Written by Chris Thom
Spoon Feed
POCUS can help with placement of emergent transvenous pacers and should be used for guidance of the pacer wire and for troubleshooting.
Incorporate POCUS when it’s time to pace
This was a case series of ED-performed transvenous pacemakers (TVPs) on critically ill patients, followed by a narrative review of the use of POCUS in TVP placement. In each of the two presented cases, the pacer wire was advanced until electrical capture would have been anticipated. However, the wire had been malpositioned in both cases, with one curled in the right atrium (RA), while the other traversed into the subclavian vein. Using POCUS, the clinician was able to identify the exact location of the malpositioned catheter, perform repositioning under POCUS guidance, and achieve successful capture. If resources allow, have a dedicated clinician for POCUS during TVP placement. Following introducer catheter placement in the IJ, agitated saline can be injected to confirm venous placement via the presence of agitated saline in the R heart on POCUS. The subcostal or apical four-chamber view can then be obtained while the pacer wire is advanced. If the pacer wire gets to 30 cm of depth without successful visualization of the wire on POCUS, interrogate the inferior vena cava, subclavian veins, and contralateral IJ to find the wire. If the wire inappropriately curls in the RA, retract it and re-insert, and consider applying a leftward curvature to the wire and then re-advancing.
How does this change my practice?
In the ED environment, fluoroscopy-guided TVP options are a rarity. We tend to rely on anatomical landmarks and interpretation of electrical activity to determine pacer wire placement, but there is a better way. POCUS can serve much the same purpose as fluoroscopy and provides imaging guidance even without a cardiologist and fluoroscopy table. I agree with the authors that if you have the personnel, put a dedicated clinician on POCUS for the TVP placement.
POCUS pro-tips and clips:
Agitated saline is a useful trick and easy to use. A three-way stopcock can be used to pass saline back and forth between a full syringe and an empty one. This will cause the small aliquot of air to disperse into microbubbles, which makes it easy to see on POCUS. It is useful in central line confirmation and can serve the role of confirming venous placement of your introducer sheath with TVP. The pacer wire will be highly echogenic and often has an associated reverberation artifact. You can visualize the RA/RV on the subcostal or apical four chamber window. You can also often get a clear view of the RA/RV on the parasternal long view when tipping the probe caudal towards the toes (see this clip for a normal PSLA view with tricuspid valve visible).
Source
Troubleshooting Transvenous Pacemakers with Point of Care Ultrasound (POCUS). POCUS J. 2025 Apr 15;10(1):53-60. doi: 10.24908/pocusj.v10i01.18073. PMID: 40342676
