Electrocardiographic Differentiation of the ST-Segment Depression of Acute Myocardial Injury Due to the Left Circumflex Artery Occlusion from that of Myocardial Ischemia of Nonocclusive Etiologies

Absence of ST elevation in ECG leads V7, V8, V9 in ischaemia of non-occlusive aetiologies

“…The 12-lead ECG in circumflex coronary artery occlusion may show either ST segment elevation, ST segment depression or no abnormality, each occurring in approximately onethird of the patients [3]. In patients presenting with inferior ST-elevation myocardial infarction, several criteria to distinguish between circumflex artery and right coronary artery occlusion have recently been described in the literature [4,9].…”

“…In patients presenting with inferior ST-elevation myocardial infarction, several criteria to distinguish between circumflex artery and right coronary artery occlusion have recently been described in the literature [4,9]. It has also been reported that in patients presenting with circumflex artery occlusion and isolated ST segment depression, this ECG abnormality occurs most frequently in leads V1 to V4 [3,6]. Our study confirms that in patients presenting with subendocardial myocardial ischaemia, which is induced during treadmill stress test, ST segment depression is seen mainly in leads V4 to V6 and in leads II, III and aVF ( Table 2) as was previously documented by other investigators [3,10,11].…”

“…Occlusion of the left circumflex coronary artery may present with either: (i) ST segment elevation in the inferior leads II, III, aVF and the lateral leads I, aVL, V5 and V6, (ii) ST segment depression in the praecordial leads V1 to V4 or (iii) a normal electrocardiogram (ECG) [1][2][3][4].…”

High-frequency QRS electrocardiogram analysis during exercise stress testing for detecting ischemia

“…The current gold standard for evaluation is coronary angiography, but because it is invasive, expensive and involves certain risks, the 12-lead electrocardiogram (ECG), exercise testing and a targeted patient history are commonly used for initial screening [1,2].…”

A different look at the conventional 12-lead electrocardiogram

“…1). When significant ST elevation occurs at the end of an arc, such as only in lead + III or only in lead + aVL, using a lead pair such as -aVL and -III helps establish STEMI criteria for the diagnosis of inferolateral or superolateral infarctions [8]. The application of a 24-leads ECG is not routinely feasible in emergency department.…”