Does presence of obstruction in the passage of the pulmonary artery catheter hinder the catheter placement? - obstraction during pulmonary artery palcement

Placement of a PAC by monitoring the pressure waveform is difficult in a patient with history of tricuspid ring annuloplasty and the placement under X-ray fluoroscopic photographing system is recommended. On the other hand, the placement by monitoring the pressure waveform may be available in a patient with transvenous pacemaker leads and pulmonary stenosis.