title: Isolated ultrafiltration affects dynamic vectorcardiographic ischemia monitoring parameters.
abstract: OBJECTIVE
  The present study was undertaken to assess the role of isolated ultrafiltration (UF phase) and hemodialysis with minimal ultrafiltration (HD phase) in changes in parameters reflecting myocardial ischemia: QRS vector difference (QRS-VD), ST change vector magnitude (STC-VM) and ST vector magnitude (ST-VM6) registered by MIDA (myocardial infarction dynamic analysis).
  
  
  METHODS
  Twelve patients on maintenance hemodialysis were first ultrafiltrated for 2.5 h without dialysis (UF) followed by a 2.5-hour session of hemodialysis with minimal ultrafiltration (HD). Computerized vectorcardiography (VCG) was used for on-line dynamic analysis of ST segment and QRS complex changes. Blood volume (BV) changes were monitored non-invasively and continuously with the CRIT-LINE instrument. Whole-body bioelectric impedance analysis (BIA) was used for extracellular water (ECW) estimation.
  
  
  RESULTS
  During the UF phase QRS-VD and STC-VM showed a statistically significant increasing linear trend (time effect for both QRS-VD and STC-VM p < 0.0001, while no changes were noted in ST-VM6; time effect p = 0.986). During the HD phase none of these parameters changed (time effect for QRS-VD p = 0.855, for STC-VM p = 0.275 and for ST-VM6 p = 0.976). During the UF, phase changes in QRS-VD were in close relation to those in ECW.
  
  
  CONCLUSIONS
  Isolated ultrafiltration leads to an increase in the VCG ischemia monitoring parameters QRS-VD and STC-VM. The increase of QRS-VD is related to changes in ECW. Hemodialysis with minimal ultrafiltration has no effect on VCG ischemia monitoring parameters.
authors.affiliation: Department of Medicine, Tampere University Hospital, Finland. seppo.ojanen@fimnet.fi
authors.forename: S
authors.initials: S
authors.lastname: Ojanen
authors.forename: A M
authors.initials: AM
authors.lastname: Koivisto
authors.forename: T
authors.initials: T
authors.lastname: Kööbi
authors.forename: P
authors.initials: P
authors.lastname: Korhonen
authors.forename: J
authors.initials: J
authors.lastname: Mustonen
authors.forename: P
authors.initials: P
authors.lastname: Laippala
authors.forename: A
authors.initials: A
authors.lastname: Pasternack
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D006435:Renal Dialysis / Q000009:adverse effects*; D014462:Ultrafiltration; D014672:Vectorcardiography