Objectives: The purpose of this study was to investigate the correspondence between the coronary arterial anatomy and supplied myocardium based on the proposed American Heart Association 17-segment model.
Background: Standardized assignment of coronary arteries to specific myocardial segments is currently based on empirical assumptions.
Methods: A cardiac magnetic resonance study was performed in 93 subjects following acute myocardial infarction treated with primary percutaneous coronary intervention. Two observers blindly reviewed all angiograms to examine the location of the culprit lesion and coronary dominance. Two additional observers scored for the presence of cardiac magnetic resonance hyperenhancement (HE) on a 17-segment model. Segments were divided based on anatomical landmarks such as the interventricular grooves and papillary muscles.
Results: In a per-segment analysis, 23% of HE segments were discordant with the empirically assigned coronary distribution. Presence of HE in the basal anteroseptal, mid-anterior, mid-anteroseptal, or apical anterior wall was 100% specific for left anterior descending artery occlusion. The left anterior descending artery infarcts frequently involved the mid-anterolateral, apical lateral, and apical inferior walls. No segment was 100% specific for right coronary artery or left circumflex artery (LCX) occlusion, although HE in the basal anterolateral wall was highly specific (98%) for LCX occlusion. Combination of HE in the anterolateral and inferolateral walls was 100% specific for a LCX occlusion, and when extended to the inferior wall, was also 100% specific for a dominant or codominant LCX occlusion.
Conclusions: Four segments were completely specific for left anterior descending artery occlusion. No segment can be exclusively attributed to the right coronary artery or LCX occlusion. However, analysis of adjacent segments increased the specificity for a given coronary occlusion. These findings bring objective evidence in the appropriate segmentation of coronary arterial perfusion territories and assist accurate assignment of the culprit vessel in various imaging modalities.