The following is a summary of “Hyperacute T Wave in the Early Diagnosis of Acute Myocardial Infarction,” published in the August 2023 issue of Emergency Medicine by Koechlin et al.

The diagnostic efficacy of T-wave amplitudes in identifying myocardial infarction remains largely uncertain. The researcher’s objective was to address this deficit in medical knowledge. T-wave amplitudes were automatically assessed in the 12-lead electrocardiograms (ECGs) of patients who presented with acute chest discomfort to the emergency department as part of a prospective diagnostic multicenter study. Two independent cardiologists centrally adjudicated the ultimate diagnosis. The study did not include patients presenting with left ventricular hypertrophy, entire left bundle branch block, or paced ventricular depolarization. 

The results for lead-specific 95th-percentile thresholds were documented in terms of likelihood ratios (LR), specificity, and sensitivity. Myocardial infarction was determined to be the ultimate diagnosis in 445 (18%) out of 2,457 patients. In most cases, patients without myocardial infarction exhibited higher T-wave amplitudes than those with myocardial infarction. Additionally, when the T-wave amplitude surpassed the 95th percentile, there was a close to 1 positive and negative likelihood ratio, with CIs intersecting 1.

The exceptions were leads III, aVR, and V1, which exhibited positive likelihood ratios (LRs) of 3.8 (95% CI, 2.7 to 5.3), 4.3 (95% CI, 3.1 to 6.0), and 2.0 (95% CI, 1.4 to 2.9), respectively. These leads typically exhibit inverted T waves; therefore, an upright T-wave amplitude exceeding the 95th percentile indicates the presence of vertical hyperacute T waves rather than an increase in amplitude. Hyperacute T waves, characterized by an elevation in T-wave amplitude surpassing the 95th percentile, did not yield clinically significant findings to diagnose myocardial infarction within this study population.

Source: sciencedirect.com/science/article/abs/pii/S0196064422013270