Which of the following conditions would most likely cause ST segment elevation?

ST segment elevation is often associated with conditions that cause myocardial injury or inflammation. Acute pericarditis is characterized by inflammation of the pericardium, which can lead to changes in the EKG, including ST segment elevation in various leads.

In the context of acute pericarditis, the ST elevation typically appears concave and is usually seen in multiple leads rather than being localized like the elevation seen in ST elevation myocardial infarction (STEMI). This finding helps clinicians differentiate it from other causes of ST segment elevation. The presence of sharp, pleuritic chest pain and a pericardial rub can further support the diagnosis of acute pericarditis when considering the clinical context along with the EKG findings.

Other conditions listed, such as stable angina, heart block, and cardiac arrest, usually do not present with ST segment elevation as a primary feature. Stable angina typically causes transient ST segment depression during exertion due to ischemia but does not generally lead to persistent ST elevation. Heart block may lead to other EKG abnormalities, but does not primarily involve ST segment elevation. Cardiac arrest may show various EKG changes depending on the underlying cause but does not specifically correlate with ST segment elevation.