Pacemakers & ICDs

Question 1

What is a pacemaker?

Answer 1

Device that applies electrical stimulation to the heart to initiate depolarisations and contractions at desired rate

Question 2

What are the two types of pacemakers based on location?

Answer 2

Single-chamber or dual-chamber pacemakers

Question 3

What are the indications for a permanent pacemaker?

Answer 3

Symptomatic or potentially life-threatening bradycardia such as:
* Sick sinus syndrome
* Atrial fibrillation
* AV block

Question 4

What are the indications for a temporary pacemaker?

Answer 4

Short-term use during hospitalisation until arrhythmia resolves or permanent pacemaker can be implanted

Question 5

How are pacemakers fitted by transvenous implantation?

Answer 5

1. Cut just below the collarbone
2. Insert pacing leads into vein
3. Guide leads to correct chamber using X-ray
4. Connect leads to pacemaker fitted in chest pocket

Question 6

What is the common anaesthetic used for transvenous implantation?

Answer 6

Local anaesthetic

Question 7

What are the indications for using transvenous implantation?

Answer 7

More commonly used approach

Question 8

How are pacemakers fitted by epicardial implantation?

Answer 8

1. Attach pacing leads to the outer surface of the heart through an abdominal cut
2. Connect pacing lead to epicardium
3. Attach other end to pacemaker box in abdomen pocket

Question 9

What anaesthetic is used for epicardial implantation?

Answer 9

General anaesthetic

Question 10

What are the indications for epicardial implantation?

Answer 10

Children and people who have heart surgery at the same time as pacemaker implantation

Question 11

How are temporary pacemakers fitted?

Answer 11

Fitted by transvenous or epicardial implantation, but the pacemaker remains outside the body

Question 12

What is an Implanted Cardioverter Defibrillator (ICD)?

Answer 12

Device placed under the skin that delivers a shock when it senses a potentially fatal abnormal heart rhythm, or helps maintain normal rhythm.

Question 13

How does an ICD monitor heart rhythm?

Answer 13

ICD constantly monitors heart rhythm.

Question 14

What does an ICD do when it senses a dangerously fast rhythm?

Answer 14

Delivers a small burst of high-energy charge to heart, which resets heart conduction system.

Question 15

What is the purpose of pacing therapy in an ICD?

Answer 15

ICD delivers a small burst of low-energy charge to heart, to help heart beat at normal rate and rhythm.

Question 16

What steps are involved in implanting an ICD?

Answer 16

1. Patient is sedated or given general anaesthetic
2. Pocket is created under skin to place generator, then leads are guided with fluoroscopy
3. Insertion is either subcutaneous or transvenous
4. Procedure lasts 3-4 hours.

Question 17

What is a Subcutaneous ICD?

Answer 17

Pulse generator placed just under skin and an electrode remains outside the chest wall but near the heart.

Question 18

What is a Transvenous ICD?

Answer 18

Pulse generator implanted under skin and leads run through blood vessels to position on heart surface or inside heart.

Question 19

What are the indications for ICD use?

Answer 19

Patients at high risk of SCD, including:
* Ventricular tachycardia
* Cardiomyopathies
* After cardiac arrest.

Question 20

What is Cardiac Resynchronisation Therapy (CRT)?

Answer 20

Device used to treat heart failure, by inserting electrodes into both ventricles and right atrium.

Question 21

What is a CRT defibrillator (CRT-D)?

Answer 21

Defibrillator for patients with heart failure that delivers multiple shocks to help ventricles beat in tandem, contains a defibrillator and a pacemaker.

Question 22

What is a CRT pacemaker (CRT-P)?

Answer 22

Pacemaker for patient with heart failure that doesn’t have defibrillating ability.