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Relation between localization of coronary artery disease and local abnormalities in ventricular activation during
H Igarashi1, M Yamaki, I Kubota
1First Department of Internal Medicine, Yamagata University School of Medicine Japan.
Insights
Body surface isochrone maps of ventricular activation can pinpoint myocardial ischemia locations in coronary artery disease patients. Abnormalities on these maps correlate with specific coronary artery blockages, aiding in diagnosis.
Area of Science:
- Cardiology
- Medical Imaging
- Diagnostic Electrocardiography
Background:
- Myocardial ischemia detection is crucial for managing coronary artery disease (CAD).
- Non-invasive methods are needed to accurately localize ischemic regions.
- Previous studies explored electrocardiographic mapping for ischemia detection.
Purpose of the Study:
- To determine if body surface isochrone maps of ventricular activation reflect the location of myocardial ischemia in CAD patients.
- To assess the correlation between abnormal ventricular activation patterns and stenotic coronary arteries.
Main Methods:
- Eighty-seven unipolar electrocardiograms were recorded from 48 CAD patients before and after exercise.
- Index of Ventricular Activation (IVA) was measured for each lead.
- IVA isochrone maps were constructed to identify abnormal activation areas (+2SD area).
Main Results:
- Left anterior descending artery stenosis correlated with abnormalities on the left anterior chest.
- Right coronary artery stenosis correlated with abnormalities on the right lower thoracic surface.
- Left circumflex artery disease showed less clear localization; ST depression was difficult to interpret.
Conclusions:
- Body surface isochrone maps of IVA can localize myocardial ischemia related to left anterior descending and right coronary artery stenosis.
- This mapping technique shows promise for non-invasively identifying the site of ischemia in CAD.
Abstract:
To examine whether or not the location of local abnormalities on body surface isochrone maps reflects the site of myocardial ischemia, 48 coronary artery disease patients without myocardial infarction were studied. Eighty-seven unipolar electrocardiograms distributed over the anterior chest and the back were recorded simultaneously before and after the submaximal treadmill exercise. For each lead, the duration from the QRS onset to the time of the most rapid decrease in QRS voltage was measured (index of ventricular activation [IVA]). Based o the data provided by these 87 leads, IVA isochrone maps (IVA map) in preexercise and in postexercise, as well as IVA maps showing the difference between preexercise and postexercise, were constructed. The IVA was defined as abnormal when it exceeded (mean + 2 SD) the normal range. We called the area with the abnormal IVA, the "+2SD area." In patients having a stenosis in the left anterior descending artery, the +2SD area in each map was located mainly on the left anterior chest, whereas in patients having a stenosis in the right coronary artery, the +2SD area in each map was located mainly on the right lower thoracic surface. Moreover, the +2SD area of patients with both left anterior descending and right coronary artery disease appeared on both the left anterior chest and the right lower thoracic surface. In patients with left circumflex artery disease, however, the location of the +2SD area did not suggest a stenotic site because of its small population. On the other hand, it was difficult to determine the ischemic site from the body surface distribution of ST segment depression.(ABSTRACT TRUNCATED AT 250 WORDS)