Novel precordial mid-T-wave inversion: a pulsation artifact mimicking myocardial ischemia and proposed mechanisms

Electrocardiographic (ECG) artifacts mimicking acute coronary syndrome (ACS) pose a risk of misdiagnosis and unnecessary procedures. While arterial pulsation artifacts are known to cause limb-lead ST-T changes adhering to the “single-limb lead exemption principle,” their potential to induce specific repolarization abnormalities in precordial leads remains unreported. A 66-year-old woman presented with chest tightness. The initial ECG showed ST-segment elevation in leads III and aVF, depression in I and aVL, and a previously undescribed pattern of isolated mid-portion T-wave inversions in precordial leads V2–V6, with preserved initial T-wave morphology. Suspected ACS was reconsidered after a senior physician noted atypical features. The diagnosis of radial artery pulsation artifact was confirmed after repositioning the limb electrodes away from the radial pulse, which normalized all ECG abnormalities Coronary computed tomography angiography revealed only mild atherosclerosis, ruling out acute ischemia. To our knowledge, this case is the first to describe a previously unreported variant manifestation of arterial pulsation artifact featuring isolated mid-portion T-wave inversions in precordial leads. We propose a potential mechanism via propagation of limb-derived interference currents through the Wilson Central Terminal, combined with an electromechanical hypothesis. This pattern, especially when combined with the limb lead exemption principle (spared lead II localizing the source to the left arm), suggests a potential electrocardiographic sign for differentiating artifact from true pathology. We also propose a practical bedside approach integrating lead-specific analysis and electrode repositioning to prevent misdiagnosis.