Final answer:
The patient's symptoms indicate unstable angina or a potential myocardial infarction, both of which require urgent medical attention and are diagnosed through ECG changes and specific blood markers.
Step-by-step explanation:
Based on the information provided, the type of diagnosis that might be indicated by symptoms such as pain at rest lasting more than 15 minutes, suggests unstable angina or a possible myocardial infarction (MI). Unstable angina requires immediate medical attention as it could be a precursor to an MI, which is confirmed by an electrocardiogram (ECG) showing alterations in ST and Q components, and elevated blood markers like creatine kinase MB and cardiac troponin. It is critical to distinguish these conditions from others like congestive heart failure or mitral valve stenosis, which have different treatment approaches.