Echocardiogram. An important test for diagnosing heart failure is the echocardiogram. An echocardiogram helps distinguish systolic heart failure from diastolic heart failure in which the heart is stiff and can't fill properly.
An echocardiogram uses sound waves to produce a video image of your heart. This test can help doctors see the size and shape of your heart and how well your heart is pumping.
The echocardiogram also can help doctors look for valve problems or evidence of previous heart attacks, other heart abnormalities, and some unusual causes of heart failure.
Your ejection fraction is measured during an echocardiogram and can also be measured by nuclear medicine tests, cardiac catheterization and cardiac MRI. This is an important measurement of how well your heart is pumping and is used to help classify heart failure and guide treatment.