Which symptom is indicative of a myocardial infarction (MI)?

The symptom indicative of a myocardial infarction (MI) is substernal chest pressure that is relieved only by opioids. This symptom is significant because it suggests more severe and sustained ischemia of the heart muscle, which is characteristic of a myocardial infarction. Unlike other forms of chest pain, which may be exertional or relieved by rest or nitroglycerin, the severe postural nature of this pressure as well as its resistance to common treatments highlights the urgency and seriousness of an MI.

In the context of MI, patients typically report a feeling of pressure, tightness, or heaviness in the chest area, often associated with radiation to the arms, back, neck, or jaw. The fact that the discomfort is relieved primarily by opioids indicates significant pain levels commonly experienced during an MI, further emphasizing the need for immediate medical intervention.

The other symptoms described can indicate different types of angina or non-cardiac related chest discomfort. For instance, chest pain brought on by exertion or stress typically relates to stable angina, while substernal discomfort occurring at rest may be indicative of unstable angina, which is different from full-blown myocardial infarction. Lastly, the symptom that is relieved by nitroglycerin or rest usually