Implications of Localized ST Depression in a Vascular Territory and Altered Precordial T-Wave Balance in Ischemic Heart Disease

The incidence of acute coronary syndrome (ACS) is rising globally. Electrocardiography is still one of the best diagnostic modalities for it. Although some of the ECG changes of ACS are well known among medical practitioners, there are a handful of ECG changes that do not get the recognition they deserve. Among these are localized ST-segment depressions in a vascular territory and altered precordial T-wave balance. The urgency of management varies among the various subtypes of ACS, especially in low resource settings. ST-segment depression localized to a vascular territory is a sign of ST-elevation myocardial infarction (MI) in the reciprocal lead which may not always be evident and hence, requires emergent reperfusion therapy. On the other hand, altered precordial T-wave balance (T1 > T6, T-wave in V1 > 1.5 mm and upright T-wave in V1) may be predictive of significant coronary artery disease (CAD).