Blood normally flows freely through the coronary arteries, delivering oxygen to the heart with every beat. Over years, cholesterol slowly builds along the vessel wall, forming plaque. As this plaque grows, the artery narrows and the wall becomes fragile. Without warning, the plaque can rupture, spilling its contents into the bloodstream. Platelets rush in immediately, forming a blood clot that can quickly block the artery and stop blood from reaching the heart muscle beyond the blockage. Deprive