BACKGROUND: The Wellens' electrocardiogram (ECG) pattern of dynamic T-wave 
inversion in the anterior leads is observed in clinical conditions characterized 
by reversible left ventricular (LV) dysfunction (stunned myocardium), either 
ischemic or nonischemic. The pathophysiologic basis of this ECG pattern remains 
to be elucidated.
OBJECTIVE: The purpose of this study was to report the contrast-enhanced cardiac 
magnetic resonance (CE-CMR) findings in 4 cases of Wellens' ECG pattern 
associated with transient LV dysfunction from a variety of clinical conditions 
such as myocardial bridge, coronary artery dissection, cholecystitis, and 
takotsubo syndrome.
METHODS: All patients underwent CE-CMR at the time of acute clinical 
manifestations and after 6 to 8 weeks of follow-up to assess the presence and 
dynamics of LV myocardial changes.
RESULTS: In all patients, the Wellens' ECG abnormalities were associated with 
increased signal intensity of the LV myocardium on T2-weighted sequences 
suggesting myocardial edema, in the absence of late enhancement on postcontrast 
sequences. Repolarization abnormalities and myocardial edema had a parallel time 
course with persistence beyond recovery of mechanical abnormalities. T-wave 
inversion was associated with transient prolongation of the QTc interval in all 
cases.
CONCLUSION: The study results suggest that myocardial edema rather than systolic 
dysfunction underlies the Wellens' ECG pattern, regardless of the causative 
mechanism.