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Influence of early coronary reperfusion on QT interval dispersion after acute myocardial infarction
Y Endoh1, H Kasanuki, S Ohnishi
1Department of Cardiology, Saisei-kai Kurihashi Hospital, Saitama, Japan.
Insights
Early reperfusion therapy after acute myocardial infarction (MI) may reduce QT dispersion, indicating improved electrical stability. This finding suggests a potential benefit for patients undergoing prompt treatment for MI.
Area of Science:
- Cardiology
- Electrophysiology
Background:
- Acute myocardial infarction (MI) poses significant risks, including life-threatening arrhythmias.
- QT interval dispersion is a marker of cardiac electrical instability.
- Early reperfusion therapy is a cornerstone in managing acute MI.
Purpose of the Study:
- To investigate the impact of early coronary reperfusion on QT interval dispersion in patients with acute myocardial infarction.
- To assess electrophysiological stability following reperfusion in MI patients.
Main Methods:
- Compared QT dispersion and corrected QT (QTc) dispersion in three groups of acute MI patients: early reperfusion, non-early reperfusion, and no vessel recanalization.
- Analyzed electrophysiological parameters at acute and recovery phases post-MI.
Main Results:
- No significant differences in QT or QTc dispersion were observed during the acute phase across all groups.
- Significant differences in QT and QTc dispersion emerged during the recovery phase, with lower values in the early reperfusion group.
- A significant reduction in QTc dispersion from the acute to recovery phase was noted in the early reperfusion group.
- Premature ventricular contractions were less frequent in patients with early or non-early reperfusion compared to those without vessel recanalization.
Conclusions:
- Early coronary reperfusion in acute MI patients is associated with reduced QT dispersion in the recovery phase.
- This reduction in QT dispersion suggests improved electrophysiological stability following prompt reperfusion therapy.
- Early reperfusion may mitigate the risk of arrhythmias by stabilizing cardiac electrical activity.
Abstract:
We studied the influence of early coronary reperfusion on QT interval dispersion in patients with acute myocardial infarction (MI). There were 54 males and 18 females with a mean age of 60 +/- 10 years. Of the 51 patients with recanalization of the infarct related vessel in the recovery phase, 28 (group A) had early coronary reperfusion (5.5 +/- 2.7 hours), 23 other patients (group B) were not confirmed with early coronary reperfusion. Twenty-one patients (group C) did not undergo recanalization of the infarct related vessel in the recovery phase. Corrected QT (QTc) maximum, QTc minimum, and QTc dispersion calculated as the difference between the maximum and minimum QTc intervals, were compared among these three groups at both acute and recovery phase. At the acute phase after MI, there were no significant differences in the QTc maximum, QTc minimum, QT dispersion, and QTc dispersion among these three groups. At the recovery phase after MI, there were also no significant differences in the QTc maximum and QTc minimum. However, there were significant differences in the QT dispersion (0.035 +/- 0.010 in group A, 0.049 +/- 0.015 in group B, and 0.061 +/- 0.031 s in group C, respectively; P = 0.0001), and QTc dispersion (0.038 +/- 0.012 in group A, 0.050 +/- 0.015 in group B, and 0.063 +/- 0.032 s in group C, respectively; P = 0.0003) among the three groups. Comparison of QTc dispersion between acute and recovery phase revealed significant reduction from acute to recovery phase in group A. The number of premature ventricular contraction was lower in group A and B than group C. In summary, early coronary reperfusion may reduce electrophysiological instability by reducing QT dispersion in the recovery phase after acute MI.