Related Experiment Videos
QRS amplitude and volume changes during hemodialysis
S Ojanen1, T Kööbi, P Korhonen
1Department of Medicine, Tampere University Hospital, Finland. seppo.ojanen@pp.inet.fi
American Journal of Nephrology
|July 7, 1999
Summary
Hemodialysis increases QRS amplitude, likely due to reduced extracellular water (ECW) and increased tissue electrical resistance. This study monitored ECG changes alongside ECW and blood volume during dialysis in 15 patients.
Area of Science:
- Cardiology
- Nephrology
- Biomedical Engineering
Background:
- QRS amplitude increases during hemodialysis, but mechanisms are unclear.
- Suggested causes include myocardial ischemia and fluid volume changes.
- Noninvasive technologies allow synchronous monitoring of ECG and fluid changes.
Purpose of the Study:
- To investigate the relationship between QRS complex changes and extracellular water (ECW)/blood volume (BV) during hemodialysis.
- To explore potential mechanisms behind ECG amplitude alterations in hemodialysis patients.
Main Methods:
- Analyzed hemodialysis-related changes in 15 patients.
- Measured QRS vector difference (QRS-VD) and ST vector magnitude (ST-VM6) using dynamic vectorcardiography.
- Assessed ECW changes via bioimpedance and BV changes using optical reflection; monitored various blood parameters.
Main Results:
- QRS-VD increased significantly (372%) during dialysis (p < 0.001).
- QRS-VD changes correlated significantly with body weight, ECW, and BV.
- No significant ST segment alterations were observed; laboratory parameters also correlated with QRS-VD changes.
Conclusions:
- Increased QRS complex amplitude during hemodialysis correlates with reduced ECW.
- The primary mechanism is likely increased electrical resistance from interstitial fluid loss.