Predictors of electrical storm in patients with idiopathic dilated cardiomyopathy--how to stratify the risk of electrical storm.
BACKGROUND
Electrical storm (ES) is a serious problem in patients with an implantable cardioverter defibrillator (ICD). However, insufficient reports have indicated the predictors of ES in ICD patients with idiopathic dilated cardiomyopathy (DCM). The purpose of this study was to clarify the predictors of ES for risk stratification in DCM patients with an ICD.


RESULTS
Of 446 ICD patients, 53 DCM patients were included in this study. During a mean follow-up of 55+/-36 months, ES (> or =3 times appropriate ICD therapy within 24 h) occurred in 18/53 (34%) patients. According to multivariate Cox proportional hazard regression analysis, a duration of the terminal low amplitude signals of <40 microV (LAS40) (HR 1.4/10 ms increase, 95% confidence interval (CI) 1.1-2.1; P=0.0049) or root mean square voltage of the last 40 ms of the QRS complex (RMS40) (HR 0.88/1 microV, 95%CI 0.77-0.96; P=0.001) on the signal averaged electrocardiogram, and a history of atrial fibrillation (AF) before ICD implantation (HR 2.3, 95%CI 1.2-5.0; P=0.013) were independently associated with an increased risk of ES.


CONCLUSIONS
Our data indicated that a longer LAS40, lower RMS40 and history of AF before ICD implantation could strongly predict ES, and the combination of those parameters could effectively stratify the risk of ES in DCM patients.
Takigawa
Masateru
M
Division of Cardiology, Department of Internal Medicine, National Cardiovascular Center, Suita, Japan.
Noda
Takashi
T
Kurita
Takashi
T
Aihara
Naohiko
N
Yamada
Yuko
Y
Okamura
Hideo
H
Satomi
Kazuhiro
K
Suyama
Kazuhiro
K
Shimizu
Wataru
W
Kamakura
Shiro
S
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation; D002311:Cardiomyopathy, Dilated / Q000150:complications* / Q000628:therapy; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D018570:Risk Assessment