What are the tests for blood around the heart?

Echocardiogram: This is usually diagnosed with echocardiography, an ultrasound of the heart. A chest x-ray can show an enlarged heart shadow, but this can be caused by other things. The echocardiogram can only indicate fluid and doesn't differentiate between blood and other fluid. The definitive diagnosis is made when the fluid is removed by inserting a needle or tube into the space around the heart.

Echocardiogram. : An echocardiogram is a type of ultrasound focused on the heart. It is a non-invasive test that can diagnose fluid (including blood) around the heart.