Significance of electrocardiogram recording in high intercostal spaces in patients with early repolarization syndrome.
OBJECTIVE
Published reports regarding inferolateral early repolarization (ER) syndrome (ERS) before 2013 possibly included patients with Brugada-pattern electrocardiogram (BrP-ECG) recorded only in the high intercostal spaces (HICS). We investigated the significance of HICS ECG recording in ERS patients.


RESULTS
Fifty-six patients showing inferolateral ER in the standard ECG and spontaneous ventricular fibrillation (VF) not linked to structural heart disease underwent drug provocation tests by sodium channel blockade with right precordial ECG (V1-V3) recording in the 2nd-4th intercostal spaces. The prevalence and long-term outcome of ERS patients with and without BrP-ECG in HICS were investigated. After 18 patients showing type 1 BrP-ECG in the standard ECG were excluded, 38 patients (34 males, mean age; 40.4 ± 13.6 years) were classified into four groups [group A (n = 6;16%):patients with ER and type 1 BrP-ECG only in HICS, group B (n = 5;13%):ERS with non-type 1 BrP-ECG only in HICS, group C (n = 8;21%):ERS with non-type 1 BrP-ECG in the standard ECG, and group D (n = 19;50%):ERS only, spontaneously or after drug provocation test]. During follow-up of 110.0 ± 55.4 months, the rate of VF recurrence including electrical storm was significantly higher in groups A (4/6:67%), B (4/5:80%), and C (4/8:50%) compared with D (2/19:11%) (A, B, and C vs. D, P < 0.05).


CONCLUSIONS
Approximately 30% of the patients with ERS who had been diagnosed with the previous criteria showed BrP-ECG only in HICS. Ventricular fibrillation mostly recurred in patients showing BrP-ECG in any precordial lead including HICS; these comprised 50% of the ERS cohort.
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan Division of Cardiology, Department of Cardiovascular Medicine, Kyoto University, Kyoto, Japan.
Tsukasa
T
Kamakura
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan.
Mitsuru
M
Wada
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan.
Ikutaro
I
Nakajima
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan.
Kohei
K
Ishibashi
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan.
Koji
K
Miyamoto
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan.
Hideo
H
Okamura
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan.
Takashi
T
Noda
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan.
Takeshi
T
Aiba
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan.
Hiroshi
H
Takaki
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan.
Satoshi
S
Yasuda
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan.
Hisao
H
Ogawa
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan.
Wataru
W
Shimizu
Division of Cardiology, Department of Cardiovascular Medicine, Kyoto University, Kyoto, Japan.
Takeru
T
Makiyama
Division of Cardiology, Department of Cardiovascular Medicine, Kyoto University, Kyoto, Japan.
Takeshi
T
Kimura
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan kamakura@hsp.ncvc.go.jp.
Shiro
S
Kamakura
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita 565-8565, Japan.
Kengo
K
Kusano
D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D053840:Brugada Syndrome / Q000150:complications / Q000175:diagnosis; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D005260:Female; D005424:Flecainide / Q000494:pharmacology; D006801:Humans; D008012:Lidocaine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D011379:Prognosis; D012008:Recurrence; D018570:Risk Assessment; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000209:etiology*
D000889:Anti-Arrhythmia Agents; D008012:Lidocaine; C042288:pilsicainide; D005424:Flecainide
Brugada syndrome; Early repolarization; Electrocardiogram; High intercostal recording; Ventricular fibrillation