Current medical interventions that are established based on lots of clinical evidence have improved the short-term mortality in acute coronary syndrome (ACS). In particular, primary percutaneous coronary intervention (PCI) has contributed to decrease sudden cardiac death and preserve cardiac function. [1,2] Electrocardiography (ECG) is a traditional modality but plays an important role for prompt diagnosis and revascularization even in the modern imaging era.

Several unique ECG patterns, which differ from typical ischemic changes, called de Winter pattern and Wellens' syndrome have been reported among patients with ACSs in daily clinical practice. These patterns are characterized by specific T-wave changes and ST-segment deviation commonly caused by a severe left anterior coronary artery (LAD) lesion. The de Winter pattern is characterized by upsloping ST-segment depression with prominent T waves in the precordial leads, and the Wellens pattern is characterized by minimally-elevated ST-segments with deeply-inverted or biphasic T waves. [3,4] Typically, Wellens' syndrome is recorded as a post-ischemic phenomenon, while the de Winter pattern is recorded during ischemia.

However, the epidemiological characteristics and prognosis of these patterns have not been established because of their rare occurrence, especially in the current, prompt revascularization strategy era.

To address the clinical features in patients with unique ECG patterns, namely the de Winter pattern and Wellens' syndrome, the present study compared the baseline characteristics and prognosis to other ACSs with common ECG patterns.