Aneurysm: A localized widening (dilatation) of an artery, a vein, or the heart. At the point of an aneurysm, there is typically a bulge. The wall of the blood vessel or organ is weakened and may rupture. From Healthy Heart Resources Diagnosing Hypertrophic CardiomyopathyExercising With HCM: How to Sweat SafelyWhen Chronic Heart Failure Gets Worse Featured Centers What Are the Best PsA Treatments for You?Understanding Biologics 10 Things People With Depression Wish You Knew