ST-depression in right precordial leads with inferior STEMI and occluded right coronary artery: intertwined anatomy and ischemic areas

Right coronary artery (RCA) occlusion in inferior acute myocardial infarction is usually heralded by ST-elevation both in inferior and in right precordial leads. We report the case of a 68-year-old male, who presented marked ST-elevation in inferior leads, mirrored by ST-depression in anterior-septal and lateral leads. Right precordial lead electrocardiogram unexpectedly showed ST-depression V1R–V5R leads. Coronary angiography showed mid-left anterior descending (LAD) coronary near-complete occlusion with distal wrapping LAD. Left circumflex artery was not occluded, while RCA was occluded mid tract. The patient was treated with coronary angioplasty on RCA and LAD. Absence of ST-elevation in right precordial leads may be presumably explained by the presence of a large ischemic area distal to mid-LAD near-occlusive stenosis and of a long-wrapping LAD. Complex coronary anatomy and intertwined ischemic areas may underlie apparently discording electrocardiograms.急性下壁心肌梗死伴右冠状动脉（Right Coronary Artery, RCA）闭塞时，通常表现为下壁及右胸导联出现ST段抬高。本文报告1例68岁男性患者，其心电图在下壁导联呈现显著ST段抬高，而前间隔及侧壁导联则呈ST段压低的镜像性改变。令人意外的是，该患者的右胸导联V1R~V5R心电图表现为ST段压低。冠状动脉造影结果显示：左前降支（Left Anterior Descending, LAD）中段近乎完全闭塞，且伴远端缠绕走行；左回旋支未发生闭塞，而右冠状动脉中段存在闭塞。患者随后接受了右冠状动脉及左前降支的冠状动脉成形术治疗。右胸导联未出现ST段抬高的现象，推测可由以下因素共同导致：左前降支中段近乎闭塞性狭窄的远端存在大面积缺血区域，且左前降支存在长段缠绕走行的解剖结构。复杂的冠状动脉解剖结构与相互交织的缺血区域，可能是此类看似矛盾的心电图表现的病理基础。