title: Increased variability of the coupling interval of premature ventricular contractions as a predictor of cardiac mortality in patients with left ventricular dysfunction.
abstract: BACKGROUND
  The characteristics and prognostic value of the variability of premature ventricular contraction (PVC) coupling intervals (CIs) for cardiac mortality are not yet decisive.
  
  
  RESULTS
  In 133 consecutive patients (58±14 years old, 53 women) who had left ventricular dysfunction (LVD: ejection fraction <50%) and frequent PVCs (≥10/h) who underwent 24-h ambulatory electrocardiography (AECG) recording and (123)I-metaiodobenzylguanidine myocardial single-photon emission computed tomography simultaneously, the heart rate turbulence onset, slope, and T-wave alternans were analyzed from the 24-h AECG. The CI of the PVCs (MEANNV), standard deviation of the CI of the PVCs (SDNV) as an index of the variability of the PVC CI, and their ratio to the preceding N-N intervals (SDNV/SDNN) were calculated from constructed Poincaré plots using the annotated 24-h AECG QRS data. The primary endpoint was cardiac mortality. The mean follow-up period was 63 months. Among 133 patients, 114 survived (group 1) and 19 (14%, group 2) died during the follow-up. The MEANNVand SDNVwere higher in group 2 (539±104 vs. 599±114 ms, P=0.021; 64±34 vs. 83±37 ms, P=0.022, respectively). The SDNV, PVC count, and delayed heart/mediastinum ratio remained as significant predictors of cardiac mortality in the binary logistic regression analysis.
  
  
  CONCLUSIONS
  These results suggest that the SDNVcould be another adjunctive parameter for predicting cardiac mortality in LVD.
authors.affiliation: Cardiovascular Division, College of Medicine, Yeungnam University Medical Center.
authors.forename: Chan-Hee
authors.initials: CH
authors.lastname: Lee
authors.forename: Kyu-Hwan
authors.initials: KH
authors.lastname: Park
authors.forename: Jong-Ho
authors.initials: JH
authors.lastname: Nam
authors.forename: Jeon
authors.initials: J
authors.lastname: Lee
authors.forename: Yoon-Jung
authors.initials: YJ
authors.lastname: Choi
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Kong
authors.forename: Hyun-Wook
authors.initials: HW
authors.lastname: Lee
authors.forename: Jang-Won
authors.initials: JW
authors.lastname: Son
authors.forename: Ung
authors.initials: U
authors.lastname: Kim
authors.forename: Jong-Seon
authors.initials: JS
authors.lastname: Park
authors.forename: Young-Jo
authors.initials: YJ
authors.lastname: Kim
authors.forename: Dong-Gu
authors.initials: DG
authors.lastname: Shin
mesh_terms: D000328:Adult; D000368:Aged; D002423:Cause of Death; D016009:Chi-Square Distribution; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013318:Stroke Volume; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology; D016277:Ventricular Function, Left; D018879:Ventricular Premature Complexes / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology