What are the implications of mild nonspecific inferolateral ST (electrocardiogram segment) changes?

From the Guidelines

Mild nonspecific inferolateral ST changes on an electrocardiogram (ECG) should be interpreted with caution and in the context of the patient's clinical presentation, as they may indicate underlying cardiac conditions or be a normal variant, and further evaluation with serial ECGs, cardiac enzymes, echocardiogram, or stress testing may be necessary, as recommended by the 2011 ACCF/AHA guidelines 1. These findings represent subtle abnormalities in the electrical activity of the heart's inferolateral region (bottom and side walls of the left ventricle) during repolarization. While these changes are often benign, they should not be dismissed without consideration of the clinical context. Some key points to consider include:

• The prognostic information contained within the ECG pattern remains an independent predictor of death even after adjustment for clinical findings and cardiac biomarker measurements 1.
• Nonspecific ST-segment and T-wave changes are less diagnostically helpful than other ECG findings, but still require clinical correlation and possible further evaluation 1.
• The term "nonspecific" indicates that the pattern does not clearly point to a single diagnosis, which is why clinical correlation is essential for proper interpretation and management.
• The management of patients with suspected acute coronary syndromes without persistent ST-segment elevation, such as those with mild nonspecific inferolateral ST changes, should be based on risk stratification and may include antiplatelet, antithrombin, and antianginal therapy, as well as an invasive strategy in patients with positive biomarkers or unstable clinical features 1. It is also important to note that a completely normal ECG in a patient with chest pain does not exclude the possibility of acute coronary syndrome (ACS), as 1% to 6% of such patients may eventually be proven to have had a myocardial infarction (MI) 1. Therefore, clinical correlation and further evaluation are essential for patients with mild nonspecific inferolateral ST changes on an ECG, as recommended by the 2011 ACCF/AHA guidelines 1.

From the Research

Implications of Mild Nonspecific Inferolateral ST Changes

• The implications of mild nonspecific inferolateral ST changes can be varied and may not always be directly related to cardiac issues 2, 3, 4, 5, 6.
• In some cases, these changes can be associated with coronary vasospasm, which can result in significant ST changes and hemodynamic compromise 2.
• Mild ST-segment elevation in the inferolateral leads can also be a sign of a concealed type of Brugada syndrome 3.
• Additionally, inferolateral ST elevation can be an atypical presentation of acute cholecystitis, which can be initiated by gallbladder distension due to biliary duct occlusion caused by gallstones 4.
• In other cases, inferolateral ST elevation can be a sign of left anterior descending artery occlusion, particularly in patients with a history of anteroseptal myocardial infarction or other coronary abnormalities 5.
• Nonspecific electrocardiographic abnormalities, including mild nonspecific inferolateral ST changes, are associated with increased length of stay and adverse cardiac outcomes in patients with prehospital chest pain 6.
• These findings suggest that mild nonspecific inferolateral ST changes should be carefully evaluated and monitored, as they can be a sign of underlying cardiac or non-cardiac conditions that require prompt attention and treatment 2, 3, 4, 5, 6.