•Pacemaker
Easily identified by the battery unit placed in the chest
When in doubt, check the patient, you can usually feel (if not see) the “box” in the “surgical pocket” of the chest.
ProTip (Advanced): Pacemakers can be atrial pacing, ventricular pacing, or both. You’ll see a lead deep in the right ventricle (always). You might seen an additional lead in the atria as well (for atrial pacing).
The device will always tell “the band” (the ventricle) when to play (contract)
The device might also try to just tell “the conductor” (SA node) how to keep pace (like a metronome) – that’s atrial pacing.
•Sternotomy Wires
Anyone who has had “open heart surgery” will have had to have their sternum cut. This is “tied” back together with wires (apparent on imaging). The wires are left in place even after healing.
•IVC Filter
Pt’s who have a huge DVT and are at risk for PE (or already have a PE, and US shows a lot of “clot burden” remaining in the leg), a filter might be placed in the IVC.
It’s designed to “capture clots” before they make it to the lungs
Important Point: Ironically, the filter is thrombogenic itself and should be removed (they are built now to be removable).
Patient’s often forget this, and IVC filters stay in far too long
•Cardiac Valve Replacement
Mechanical (as opposed to tissue) valve replacements will have metallic components that are visible on imaging
Valves come in many different types (valve types are beyond the scope of this course)
•Endotracheal Tubes
Seen only on ventilated patients
On imaging: You’ll notice a tube in the trachea
All patients on a vent have a protocol to image the chest to make sure the tube hasn’t migrated
Goal is 2cm above the Corina
The concern: the tube will migrate down into one bronchus and we will only be supporting that lung
Technically, you can place a tube in each main bronchus, connect them to separate ventilators and operate each independently
(I’ve seen this only once in my entire career)
•ProTip:
•On CT imaging, a “tube within a tube” is an ETT tube (air within the EET tube is the same signal, black, as the air within the trachea, black)
•Recall: The lungs are both full of air (also black), and the trachea is found between them.
•Chest tubes
Frequently placed to help remove air or fluid from the pleural cavity
Tube can be strait, or curled (a “pigtail catheter”)
•Permanent Pacemaker (PPM) vs (ICD)
An ICD can be identified by the shock coil (thick white section on the lead)
Pacemakers a placed to keep pace. ICD’s are placed to shock hearts out of deadly arrhythmias
•Pacemaker Pathology?
A consideration before placing a pacemaker in a patient, is their mental status.
It takes time for the leads to be epithelialized and firmly attached to the vessels they run through.
Until that time, the leads can “move” (the doctor term is “migrate”)
Dementia patients (who tend to be older and at risk for needing a pacemaker), may “forget” about the device, and just feel the battery unit (the “box”) in their chest.
They can “fiddle” with it, and move the device underneath the skin
If rotated just right, the patient can “wind” the leads out of the heart and back toward the box. This makes the pacemaker useless.
•Pacemaker Pathology?
“Twiddler’s Syndrome”
(I have seen this in actual practice)
Notice the leads wrapped around the battery unit
Notice the lead is now nowhere near the right ventricle (or the heart for that matter)
