RESUMEN
PURPOSE: The 12-lead electrocardiogram has limitation for detection of lateral wall myocardial infarction (MI). Therefore, this study was conducted to compare the location of leads V5 and V6 with the left ventricle (LV) lateral wall using multidetector computed tomography (MDCT) and propose new additional leads for detection of lateral wall MI. METHODS: From 120 study subjects who underwent chest MDCT, we measured the angle (Θ) between the midsagittal plane and long axis of LV on the coronal imaging of MDCT. Using this, another angle (90-Θ) between the long axis of LV and leads V5 and V6 was calculated. After the location of the leads V5 and V6 was identified using axial and coronal images of MDCT, the positional relationship between leads V5 and V6 and the lateral wall was compared based on the thoracic spine. RESULTS: The Θ and 90-Θ was 52.2°±10.3°and 37.8°±10.3°, respectively. Leads V5 and V6 faced the LV lateral wall very obliquely. The score of leads V5 and V6 position based on the thoracic spine was 6.9±1.8 points as the level of lower part of 9th vertebral body. Meanwhile, the lateral wall of LV was 4.7±2.2 points as the lower part of the 8th vertebral body. Thus, leads V5 and V6 were located lower by the height of one thoracic vertebral body than the lateral wall of LV on coronal images (p < 0.001). CONCLUSION: Leads V5 and V6 are inappropriate for detection of the lateral wall MI. To diagnose that more efficiently, we propose the new additional leads, elevated V5 and elevated V6, located two or three intercostal spaces upward from leads V5 and V6.