Cardiomegaly: Meaning in a Radiology Report

Also written as: enlarged heart, enlarged cardiac silhouette, cardiac enlargement, increased cardiothoracic ratio

Cardiomegaly means the heart looks larger than normal, usually on a chest X-ray. It is a sign that needs explaining, not a diagnosis by itself.

What it means

On a chest X-ray, the heart shows as a white shape in the middle of the chest. Radiologists compare its width with the width of the chest. If the heart takes up more than about half, it is called enlarged. The outline can look larger than the heart really is. This happens on X-rays taken lying down or front to back (AP), with a shallow breath, or when fluid or fat surrounds the heart.

When it matters

An enlarged outline can come from a heart that works harder, as with high blood pressure or a leaky or narrowed valve, from a weakened heart muscle, or from fluid around the heart. It can also be a false impression from how the X-ray was taken. An ultrasound of the heart (echocardiogram) is the usual next test to measure its size and pumping. Comparing with older X-rays also helps.

Questions to ask your doctor

Was the X-ray taken standing or lying down, and could that make my heart look larger?
Do I need an echocardiogram to check the size and pumping of my heart?
Is the enlargement new compared with my earlier chest X-rays?

General information, not medical advice. What a finding means for you depends on your symptoms, your history and the images themselves, so talk your results through with a doctor.