title: Early Myocardial Repolarization Heterogeneity Is Detected by Magnetocardiography in Diabetic Patients with Cardiovascular Risk Factors.
abstract: Multi-channel magnetocardiography (MCG) is a sensitive technique to map spatial ventricular repolarization with high resolution and reproducibility. Spatial ventricular repolarization heterogeneity measured by MCG has been shown to accurately detect and localize myocardial ischemia. Here, we explored whether these measurements correlated with cardiovascular risk factors in patients with type 2 diabetes. Two hundreds and seventy-seven type 2 diabetic patients without known coronary artery disease (CAD) and arrhythmia were recruited consecutively from the outpatient clinic of National Taiwan University Hospital. The spatially distributed QTc contour maps were constructed with 64-channel MCG using the superconducting quantum interference device (SQUID) system. Indices of myocardial repolarization heterogeneity including the smoothness index of QTc (SI-QTc) and QTc dispersion were derived and analyzed for association with conventional cardiovascular risk factors. SI-QTc correlated strongly with the QTc dispersion (r = 0.70, p <0.0001). SI-QTc was significantly higher in patients with presence of metabolic syndrome in comparison to those without metabolic syndrome (8.56 vs. 7.96 ms, p = 0.02). In univariate correlation analyses, QTc dispersion was associated with smoking status (average 79.90, 83.83, 86.51, and 86.00 ms for never smokers, ex-smokers, current smokers reporting less than 10 cigarettes daily, and current smoker reporting more than 10 cigarettes daily, respectively, p = 0.03), body weight (r = 0.15, p = 0.01), and hemoglobin A1c (r = 0.12, p = 0.04). In stepwise multivariate regression analyses, QTc dispersion was associated with smoking (p = 0.02), body weight (p = 0.04), total cholesterol levels (p = 0.05), and possibly estimated glomerular filtration rate (p = 0.07). In summary, spatial heterogeneity of myocardial repolarization measured by MCG is positively associated cardiovascular risk factors including adiposity, smoking, and total cholesterol levels.
authors.affiliation: Graduate Institute of Medical Genomics and Proteomics, National Taiwan University, Taipei, Taiwan; Department of Internal Medicine, National Taiwan University Hospital, HsinChu branch, HsinChu, Taiwan; Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Medicine, College of Medicine, National Taiwan University, Taipei; Taiwan.
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Chang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Primary Care Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Chau-Chung
authors.initials: CC
authors.lastname: Wu
authors.affiliation: Department of Internal Medicine, Taipei Medical University Hospital, Taipei Taiwan.
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Lin
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Nuclear Medicine and. Cardiology Division of Cardiovascular Medical Center, Far Eastern Memorial Hospital, New Taipei City, Taiwan; Departments of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan.
authors.forename: Yen-Wen
authors.initials: YW
authors.lastname: Wu
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, HsinChu branch, HsinChu, Taiwan.
authors.forename: Ying-Chieh
authors.initials: YC
authors.lastname: Yang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Medicine, College of Medicine, National Taiwan University, Taipei; Taiwan.
authors.forename: Tien-Jyun
authors.initials: TJ
authors.lastname: Chang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Medicine, College of Medicine, National Taiwan University, Taipei; Taiwan.
authors.forename: Yi-Der
authors.initials: YD
authors.lastname: Jiang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Medicine, College of Medicine, National Taiwan University, Taipei; Taiwan; Institute of Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Lee-Ming
authors.initials: LM
authors.lastname: Chuang
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D005260:Female; D006801:Humans; D053798:Magnetocardiography; D008297:Male; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000209:etiology*; D012307:Risk Factors