Have you ever heard of someone who suffered a heart attack, and yet he or she had a total cholesterol level that was in the “normal” range? Unfortunately, it’s not that uncommon. And now we think we know why.

We’re learning that it’s not only the amount of LDL (bad) cholesterol in your blood that’s important. The size of the particles that comprise that cholesterol is also a major factor in heart health. In fact, there are two sizes of cholesterol, which scientists call Pattern A and Pattern B.

Pattern A cholesterol particles are large and “fluffy.” They bounce harmlessly off the walls of coronary arteries as they flow in the bloodstream. Pattern B particles, on the other hand, are tiny and can burrow into the walls of your coronary arteries. When these particles burrow into the vessel walls, the damage they cause makes the blood vessel vulnerable to buildup of fatty deposits. This leads to atherosclerosis (hardening of the arteries).

People who are told their LDL cholesterol is in the safe range could be given a false sense of security if their LDL cholesterol is made of Pattern B particles.

To find out how many of these Pattern B particles you have in your blood, ask your doctor for an advanced lipid test. The results will show your LDL, HDL, and triglyceride levels, plus the amount of Pattern B particles you have.

This information can literally make the difference between life or death. In advanced cholesterol readings, Pattern B cholesterol will show up either designated as apoB or as an elevated level of LDL-P. These measures are interchangeable (some testing companies use one, and some use the other).

In the case of apoB, the ratio of that reading should be less than 0.6. In the case of an LDL-P measurement, the particle number should be less than 1,000.