So Wellens syndrome is a STEMI equivalent right? That is part of it, but not the whole picture. When we say STEMI or STEMI-equivalent, the image of a fully occluded coronary artery that requires immediate PCI comes to mind. Wellens syndrome is not really a “STEMI” but more of a post-STEMI or a pre-STEMI (along with being a non-STEMI). I’ll explain why.
First we will review Wellens syndrome and then we’ll go into what it represents. Symptoms usually include resolved angina, either spontaneously or after treatment (nitro, aspirin). The troponin will be negative or minimally elevated & the EKG will not show signs of irreversible ischemia such as deep Q waves or poor R wave progressions. Lastly, you’ll see T-Wave Inversions in the anterior leads. There are two types of Wellens waves, pictured below and they occur when chest pain is resolved. Resolved chest pain means the artery has spontaneously reopened and the myocardium is being perfused. Thus Wellens waves are reperfusion waves, rather than waves that represent an acute coronary occlusion.
However, if these patients do not receive PCI at some point, they are at high risk for large anterior MI due to near occlusion of the LAD.
The phenomenon of pseudonormalization also occurs in Wellens syndrome, further making it easy to accidentally discharge these patients. In pseudonormalization, recurrence of chest pain results in normalization of T waves and elevation of ST segments. When the T waves are inverted, the artery is open (albeit barely) because the T waves represent reperfusion. When the patient develops chest pain (since the artery has fully closed), the T waves flip on their way to becoming hyperacute T waves. Catching an EKG at this unfortunate time could deceive you into thinking the patient has a “normal” EKG
This nearly occluded lesion is classically associated with LAD and thus usually seen in the anterior leads. However, a 99% coronary lesion and thus occlusion/reperfusion phenomenon known as Wellens can occur in any coronary artery. For example, you'll see Wellens in the inferior leads for RCA lesions that spontaneously reopen.
While resolved symptoms and EKG signs of reperfusion don’t require immediate cath lab activation, post-ischemic TWI require aggressive treatment while waiting for PCI. These are the highest risk NSTEMIs! Include these findings in your signouts. Be on the lookout for return of chest pain, which points towards acute reocclusion & do not be fooled by pseudonormalization. Also patients who have TWI and active CP are patients with typical ACS/NSTEMI, not necessarily Wellens/99% coronary artery occlusion.
Wellens is a normal reassuring finding post cath lab since it means the interventionalist has successfully reperfused the coronary. It is scary in the ED because it was spontaneous reopening, which could mean an entire wall of the LV is only being supplied by an artery that is 1% open.
