(Originally presented by Dr Rebecca Landers)
Why is this important?
- High risk procedures
- Out of theatre anaesthesia
- Anaesthetic implications are different for left vs right heart ablations
- We need to understand what is required of us by the Cardiologist
How does it work?
- Re-entrant arrhythmia are amenable to ablation- endocardium is cauterised at the area of re-entry to render it electrically inert
- Choice of catheter and ablation energy varies depending on the pathology and site of re-entry
- EP catheters enter the RA via the femoral or subclavian veins-> may cross the atrial septum by puncturing the foramen oval (usually guided by TOE)
- Catheters create an ‘electrical map’ and specialised software (Carto, NavX) produces 3D reconstructions or cardiac chambers do direct the catheters to the target sites
- Ablation energies include DC ablation (historical), radiofrequency (may include saline irrigation to cool the endocardium), and cryoablation (especially for AF)
Anaesthetic considerations
- Pre-operative
- Right sided lesions= day only
- Left sided lesions (AF)= usually stay in hospital
- Medications
- Antiarrhythmics- withhold
- Anticoagulants- usually continue
- Intra-operative
- Monitoring
- Consider artline if: lengthy, multiple comorbidities, Left sided (require blood sampling and ACT)
- Retrocardiac oesophageal temp probe if ablation of posterior LA wall
- TOE if septal puncture- guides puncture site
- Anticoagulation- heparin if arterial puncture (ACT >300-400sec)
- Post ablation provocation- usually with isoprenaline (guided by Cardiologist)
- LA and sedation vs GA?
- Dependant on patient, duration, if TOE required, if low TV ventilation required
- Note if paroxysmal sympathetically driven tachycardias- inducability may be better if patient awake
- Volatile vs TIVA?
- Doesn’t appear to make a significant difference
- Monitoring
- Post-operative
- Complications may be rapid and catastrophic!
- Mortality after ablation 1 in 1000
- Major complications after SVT ablation 0.8%, AF ablation ~5%, VT ablation !6%
- Included vascular access injuries, septal puncture complications, catheter injury, CVA, phrenic palsy, pericarditis, valve trauma, high grade AV block and coronary spasm
- Complications may be rapid and catastrophic!
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