The Gold Standard for PH Diagnosis
If the results of initial tests point to PH, your doctor will schedule a right-heart catheterization (commonly referred to as a “right heart cath”). Right-heart catheterization is one of the most accurate and useful tests to get a definitive diagnosis for pulmonary hypertension. This is the only test that directly measures the pressure inside the pulmonary arteries, and it should be done in all patients at least once to confirm a patient’s diagnosis of PH. During the test, doctors insert a catheter (a thin rubber tube) through a large vein in the patient’s groin or neck. They then pass the catheter up into the patient’s heart to measure the blood pressure in the right side of the heart and lungs.
Vasodilator Study (Acute Vasodilator Challenge)
This test is used for patients who have already been diagnosed with pulmonary hypertension to determine how much their pulmonary blood vessels can relax over a brief period of time. Its main purpose is to screen for patients who might respond favorably to calcium channel blockers, a form of medication. The test can also help determine the patient’s prognosis. With a right heart catheter in place, the patient is given drugs that relax the pulmonary arteries. The test drug is given to the patient in higher and higher doses, pausing at each dose to see how the patient reacts. Once a significant response occurs or the side effects become intolerable, the test is considered complete.