CPT code 78428 identifies a diagnostic procedure performed to detect a left-to-right shunt in the heart—an abnormal passage of blood from the left to the right cardiac chambers. This code matters nationally because detection of intracardiac shunts informs clinical management for congenital and acquired heart defects and can affect hospital and imaging resource utilization. Payers commonly involved in coverage and claims for this type of cardiac diagnostic service include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will find a concise explanation of the clinical purpose of CPT code 78428, how it is used in practice, and the typical sites where the service is delivered. The publication provides benchmarks and comparative policy summaries for major national payers, outlines clinical context for interpretation of results, and highlights common billing considerations. Data gaps from the input are noted where specific taxonomies, ICD-10 pairings, or related codes are not provided. The piece is intended for a national audience of clinicians, coding professionals, and payers seeking clarity on the code’s clinical intent, expected care setting, and payer coverage landscape.