We herein report the case of a 60-year-old man who presented with chest discomfort. Coronary angiography demonstrated that the short left anterior descending artery (LAD) arose from the left main coronary artery and the long LAD from the right coronary sinus of Valsalva, which was confirmed by 64-slice multidetector computed tomography coronary angiography. Single-photon emission computed tomography revealed a significant, almost irreversible degree of hypoperfusion in the anterior wall of the left ventricle, thus indicating that the short LAD was associated with myocardial ischemia and severe atherosclerotic lesions. Therefore, SPECT showed that the myocardium was largely necrotic, and we did not perform angioplasty for the short LAD.