It has been suggested that these changes arise from the same mechanisms that create the hyperacute T-waves that can precede ST elevation MIs.3 Hyperacute T-waves arise from a shortening of the action potential in the ischemic myocardium which alters repolarization leading to increased T-wave amplitude in affected leads. When this process is superimposed on regions of the myocardium that have chronic ischemic changes, the effect is flattening and eventually positive T-wave transformation.

Pseudonormalization in the absence of the correct clinical context may not carry a high sensitivity nor positive predictive value. In a study looking at stress tests from 4,353 participants, 140 patients exhibited pseudonormalization but only 33 patients had a reversible perfusion defect on SPECT imaging.⁴ In a similar investigation of 50 patients noted a relationship between pseudonormalization and ischemia although the study was underpowered to meet clinical significance.⁵ Studies looking at this phenomenon in the emergency department setting for patients presenting with chest pain are lacking. Considering hyperacute T-waves have been accepted as STEMI equivalents, it is possible that pseudonormalization could gain more recognition as an indicator of ACS.⁶

This case shows the importance of close comparison of an active EKG to prior EKGs, especially without knowing the full clinical scenario. Having an understanding of the pseudonormalization of T waves should serve as another tool in our diagnostic toolbox when reviewing EKGs from triage can help expedite emergent department care. This can be used with other aspects of the clinical presentation to more effectively stratify the need for admission and cardiology consultation.

Dr. Young is an emergency physician at Saint Francis Hospital and Medical Center, Hartford, Conn.

References

1. Noble RJ, Rothbaum DA, Knoebel SB, McHenry PL, Anderson GJ. Normalization of abnormal T waves in ischemia. Arch Intern Med. 1976 Apr;136(4):391-5.
2. Chierchia S, Brunelli C, Simonetti I, Lazzari M, Maseri A. Sequence of events in angina at rest: Primary reduction in coronary flow. Circulation. 1980 Apr;61(4):759-68.
3. Simons A, Robins LJ, Hooghoudt TE, Meursing BT, Oude Ophuis AJ. Pseudonormalisation of the T wave: old wine?: A fresh look at a 25-year-old observation. Neth Heart J. 2007;15(7-8):257-9.
4. Loeb HS, Friedman NC. Normalization of abnormal T-waves during stress testing does not identify patients with reversible perfusion defects. Clin Cardiol. 2007 Aug;30(8):403.
5. Fuentes Mendoza JA, Gonzalez Galvan LM, Guizar Sanchez CA, Pimentel-Esparza JA, Fuentes Jaime J, Cervantes-Nieto JA. Pseudo-Normalization of the T-wave during stress and its relationship with myocardial ischemia: Evaluation by myocardial Perfusion single photon emission computed tomography (SPECT). Cureus. 2023 May 2;15(5):e38428.
6. Kontos, M, de Lemos, J. et al. 2022 ACC Expert Consensus Decision Pathway on the Evaluation and Disposition of Acute Chest Pain in the Emergency Department: A Report of the American College of Cardiology Solution Set Oversight Committee. J Am Coll Cardiol. 2022 Nov, 80 (20) 1925–1960.