Pacemaker Flashcards
Types of pacemakers.
Percussion pacing - fist strikes to the precordium, used only in periarrest situations.
Transcutaneous pacing - electrical stimulation via defibrillator pads
Temporary transvenous pacing
Subcutaneously implanted permanent pacemaker
Indications for temporary cardiac pacing.
Symptomatic bradycardia unresponsive to atropine.
After acute anterior MI, prophylaxis for;
Complete HB
Mobitz type I
Mobitz type II
Bi/trifascicular blocks
After inferior MI
Suppression of drug-resistant tachyarrhythmias
During surgery
Indications for a permanent pacemaker (PPM).
Complete HB
Mobitz type II
Peristent AV block after anterior MI
Symptomatic bradycardias like sick sinus syndrome
Herat failure
Drug-resistant tachyarrhythmias
Pre-operative assessment of PPM.
Bloods - FBC, clotting screen and renal function
IV cannula
Consent
Antibiotics
Post-operative management of PPM.
Check wound for bleed or haematoma.
Check leads positions and for pneumothorax on CXR
Check pacemaker function
Driving rules as well
What is cardiac resynchronisation therapy?
Improves the synchronisation of cardiac contraction and reduces mrotality in peple with symptomatic heart failure who have an ejection fraction <35% and a QRS duration > 120ms.
This might be combined with a defibrillator.
What is a fusion beat?
Union of native depolarisation and pacemaker impulse
What is a pseudofusion beat?
Pacemaker impulse occurs just after native depolarisation rendering it ineffective.
What is a pseudopseudofusion beat?
If a DVI pacemaker gives an atrial spike within a native QRS complex, the atrial output is non-contributory.
What is pacemaker syndrome?
IN single-chamber pacing, retrograde conduction to the atria, which then contract during ventricular systole.
THis leads to retrograde flow in pulmonary veins, and reduction in CO, dyspnoea, palpitations, malaise and even syncope.
What will an ECG show with a pacemaker?
What types of pacemakers (chambers) are there?
Single chamber
Dual chamber
Triple chamber
Explain single chamber pacemaker.
Single-chamber pacemakers have leads in a single chamber, either in the right atrium or the right ventricle.
They are placed in the right atrium if the AV conduction in the patient is normal and the issue is with the SA node. This way they stimulate depolarisation in the right atrium and this electrical activity then passes to the left atrium and through the AV node to the ventricles in the normal way.
They are placed in the right ventricle if the AV conduction in the patient is abnormal and they stimulate the ventricles directly.
Explain dual chamber pacemaker
Both RA and RV
Explain triple chamber pacemaker.
RA + RV + LV
Usually in patients with heart failure
These are also called CRT pacemakers
