Implanted pacemaker failure
| see below for possible presentations | |
|---|---|
| History | - What device? Why implanted? - Pt's intrinsic rhythm/rate? - Appropriate pacing and sensing? Indication may be for bradycardia, tachycardia (VT) or heart failure (CRT-D/CRT-P) |
| Examination | May present with - inappropriate shocks while conscious - acute heart failure - signs of ischaemia - syncope |
| Diagnostic investigations | Rhythm strip + 12 lead ECG (although may not be diagnostic) CXR - lead fracture? |
| Differentials | Underlying cause - device may be sensing Unstable tachyarrhythmias? - acute coronary syndrome causing monomorphic VT - acute heart failure - lead fracture |
| Immediate management | Backup plan: Transcutaneous pacing, atropine, isoprenaline, adrenaline etc. Address the underlying cause of arrhythmia: K, Mg... |
| Ongoing management | Interrogate device ASAP → any therapies delivered? |
lead failure
- lead fracture
- lead migration
device failure
- Problems with sensing
- undersensing = asynchronous pacing
- pacing spikes within QRS complexes
- oversensing = electrical activity inappropriately recognised as cardiac activity
- large P/T waves
- undersensing = asynchronous pacing
- Problems with pacing → won't be seen if native HR > threshold
- failure to capture
- pacing spikes without following electrical capture on ECG
- failure to capture
- Pacemaker-mediated tachycardia = re-entry tachycardia
pocket failure
which sounds very cute but just refers to problems with where the PPM sits
- may need revision or re-siting
Implantable cardioverter defibrillator - ICD
On CXR, has thick coil wrapped around inner core
- Anti-bradycardia pacing
- Anti-tachycardia pacing (ATP)
- Defibrillation
"ICD storm" = repeated defibrillation
- very unpleasant!!
- appropriate? → patient in VF/VT → invstigate for tachyarrhythmia
- electrolytes
- ECG + comparison to old ECGs; troponin?
- inappropriate? → lead fracture, misidentification of rhythm