Inferior Hypokinesis in Anterior MI
Source: Yoshino H, et al. Am J Cardiol 1998;81:828-833.
Usually, an acute anteroseptal myocardial infarction (MI) due to single vessel left anterior descending (LAD) occlusion results in compensatory hyperkinesis of the inferior wall. Occasionally, inferior hypokinesis is observed and is often ascribed to the LAD wrapping around the apex. Yoshino and colleagues evaluated this phenomenon in 85 patients after acute anteroseptal MI due to angiographically proven isolated LAD disease. Wall motion was assessed by biplane left ventricular cineangiography and analyzed by a computer-based system. Inferior wall motion was predicted by three independent factors: hypertension (OR = 0.53) and infarct related lesion prior to the first diagonal (OR = 0.56) were associated with hypokinesis, and infarct artery patency during the acute phase (OR = 1.56) was associated with hyperkinesis. A LAD lesion proximal to the first diagonal branch was associated with worse LV function and a higher peak creatine kinase level, suggesting a larger infarct. Yoshino et al conclude that, in some patients with acute anteroseptal MI due to isolated LAD disease, the inferior wall develops hypokinesis during the chronic phase and LV function declines. The principle cause of this phenomenon is an infarct artery lesion proximal to the first diagonal branch.
Contrary to the concept that a long LAD that wraps around the apex may cause inferior hypokinesis in an acute anteroseptal MI, there was no difference in LAD length or any other characteristic of the LAD in this study between the patients with and without inferior hypokinesis. Also, a large MI per se was not the only explanation, since whether the infarct related lesion was before or after the first septal perforator did not seem to make a difference. One feature did make sense and that was that the early achievement of infarct artery patency was associated with normal function of the inferior wall in anteroseptal MI. -mhc
You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content