Abstract 11668: High Resolution Magnetocardiography as a Novel Noninvasive Tool to Distinguish Between Benign and Malignant Early Repolarization Pattern
Introduction: Most of the early repolarization patterns (ERP) in electrocardiography (ECG) are benign but some of them are associated with ventricular fibrillation (VF).
We evaluated whether or not a high spatio-temporal resolution magnetocardiography (MCG) could non-invasively detect malignant types of ERP.
Methods: Sixty four-channel MCG, standard 12-lead ECG, and signal averaged ECG (SAECG) were recorded in 120 patients with inferolateral ERP in ECG without any major structural heart diseases; 13 of them had a history of VF (VF(+)-group) and the remaining 107 had no VF (VF(-)-group). We evaluated the following novel MCG indexes: MCG-QRS (msec), root mean square of terminal 40 msec magnetic field (MCG-RMS) (msec), and the duration under 10% of maximal amplitude (MCG-LAS) (msec) of the highest amplitude channel.
Results: The amplitude and distribution of the J-wave, ST-T morphology in ECG, parameters of SAECG were not significantly different, whereas MCG-QRS and MCG-LAS were significantly longer and MCG-RMS was smaller in ERP-VF(+) compared with ERP-VF(-) group (107(SD=24) vs 84(13) msec, P<0.01, 8(22) vs 22(11) msec, P<0.01, 0.10(0.08) vs 0.28(0.19) msec, P<0.01, respectively). In the multivariate logistic regression model, only MCG-QRS remained significant among the MCG indexes and the existing predictors (odds ratio (OR) 1.08, 95%CI 1.01 to1.17). The predictive ability of VF was significantly higher using MCG-QRS when the c-statistic was compared with that of the existing ECG measure (0.82 vs 0.56, P<0.01, Figure). When cut-offs were set by the least squares method at MCG-QRS 100 msec, MCG-RMS 0.24 msec, MCG-LAS 27 msec, corresponding ORs were calculated as 12.7, 95%CI 3.6 to 45.0, 6.1, 95%CI 1.7 to 21.2, 6.2, 95%CI 1.8 to 20.8, respectively.
Conclusions: MCG-QRS >100 msec was a simple and effective criterion for prediction of high risk ERP subjects, thus MCG analysis is an useful screening tool to detect malignant ERP out of the numerous benign ones.
Author Disclosures: N. Iwakami: None. T. Aiba: None. H. Takaki: None. T. Kamakura: None. M. Wada: None. K. Ishibashi: None. I. Nakajima: None. K. Miyamoto: None. Y.Y. Inoue: None. H. Okamura: None. S. Nagase: None. T. Noda: None. K. Kusano: None. S. Yasuda: Research Grant; Modest; Takeda, Otsuka, Bristol-Myers, Boehringer Ingel. Speakers Bureau; Modest; Takeda, Daiichi-Sankyo, Astra-Zeneca, Bristol-Myers. H. Ogawa: Other Research Support; Modest; Astellas Pharma Inc, Bristol-Myers Squibb Company, Chugai Pharmaceutical Co, Ltd., Dainippon Sumitomo Pharma Co., Ltd., MSD K.K., Mochida Pharmaceutical Co., Ltd., Ono Pharmaceutical Co., Ltd., Otsuka, Pfizer Japan Inc, Takeda Pharmaceutical Co., Ltd.. Other Research Support; Significant; Bayer, Daiichi Sankyo Co., Ltd., Novartis Pharma K.K.. Honoraria; Modest; AstraZeneca K.K., Boehringer Ingelheim Japan, Bristol-Myers Squibb Company, Mitsubishi Tanabe Pharma, Pfizer Japan Inc, Sanofi K.K., Teijin Pharma Co., Ltd. Honoraria; Significant; Bayer Yakuhin, Ltd., Daiichi Sankyo Co., Ltd., MSD K.K., Takeda Pharmaceutical Co., Ltd.. M. Sugimachi: None. S. Kamakura: None.
- © 2015 by American Heart Association, Inc.