Beyond A and B: exploring a novel dynamic electrocardiogram change in Wellens syndrome

Wellens syndrome is a high-risk electrocardiographic pattern associated with significant left anterior descending (LAD) coronary artery disease. Although Pattern A (biphasic T waves) and Pattern B (deep symmetric T-wave inversion) are recognized, their temporal relationship remains incompletely defined. We aimed to describe the clinical, electrocardiographic, echocardiographic, and angiographic characteristics of patients with spontaneous in-hospital evolution from Pattern A to Pattern B.

This retrospective single-centre study included 51 consecutive patients with Wellens syndrome and angiographic confirmation of significant LAD disease (≥70% stenosis). Serial electrocardiogram (ECGs) obtained during the first 24 h were reviewed by two cardiologists blinded to angiographic findings. Eighteen patients (35.3%) had documented evolution from Pattern A to Pattern B before angiography. Fourteen cases occurred within 6 h of admission and four between 6 and 24 h; all were documented during pain-free intervals. The median left ventricular ejection fraction was 53% (Interquartile Range [IQR], 46-60), and high-sensitivity cardiac troponin was elevated in 12 patients (66.7%). Left anterior descending disease was confirmed in all patients, with isolated LAD involvement in 10 and multivessel disease in eight. Revascularization was performed in 13 patients [10 by percutaneous coronary intervention (PCI) and three by coronary artery bypass grafting]. All PCI procedures achieved Thrombolysis in Myocardial Infarction (TIMI) 3 flow. No in-hospital deaths or major adverse cardiovascular events occurred.

In this cohort of patients with confirmed Wellens syndrome, Pattern A-to-B evolution occurred in approximately one-third of patients before coronary angiography, suggesting that dynamic ECG evolution occurs during the acute phase. Further studies are warranted to determine its diagnostic, prognostic, and therapeutic implications.