What is characterized by destruction of heart tissue due to obstruction of blood supply, often accompanied by spontaneous pain?

Myocardial infarction, also known as a heart attack, is characterized by the destruction of heart tissue due to a lack of blood supply, usually as a result of blockage in one or more coronary arteries. This interruption in blood flow leads to ischemia, which can cause significant damage to the heart muscle if not quickly resolved. One of the key features of a myocardial infarction is the presence of spontaneous, often severe pain, typically described as a crushing sensation in the chest.

In contrast, conditions such as angina pectoris involve chest pain due to temporary decreases in blood flow, but they do not lead to irreversible heart tissue damage like a myocardial infarction. Heart failure refers to the heart's inability to pump blood effectively, which can be a result of various heart conditions, including myocardial infarction, but does not specifically denote tissue destruction due to obstruction. Myocarditis refers to inflammation of the heart muscle, which can also cause symptoms but through different mechanisms than those seen in myocardial infarction.

Thus, myocardial infarction is distinctly defined by its destructive effects on heart tissue and its association with spontaneous and intense pain, making it the correct answer.