI: 11.2–29.8; p<0.0001), syncope (HR: 2.9; 95% CI: 1.8–4.9; p<0.0001), age >60 years (HR: 0.11; 95% CI: 0.032–0.377; p=0,0004), gender (HR: 2.96; 95% CI: 1.6–5.4; p=0.0005), spontaneous type 1 (HR: 2.14; 95% CI: 1.42–3.23; p=0.0003), type 1 ST elevation in peripheral ECG lead (HR: 3.6; 95% CI: 1.9–7.1; p=0,0001), fragmented QRS (HR: 3.37; 95% CI: 1.37–8.32; p=0,008), AvR sign (HR: 2.2; 95% CI: 1.4–3.8; p=0,0007), QRS >120ms in D2 lead (HR: 2.2; 95% CI: 1.4–3.6; p=0,001) and QRS >90ms in V6 (HR: 2.1; 95% CI: 1.3–3.3; p=0,001). All the others parameters including early repolarization pattern (ERP) and EPS were not predictor of events. Conclusion In the largest cohort of BrS patients ever described, we confirmed that symptoms, age, gender, spontaneous type 1, type 1 ST elevation in peripheral ECG lead, fragmented QRS, AvR sign, QRS >120ms in D2 and QRS >90ms in V6 are associated with arrhythmic events whereas ERP and EPS were not.

Clinical presentation and follow-up of women affected by Brugada syndrome

Studies in Brugada syndrome (BrS) have mainly consisted of men. The purpose of this study was to describe the clinical characteristics and arrhythmic risk factors in BrS women. Consecutive BrS patients were enrolled from 1993 and followed prospectively. Among 1613 patients, 494 were women (mean age 47 ± 16 years). Women were more frequently asymptomatic than men (423 [86%] vs 867 [77%], respectively; P = .001) and less frequently had a spontaneous ECG pattern (107 [22%] vs 398 [36%], respectively; P <.001). During median [25th, 75th percentile] follow-up of 57 [23, 118] vs 62 [22, 113] months (P = .65), arrhythmic events occurred in 12 women (2%) vs 79 men (7%) (P= .0005). Mean age at the first event was 48.6 ± 17.8 years forwomen vs 43 ± 14.2 years for men (P <.001). Gender was significantly related to cardiac events (hazard ratio [HR] 2.96; 95% confidence interval [CI] 1.6-5.4; P = .0005). In multivariate analysis, event predictors in women were index patient status (HR 10.15; 95% CI 1.7-61.4; P = .01), previous sudden cardiac death (HR 69.4; 95% CI 15-312.5; P <.0001), syncope (HR 6.8; 95% CI 1.4-34.5; P = .02), fragmented QRS (HR 20.2; 95% CI 1.8-228.9; P = .02), and QRS duration >120 ms (HR 4.7; 95% CI 1.2-19.5; P = .03). Women represent a lower-risk group than men among individuals with BrS. In asymptomatic women, fragmented QRS and QRS >120 ms seem to be the only event predictors.

Clinical Presentation and Outcome of Brugada Syndrome Diagnosed With the New 2013 Criteria.

The 2013 HRS/EHRA/APHRS consensus statement recommends the use of V1 and V2 leads recorded in the second and third intercostal spaces (High-ICS) for diagnosis of Brugada syndrome (BrS) creating a new category of patients discovered only with modified leads. The clinical presentation and the arrhythmic risk in these patients are ill defined. This study was aimed at assessing the role of High-ICS in the analysis of BrS and the clinical profile of the patients diagnosed only when ECG leads are moved to upper intercostal spaces. We searched our Brugada syndrome registry and identified 300 subjects (age 36 ± 13 years), without a diagnostic coved ST-segment elevation in conventional V1 -V3 leads, both at baseline and after provocative drug challenge. Sixty-four subjects (21.3%, mean age at last follow-up 42 ± 11 years) were diagnosed with High-ICS. Diagnosis was possible at baseline only in 4 subjects while in 60 it was made after drug challenge with sodium channel blockers. Three subjects (4.7%) with spontaneous abnormal ECG experienced cardiac events with an annual event rate (0.11%) superimposable to that of the low risk category of BrS diagnosed in standard leads. This study demonstrates that the use of new diagnostic criteria for BrS allows increasing the diagnostic yield by 20% and that the arrhythmic risk is low when BrS can be established only in High-ICS. We also show that the prognostic value of spontaneous ECG pattern is confirmed in this subgroup.

0396: Sensitivity of sodium channel blocker in Brugada syndrome

Brugada syndrome (BS) is characterized by a typical ECG pattern. To carrying out the diagnosis in patients without a spontaneous ECG pattern, sodium channel blocker (SCB) is used. However, the value of this test is not well known, particulary its sensibility because of a complex genetic model do not allowing the use of any mutation as a gold standard. To clarify the value of this test, we analyzed a database of 680 SCB performed in families affected by the syndrome, considering the mandatory transmitters (MT) as a true positive. All patients who underwent a SCB and belonging to a family with at least 2 subjects with the syndrome were included. The MT was defined by an individual with at least one descendant in the first degree and an ascendant with a BS or unexplained sudden cardiac arrest. All the ECG data at baseline and at diagnosis was reviewed by two expert, blinded to the clinical and genetical status. Of the 137 selected families, 85 MT were identified. Excluding individuals who have not benefited from the SCB, sensitivity of test was calculated at 91% (42/46). According to the molecule used, the sensitivity was significantly better for ajmaline than flecainide with a sensitivity of 97% and 75% respectively (p =0.048). Among the 680 individuals who benefited a SBC, the duration of the S wave in DII, DIII and V5 and the R wave in aVR were significantly elongated at both baseline and diagnosis, in individuals with a positive SBC. Complications occurred in 1.6% of patients (11/680) including 4 required an electrical cardioversion. Risk factors present a complication was the youngest age and the occurrence of a complication with a member of his family. This study demonstrates for the first time, the excellent sensitivity of SCB in BS, particulary with the use of ajmaline. Complications are rare and doesn’t appeared to be linked with QRS enlargement but with familial history of ventricular arythmia during the test

192 Assessment of a relationship between functional and structural abnormalities in Brugada syndrome

Although Brugada syndrome (BrS) is a primarily electrical disease leading to conduction slowing, it is now acknowledged that structural alterations of the myocardium are frequently associated. Those two factors, may result in both contraction heterogeneity and remodeling of the right ventricle (RV). Radionuclide angiocardiography (RNA) with phase analysis is able to quantify contraction delays and to evaluate volumes and systolic function of ventricles. The aim of this study was to assess both functional and structural alterations of the RV in patients with BS and to investigate a relationship between them. Multiharmonic Fourier phase analysis of planar RNA was used to quantify contraction heterogeneity, and gated bloodpool SPECT to assess ventricular volumes and function in 71 patients with proven BrS [classified according to their spontaneous ECG pattern recorded just prior to ERNA as: concealed (n=26), type 2/3 (n=28), type 1 (n=17)] and 18 controls. RV contraction heterogeneity was greater in patients with BrS compared to controls (17.2±0.4° vs 15.1±0.7° respectively, p=0.007), and increased according to the repolarisation pattern from concealed forms to type 1 (ANOVA p=0.02). The increase of RV contraction heterogeneity was associated with an increased apex to RVOT contraction delay (r=0.4, p=0.006). RV end-diastolic and end-systolic volumes were greater in patients with BrS compared to controls (156±6 vs 134±7 ml, and 88±4 vs 73±4 ml respectively, p=0.02), to a similar proportion so as the ejection fraction was not significantly impaired (44±1% vs 45±2% respectively, p=0.4). Finally, there was no relationship between the magnitude of contraction heterogeneity and RV remodeling. The left ventricle was free of abnormality. In patients with BrS, RV contraction heterogeneity increases with the magnitude of repolarisation abnormalities, contrary to RV remodeling which is present to a mild extent whatever the repolarisation pattern.