Permament Pacemaker (Complete*)

Question 1

What are the main indications for permament pacemaker?

Answer 1

Complete heart block

Mobitz type II AV block

Cardiac resynchronisation therapy (severe HF EF<35%)

Symptomatic mobitz type I

Symptomatic sick sinus syndrome

Permament bradyarrhythmias following MI

• Typically more likely to occur with anterior MI and typically transient with others

Question 2

Where are pacemakers typically inserted?

Answer 2

Subclavian region in pre-pectoral pocket

Leads inserted in cephalic or subclavian vein

N.B. Typically done under local anaesthetic

Question 3

What are the main complications of pacemaker insertion?

Answer 3

Pneumothorax

Haemothorax

Heart perforation

Thromboembolism

Infection

Question 4

What are the types of leads that are placed in pacemakers?

Answer 4

Right atrial lead

• Passed through right atrial appendage during insertion

Right ventricle lead

• Placed at right ventricle apex or ventricular septum

Left ventricle lead

• Placed into coronary sinus veins

Question 5

What are the three main types of pacemakers?

Answer 5

Single chamber pacemaker

• One lead (either R atrium or R ventricle)

Dual chamber (most common)

• Two leads (r atrium and R ventricle)

Biventricular pacemaker (aka cardiac resynchronisation therapy)

• Three leads ( R atrium, R ventricle, L ventricle)

Question 6

Which is the most commonly inserted pacemaker?

Answer 6

Dual chamber pacemaker

N.B. Mimics heart electrophysiology better than single chamber

Question 7

When is single chamber pacemaker indicated?

Answer 7

Young patients with SA node dysfunction (Single RA lead)

• Tend to have healthy AV nodes

Some patients with permament AF (Single RV lead)

Question 8

When is biventricular cardiac pacemaking indicated?

Answer 8

Used in cardiac resynchronisation therapy

Question 9

What ECG findings are indicative of atrial pacing?

Answer 9

Spike before P wave

Question 10

What ECG findings are indicative of ventricular pacing?

Answer 10

Pacing spike precedes the QRS complex.

ST segments and T waves discordant with the QRS complex

• QRS complex on opposite side of isoelectric line from ST and T wave.

Right ventricle pacing: LBBB

Left ventricle pacing: RBBB

Question 11

What type of bundle branch can appear on ECGs for patients with right ventricular pacing?

Answer 11

LBBB

Question 12

What type of bundle branch can appear on ECGs for patients with left ventricular pacing?

Answer 12

RBBB

Question 13

How does dual chamber pacemaker present on ECG?

Answer 13

Depends on area being paced

Either of the following:

• Both atrial + ventricular spikes
• Only atrial spikes
• Only ventricular spikes

Question 14

What are the main complications of pacemakers?

Answer 14

Infection

Displacement

• E.g. can occur when patients idle play with pacemaker

Fracture/subclavian crush

• Damage to leads due to rubbing together or against the clavicle.

Pacemaker syndrome

Pacemaker mediated tachycardia

Question 15

What is pacemaker syndrome?

Answer 15

Collection of symptoms (e.g. confusion, palpitations, fatigue, SoB, HF symptoms) due to lack of coordination caused by pacemaker

N.B. Most likely to occur with ventricular single chamber pacemakers

Question 16

Pacemaker on ECG

N.B. Right sided leads should be anteriorly located on lateral CXR