PPM and ICDs Flashcards
What veins are leads usually placed?
Subclavian, axillary, or proximal cephalic veins
Where are leadless pacemakers placed?
Usually fixed in the RV along the interventricular septum
What can leadless pacemakers pace and how long do they last?
They can only pace the ventricle; battery life is 7-10 years after which another can be placed with or without extraction of the previous device
Where do atrial pacing leads implant? RV leads?
Atrial pacing = right atrial appendage; RV = interventricular septum near the apex
What are indications for PPM placement?
Sinus nodse dysfunction (most common cause requiring pacing) + AV node disease + syncope (neurocardiogenic and hypersensitive carotid sinus) + long QT syndrome + hypertrophic CM
What are indications for leadless pacemakers? What is the most common indication?
Standard indications for ventricular-only pacing (VVI); permanent atrial fibrillation (most common reason) + complete heart block in patients > 70yo with limited function + sinus node dysfunction with intermittent pacing needs + prior device infections/multiple risk factors for infection + vascular access issues
What is the 5th position for a pacemaker code?
Anti-tachycardia function (ICD capability); 0 = none, P = pace, S = shock, D = dual (pace and shock)
When would you need a DDI pacemaker?
Dual chamber pacing in setting of SVTs (most devices are actually DD and will switch to DDI when sensing pathological atrial rhythms)
What are common complications for dual chamber pacemakers?
Lead dislodgement (4.2%) > inadequate sensing (2.2%) > pneumothorax (1.8%) > inadequate pacing (1.3%)
What are common complications for ventricular pacemakers?
Pneumothorax = lead dislodgement (1.4%) > others
What are some long-term complications for devices?
Tricuspid regurgitation + tachycardia-induced cardiomyopathy (from RV pacing) + venous obstruction + endocarditis + lead failure + dislodgement
What is pacemaker syndrome?
Long-term clinical heart failure syndrome with reduced cardiac output due to suboptimal AV synchrony
How is an LV lead placed for CRT?
Usually placed through the coronary sinus
What are class I indications (recommended) for CRT?
EF < 35% with sinus rhythm and LBBB with NYHA class II or worse
What are class IIa indications (can be useful) for CRT?
EF < 35% with sinus rhythm and non-LBBB QRS widening and NYHA class III-IV OR EF <35% with a. fib requiring V-pacing/rate control/ablation allowing for near 100% V-pacing
What are class IIb indications (might be useful) for CRT?
Ischemic EF < 35% with sinus rhythm and LBBB with NYHA class I or worse OR EF <35% with sinus rhythm and non-LBBB QRS widening with NYHA class II or worse (if QRS is less wide, needs to be NYHA III or IV)
What is the difference between a CRT-D and CRT-P device?
CRT-D has the ability to defibrilation (ICD lead placed); CRT-P is only a pacemaker
Where are ICD leads placed in the heart?
A single coil lead is implanted into the RV; You can also have a dual coil lead that has both an SVC and RV coil
How do subcutaneous ICDs work?
An 8cm shock coil is placed just left of sternal midline that contains 2 sensing electrodes on each end; the generator is placed at the left mid-axillary region which also has a sensing electrode
Can subcutaneous ICDs pace?
They do not have standard pacing functionality but they can be programmed to demand pace for up to 30 seconds at 50 bpm after a shock
What are the indications for primary prevention with ICD?
Ischemic cardiomyopathy (LVEF < 35% and NYHA class II/III or LVEF < 30% and NYHA class I) + Non-ischemic CM (LVEF < 35% with NYHA class II/III) + arrhythmogenic RV dysplasia + hypertrophic CM + long QT syndrome + noncompaction of the LV
What are the indications for secondary prevention with ICD?
Symptomatic VT and VF without reversible cause + stable or unstable VT with structural heart disease (i.e. arrhythmogenic RV dysplasia, infiltrative CM (sarcoid, giant cell, Chagas), hypertrophic CM) + Brugada syndrome with syncope or VT + ischemic CM with LVEF < 40% and inducible NSVT
What are indications for subcutaneous ICD placements?
- Requires ICD for primary or secondary prevention
- No need for pacing therapy
- One or more risk factors for problems with transvenous leads (young age, high infection risk, difficult venous access)
- Passed electrical screening for S-ICD
What do you need to worry about with ICD placements in terms of anesthetic plan?
The anesthetic is the same as for PPMs except for during defibrillator threshold testing (DFT) where you need deep sedation
What type of anesthetic should you use for subcutaneous ICD placements?
Usually require GA as there is quite a bit of tunneling which cannot be covered with local alone; can also do a serratus anterior plane block
