Inferolateral Early Repolarization Research Articles

New observations on the “early repolarization syndrome”

They described a highprevalence of this electrocardiographic (ECG) pattern (de-fined as J-point elevation [JPE]) in idiopathic VF, thusseeming to confirm previous hypotheses. From a clinicalpoint of view, this new evidence forced us to look for thispattern in subjects classified until then as idiopathic VF. Atthe same time, it is necessary to establish the “reverseassociation”: that is, are healthy individuals with this pat-tern, without any other risk factor, at risk for sudden cardiacdeath (SCD)? This turns out to be a major clinical dilemmadue to the high prevalence of this pattern in the normalpopulation, and this was the subject of an excellent recentreview.

Impact of Infero/Lateral Early Repolarization Pattern in Patients with Brugada Syndrome

Background: Inferolateral early repolarization (ER) pattern is often observed in Brugada syndrome (BrS). However, its clinical implication in this syndrome is still controversial. Method: Total two-hundred forty five Brugada ECG patients (mean age 48 years, men/female=235⁄10), including documented ventricular fibrillation (VF) in 27, were evaluated. Infero/lateral ER pattern was defined as a notched or slurring>1 mm J-wave at least consecutive two of inferior (II, III, aVF) or lateral (I, aVL, V4, V5, V6) leads. The presence of this ER pattern was compared with clinical, electrocardiographic and genetic parameters. Results: Infero/lateral ER pattern was observed in 25 (10.2%) BrS patients (inferior leads in 12, lateral leads in 11 and both in 2) and was significantly associated with patients of documented VF (P 120 ms), family history of sudden death, positive late potential on signal averaged ECG and SCN5A mutation. Increased number of positive ER leads have a trend of increasing documented VF patients (>3 leads; 54%). Conclusion: These data indicates that infero/lateral ER reflects the expansion of repolarization abnormality in the ventricle and may be associated with high-risk phenotype in BrS.

Early Repolarization Is a Risk Marker of Ventricular Fibrillation and Prognosis in Anterior Acute Myocardial Infarction

Background: In patients without structural heart disease, the presence of early repolarization on ECG is associated with ventricular fibrillation (VF). However, it is unclear the correlation between early repolarization and VF in patients with acute myocardial infarction (AMI). Methods: We studied 162 patients with first-anterior-acute-ST-elevation MI received percutaneous coronary intervention, and evaluated ECG after successful reperfusion. Early repolarization was defined as an elevation of the QRS-ST junction of >0.1 mV from baseline in the inferior or lateral lead. VF was defined as that not terminated spontaneously and required electrical cardioversion. Patients were classified into two groups (VF group and non-VF group). Results: VF occurred in 22 patients (13.6%). Early repolarization was present in 47 of the 162 patients (29%). The prevalence of early repolarization was significantly higher (54.5% vs. 25%; p 2 (β-coefficient 0.31 (95%CI; 0.179 to 0.448), p<0.01) and early repolarization (β-coefficient 0.18 (95%CI; 0.074 to 0.289), p<0.01). Conclusions: Despite degree of initial TIMI flow grade, the presence of infero-lateral early repolarization may be a potential risk factor for VF leading to poor prognosis in anterior AMI patients.

Inferolateral early repolarization in athletes

Early repolarization (ER) has been considered a common benign ECG pattern among young athletes. In contrast, an inferolateral early repolarization pattern has been associated with an increased risk for sudden cardiac death (SCD). The aim of the study was to assess the prevalence of inferolateral ER among young collegiate athletes and to describe the characteristics associated to the pattern. We analyzed ECGs from 503 athletes (51% males; age range, 17-24). Information on gender, body weight, race, sport, and family history of SCD was collected. ER was defined as a slow deflection of the down slope of the R wave (≥0.1mV) or positive wave at J point (≥0.1mV) in two consecutive inferior or in lateral leads. Additionally, we included voltage measurements according to the Sokolow-Lyon criteria and RR interval measurement. The prevalence of ER was 30% (inferior, 20%; lateral, 21%; both, 11%). Male gender (59% vs. 48%, p = 0.019), left ventricular hypertrophy (LVH) voltage (39% vs. 12%, p < 0.001) was significantly associated with the ER pattern. In addition, there was a trend towards longer RR interval in the inferior ER group (p = 0.06) and there were slightly more African-Americans with ER compared to non-African-American (34% vs. 28%, p = 0.22). Among females (p = 0.039) and African-Americans (p = NS), the association of LVH to ER was not as strong. ER is a common finding among young athletes. The ECG marker of LVH is the dominant shared characteristic among the athletes with ER, along with male gender and a trend to greater prevalence among African-American athletes.

HIGH FREQUENCY OF ELECTROCARDIOGRAPHIC ABNORMALITIES AT EARLY REPOLARIZATION PHASE IN IDIOPATHIC VENTRICULAR FIBRILLATION

Abstract Category: Clinical Electrophysiology--Ventricular ArrhythmiasPresentation Number: 1133-124Authors: Yuka Hayashi, Hiroshi Watanabe, Kazuki Okamura, Masahito Sato, Yukio Hosaka, Hiroshi Furushima, Masaomi Chinushi, Hirotaka Oda, Masaaki Okabe, Yoshifusa Aizawa, Division of Cardiology, Niigata University School of Medicine, Niigata, Japan, Niigata Idiopathic Ventricular Fibrillation Study Group, Niigata, Japan Background: Recently, we and others have reported that inferolateral early repolarization is associated with idiopathic ventricular fibrillation. However, idiopathic ventricular fibrillation is a heterogeneous disease and there may be other ECG abnormalities associated with fatal arrhythmias. Here, we studied electrocardiographic (ECG) characteristics and outcome in idiopathic ventricular fibrillation.Methods: We included 30 patients with idiopathic ventricular fibrillation (7 females, 46 ± 22 years) and 150 age- and sex-matched controls. Patients were excluded if they had Brugada syndrome, or short or long QT intervals. All patients had arrhythmic events, 4 patients (13%) had family history of sudden death, and 12 patients (71%) had inducible ventricular fibrillation by electrical stimulation.Results: PR interval was longer in patients with idiopathic ventricular fibrillation than controls, while heart rate, QRS duration, and QT interval were similar between two groups. Early repolarization in the inferolateral leads was more common in patients with idiopathic ventricular fibrillation (n=13, 57%) than controls (n=17, 13%). Early repolarization in the right precordial leads, which was different from type I Brugada ECG, was also more common in patients with idiopathic ventricular fibrillation (n=8, 27%) than controls (n=1, 1%) and flecainide challenge was negative in all of the patients with idiopathic ventricular fibrillation. Premature ventricular beats showing QRS consignation of left bundle branch block with inferior axis triggered arrhythmias in 4 patients. During a follow up of 4.8 ± 4.5 years, arrhythmia recurred in 10 patients (33%) with idiopathic ventricular fibrillation. Early repolarization accentuated at the events in 56% of patients with idiopathic ventricular fibrillation, although the frequency of recurrences was not different between patients with early repolarization and those without.Conclusions: ECG abnormalities at the early repolarization phase were found in most of patients with idiopathic ventricular fibrillation, suggesting an important role of the abnormalities for increased electrical vulnerability to ventricular fibrillation.

Long-Term Prognosis of Probands With Brugada-Pattern ST-Elevation in Leads V 1 –V 3

Background— The prognosis of patients with saddleback or noncoved type (non–type 1) ST-elevation in Brugada syndrome is unknown. The purpose of this study was to clarify the long-term prognosis of probands with non–type 1 ECG and those with coved (type 1) Brugada-pattern ECG. Methods and Results— A total of 330 (123 symptomatic, 207 asymptomatic) probands with a coved or saddleback ST-elevation ≥1 mm in leads V 1 –V 3 were divided into 2 ECG groups—type 1 (245 probands) and non–type 1 (85 probands)—and were prospectively followed for 48.7�15.0 months. The absence of type 1 ECG was confirmed by drug provocation test and multiple recordings. The ratio of individuals with a family history of sudden cardiac death (14%) was lower than previous studies. Clinical profiles and outcomes were not notably different between the 2 groups (annual arrhythmic event rate of probands with ventricular fibrillation; type 1: 10.2%, non–type 1: 10.6%, probands with syncope; type 1: 0.6%, non–type 1: 1.2%, and asymptomatic probands; type 1: 0.5%, non–type 1: 0%). Family history of sudden cardiac death at age &lt;45 years and coexistence of inferolateral early repolarization with Brugada-pattern ECG were independent predictors of fatal arrhythmic events (hazard ratio, 3.28; 95% confidence interval, 1.42 to 7.60; P =0.005; hazard ratio, 2.66; 95% confidence interval, 1.06 to 6.71; P =0.03, respectively, by multivariate analysis), although spontaneous type 1 ECG and ventricular fibrillation inducibility by electrophysiological study were not reliable parameters. Conclusions— The long-term prognosis of probands in non–type 1 group was similar to that of type 1 group. Family history of sudden cardiac death and the presence of early repolarization were predictors of poor outcome in this study, which included only probands with Brugada-pattern ST-elevation.

Characteristics of Recurrent Ventricular Fibrillation Associated With Inferolateral Early Repolarization: Role of Drug Therapy

Our purpose was to evaluate the efficacy of antiarrhythmic drugs (AADs) in recurrent ventricular fibrillation (VF) associated with inferolateral early repolarization pattern on the electrocardiogram. Although an implantable cardioverter-defibrillator is the treatment of choice, additional AADs may be necessary to prevent frequent episodes of VF and reduce implantable cardioverter-defibrillator shock burden or as a lifesaving therapy in electrical storms. From a multicenter cohort of 122 patients (90 male subjects, age 37 +/- 12 years) with idiopathic VF and early repolarization abnormality in the inferolateral leads, we selected all patients with more than 3 episodes of VF (multiple) including those with electrical storms (> or =3 VF in 24 h). The choice of AAD was decided by individual physicians. Follow-up data were obtained for all patients using monitoring with implantable defibrillator. Successful oral AAD was defined as elimination of all recurrences of VF with a minimal follow-up period of 12 months. Multiple episodes of VF were observed in 33 (27%) patients. Electrical storms (34 +/- 47 episodes) occurred in 16 and were unresponsive to beta-blockers (11 of 11), lidocaine/mexiletine (9 of 9), and verapamil (3 of 3), while amiodarone was partially effective (3 of 10). In contrast, isoproterenol infusion immediately suppressed electrical storms in 7 of 7 patients. Over a follow-up of 69 +/- 58 months, oral AADs were poorly effective in preventing recurrent VF: beta-blockers (2 of 16), verapamil (0 of 4), mexiletine (0 of 4), amiodarone (1 of 7), and class 1C AADs (2 of 9). Quinidine was successful in 9 of 9 patients, decreasing recurrent VF from 33 +/- 35 episodes to nil for 25 +/- 18 months. In addition, quinidine restored a normal electrocardiogram. Multiple recurrences of VF occurred in 27% of patients with early repolarization abnormality and may be life threatening. Isoproterenol in acute cases and quinidine in chronic cases are effective AADs.