title: Changes in follow-up ECG and signal-averaged ECG in patients with arrhythmogenic right ventricular cardiomyopathy.
abstract: BACKGROUND
  Electrocardiogram (ECG) and signal-averaged ECG (SAECG) are important as diagnostic tools in arrhythmogenic right ventricular cardiomyopathy (ARVC). The aim of this study was to investigate changes in follow-up ECGs and SAECGs in patients with ARVC.
  
  
  METHODS
  We collected 185 follow-up ECGs from 38 patients and 35 follow-up SAECGs from 18 patients during a mean follow-up period of 64 ± 36 months.
  
  
  RESULTS
  On baseline ECG and SAECG, epsilon waves, T-wave inversion (TWI), and terminal activation delay (TAD) of QRS ≥ 55 ms in right precordial leads, and late potentials (LPs) were observed in six (16%), 11 (29%), 13 (34%), and 23 (68%) patients, respectively. During the follow-up period, 15 (39%) patients had 18 changes in ECG and/or SAECG features included in modified Task Force Criteria (TFC) of ARVC. Two patients developed new epsilon waves, and another two patients had dynamic epsilon waves. Newly developed TAD of QRS ≥ 55 ms was observed in two patients and disappeared in one patient. Eight patients, seven with and one without TWI in V1 -V3 or beyond, showed dynamic changes. LP developed in three patients. One patient with dynamic change of TWI and another patient with dynamic change of epsilon wave and TAD of QRS ≥ 55 ms could not satisfy the modified TFC during follow-up.
  
  
  CONCLUSIONS
  Follow-up ECGs and SAECGs showed changes in 39% of patients with ARVC. Larger studies with a longer follow-up period are needed to investigate the clinical implications of changes in follow-up ECG and SAECG.
authors.affiliation: Department of Internal Medicine, Kyungpook National University Hospital, Daegu, South Korea.
authors.forename: Myung Hwan
authors.initials: MH
authors.lastname: Bae
authors.forename: Jae Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Se Yong
authors.initials: SY
authors.lastname: Jang
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Park
authors.forename: Jang Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Dong Heon
authors.initials: DH
authors.lastname: Yang
authors.forename: Hun Sik
authors.initials: HS
authors.lastname: Park
authors.forename: Yongkeun
authors.initials: Y
authors.lastname: Cho
authors.forename: Shung Chull
authors.initials: SC
authors.lastname: Chae
mesh_terms: D000465:Algorithms; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: arrhythmogenic right ventricular cardiomyopathy/dysplasia; electrocardiography