Different impacts of acute myocardial infarction on left ventricular apical and basal rotation

The impacts of acute myocardial infarction (AMI) with different regional wall motion abnormalities on left ventricular (LV) rotation have not been well investigated. We assessed the impacts of AMI on LV rotational mechanics and to compare the alterations in basal and apical rotation between patients with anterior and inferior AMI.

Thirty-five patients with anterior AMI and 31 patients with inferior AMI who had a single culprit lesion were analysed. Thirty age-matched subjects were included for controls. The apical and basal rotations were obtained and LV twist and torsion were measured by two-dimensional speckle tracking imaging. Compared with normal, LV twist was reduced in all AMI patients. The basal rotation was larger in anterior AMI than in inferior AMI and normal (-9.0 ± 2.6 vs. -3.4 ± 2.1° and -6.0 ± 1.9°, P < 0.001), although the apical rotation was lower in anterior AMI. As a result, LV twist and torsion were not different between anterior AMI and inferior AMI (17.0 ± 4.6 vs. 16.7 ± 3.3° and 2.08 ± 0.59 vs. 2.07 ± 0.44°/cm, P = NS, respectively), although LV ejection fraction was lower in anterior AMI. By multivariate analysis, LV torsion [odds ratio (OR) =0.13, 95% confidential interval (CI) = 0.02-0.75, P = 0.02] and basal rotation (OR = 0.67, 95% CI = 0.45-1.00, P = 0.05) were independently related to LV recovery in patients with anterior AMI and in patients with inferior AMI, respectively.

Although LV twist and torsion were decreased either by reduced apical and basal rotation in AMI patients; the basal rotation was rather increased in anterior AMI. LV functional recovery can be predicted by LV torsion in anterior AMI and by basal rotation in inferior AMI. The basal rotation has often been ignored; however, our findings suggest that the basal rotation has an important role in LV function.