Difficulty in the precise localization by cardiac catheterization of left-to-right shunts near the pulmonary valve.
D006328:Cardiac Catheterization; D018376:Cardiovascular Abnormalities; D002319:Cardiovascular System; D006321:Heart; D006801:Humans; D011664:Pulmonary Valve
CARDIOVASCULAR DEFECTS, CONGENITAL; HEART