title: Electrocardiography as the First Step for the Further Examination of Cardiac Involvement in Myasthenia Gravis.
abstract: BACKGROUND
  Cardiac involvement of myasthenia gravis (MG) accompanies a poor prognosis. In the present study, we aimed to investigate the relationship between ECG abnormality and cardiac involvement.
  
  
  METHODS
  Of 178 patients diagnosed with MG between 2001 and 2013 at our hospital, we retrospectively analyzed consecutive 58 patients who underwent both ECG and echocardiography and without underlying cardiovascular disease. ECG abnormalities were defined by computer-assigned Minnesota-codes. Cardiac damage was defined as either (1) ejection fraction (EF) <55% on echocardiography or (2) elevated E/e', the ratio of mitral velocity to early diastolic velocity of the mitral annulus >8 on echocardiography.
  
  
  RESULTS
  Thirty-three patients (56.8%) had ECG abnormality. An elevated E/e' was observed in patients with ECG abnormality compared to those without ECG abnormality (11.2 ± 3.2, 8.7 ± 2.2, resp., p = 0.03). Among patients with ECG abnormality, 14 of 15 patients showed cardiac damage. Among patients without ECG abnormality, 6 of 33 patients showed cardiac damage (p = 0.003). Reduced EF was observed in five patients (8.6%) with ECG abnormality and none in patients without ECG abnormality.
  
  
  CONCLUSIONS
  ECG may aid as the first step for the further examination of cardiac damage in patients with MG.
authors.affiliation: Cardiovascular Center, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan; Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Kato
authors.affiliation: Cardiovascular Center, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan.
authors.forename: Sayako
authors.initials: S
authors.lastname: Hirose
authors.affiliation: Cardiovascular Center, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Kumagai
authors.affiliation: Department of Neurology, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Ozaki
authors.affiliation: Department of Neurology, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan.
authors.forename: Sadayuki
authors.initials: S
authors.lastname: Matsumoto
authors.affiliation: Cardiovascular Center, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan.
authors.forename: Moriaki
authors.initials: M
authors.lastname: Inoko
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000503:physiopathology; D009157:Myasthenia Gravis / Q000150:complications / Q000503:physiopathology*; D011379:Prognosis; D013318:Stroke Volume