In simple words: This procedure involves inserting catheters into the heart and blood vessels to examine the heart, coronary bypass grafts, and blood flow. Medication is given to affect blood flow, and measurements are taken to assess the heart's function and blood vessel health.

This code represents a combined procedure involving right and left heart catheterization, angiography of one or more coronary artery bypass grafts (internal mammary, free arterial, or venous), and administration of a pharmacologic agent (e.g., nitric oxide, nitroprusside, dobutamine, milrinone) with hemodynamic assessment before, during, and after agent administration.

Example 1: A patient with a history of coronary artery bypass surgery presents with chest pain. C7553 is used to evaluate the patency of the bypass grafts and assess overall heart function by performing right and left heart catheterization and angiography of the bypass grafts, while also administering a vasodilator and monitoring the hemodynamic response., A patient with suspected heart failure who has undergone prior bypass surgery requires assessment of cardiac function and bypass graft patency. C7553 is used to perform right and left heart catheterization, including left ventriculography to evaluate the heart's pumping ability, along with angiography of the bypass grafts to visualize blood flow, administering a medication to see how the heart and vessels respond., A patient with recurrent angina after bypass surgery needs to be evaluated for potential blockages in the grafts. C7553 is performed to visualize the bypass grafts using angiography, assess the function of the heart using right and left heart catheterization, and administer a vasodilator under close hemodynamic monitoring to observe changes in blood flow and pressure.

Documentation should include details of the catheter placements, angiography findings, administered pharmacologic agent and dosage, hemodynamic measurements, and the physician's interpretation of the findings.