Myocardial electrical impedance correlates with ischemic ECG ST-segment changes in humans.
R Dzwonczyk1, C L del Rio, B Sun
1Dept. of Anesthesiology, Ohio State Univ., Columbus, OH 43210, USA.
Summary
Electrocardiogram ST-segment changes and myocardial electrical impedance (MEI) both detect ischemia during surgery. This study found MEI changes are equivalent to ST-segment changes for diagnosing myocardial ischemia.
Area of Science:
- Cardiology
- Medical Devices
- Surgical Monitoring
Background:
- Electrocardiogram (ECG) ST-segment changes are standard for diagnosing myocardial ischemia.
- Myocardial electrical impedance (MEI) is an electrical parameter also responsive to ischemic events.
- Off-pump coronary artery bypass graft (OPCABG) surgery provides a context to evaluate ischemia monitoring techniques.
Purpose of the Study:
- To compare the efficacy of ST-segment changes versus MEI changes in detecting myocardial ischemia during OPCABG surgery.
- To determine if MEI is a viable alternative or equivalent measure to ST-segment changes for real-time ischemia monitoring.
Main Methods:
- Recorded MEI and ST-segment changes in eight patients undergoing OPCABG surgery.
- Occluded the left anterior descending artery (LADa) to induce controlled ischemia.
- Compared MEI changes with concurrent ST-segment changes during LADa occlusion.
Main Results:
- A direct and significant correlation was observed between MEI changes and ST-segment changes.
- Both parameters responded to the ischemic period induced by LADa occlusion.
- MEI changes demonstrated a comparable response to ischemia as ST-segment changes.
Conclusions:
- Myocardial electrical impedance (MEI) is equivalent to ST-segment changes in measuring myocardial ischemia during OPCABG.
- MEI offers a potentially valuable alternative for real-time ischemia monitoring in cardiac surgery.
- Further research can explore the broader clinical application of MEI in cardiology.
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