A balloon-tipped catheter placed in the coronary sinus is used during cardiac surgery for retrograde cardioplegia and is secured by a purse string suture placed proximal to the atrioventricular groove in the lower right atrium. We report a complication of this procedure where a pulmonary artery catheter was sutured to the wall of the right atrium by the purse string suture in a patient scheduled for aortocoronary bypass grafting. Pulsatile resistance was noted when we attempted to withdraw the catheter indicating an attachment to the heart. The pulmonary artery catheter within the vascular space after atrial cannulation should be checked since the sheath-protected cannula will enable free mobility.