is when a part of coronary artery or vessels transporting nutrients to the heart is blocked either by fats or any other substance that first results in myocardia ischemia
or loss of nutrient transport to the heart ...which in turn result in myocardia infarction
or heart attack.
why coronary artery..well its one of the branches of aorta that helps in nutrient supply to the heart ..nutrients like oxygen...oxygenated blood e.t.c
...hardening and thickening of vessels with fats can result in heart attack