Heart attacks

a. almost always result in instant death

b. can be mild, moderate, or severe

c. do not result in necrosis of heart tissue

d. can only be detected using an arteriogram

The correct option is : b. can be mild, moderate, or severe

Explanation:

Myocardial infarction, or heart attack, is a medical condition that occurs when the flow of blood stops or decreases to the human heart, thus causing damage to the heart muscles. Some of the symptoms include chest pain, nausea, sweating, cold sweat, fatigue, etc.

Heart attacks can be mild, moderate or severe and can also cause sudden death.

If the inadequate blood flow to the heart lasts long enough, it can lead to necrosis of the heart tissues.

Myocardial infarction can be diagnosed by electrocardiogram (ECG), echocardiogram, blood tests, X-ray, angiogram, MRI.