BACKGROUND This study aimed to determine the myocardial damage (infarct size provided by cardiac single-photon emission tomography) in early stages of the infarction using longitudinal strain and rotational parameters of the left ventricle. METHODS The study included 66 patients with anterior myocardial infarction (AMI) and 62 patients with inferior myocardial infarction (IMI) who underwent primary percutaneous intervention as well as a control group consisting of 50 healthy subjects. LV rotational parameters based on parasternal short-axis views in basal and apical planes and global longitudinal strain were measured with apical four-chamber, apical two-chamber, and apical long-axis views. RESULTS There was a significant positive correlation between infarct size and GLPSavg (r=-.55 <.001), GTOR angle (r=-.52, P<.001), apical rotation angle (r=-.40 <.001, and EF (r=-.43, <.001). While cutoff values were GLPSavg: 11.9 (AUC=0.78), GTOR angle: 11.4° (AUC=0.77), apical rotation angle: 7.1° (AUC=0.76) for patients with an infarct size greater than 20%, the cutoff values were GLPSavg: 10.7 (AUC=0.75), GTOR angle: 8.7° (AUC=0.86), apical rotation angle: 4.35° (AUC=0.87) for those with an infarct size greater than 40%. CONCLUSIONS GLPSavg, GTOR angle, and apical rotation angle values may be used to determine the extent of infarction in early post-MI period, thereby allowing precautions to be taken for remodeling in early stages.