Angina and myocardial infarction are caused by reduced oxygen supply to heart muscles due to coronary artery spasm or obstruction. Angina presents as chest pain and comes in different types based on triggers and severity. It is treated with nitrates, beta blockers, calcium channel blockers, and ranolazine to prevent symptoms and disease progression. Myocardial infarction, also called a heart attack, occurs when blood flow decreases or stops to the heart, damaging the heart muscle. It is diagnosed through cardiac biomarkers and ECG and managed initially with analgesics, anticoagulants, and antiplatelet drugs, followed by lifestyle modifications and secondary prevention medications long-term.