Had a abnormal chest x-ray it says vertical density in the retrocardic region what does it mean?

Nondiagnostic: This x-Ray finding in and of itself is nondiagnostic and further evaluation will probably involve a chest ct scan. Your physician will review your chest x-Ray with the radiologist and decide what further imaging studies are advisable as the density behind the heart shadow could be an abnormal blood vessel or a growth. A cardiothoracic surgeon may also be consulted.

Vertical density: many possibilities. You need to follow up with your doctor to find anwers to your questions. You may need to see a chest specialist e.g. a pulmonologist.