Pacing

Question 1

where are pace makers implanted

Answer 1

subclavian region on L or R (depending on whether R or L handed

Question 2

in what pacemaker type are the spikes not regular (i.e. sometimes intermittent or absent)? why?

Answer 2

demand pacemaker
occurs if pts HR is above the threshold for pacing on its own
(pacemaker only initiates a beat if the heart does not beat fast enough)

Question 3

types of pacemaker

Answer 3

unipolar vs dual chamber (has atrial and ventricular leads)

fixed rate (synchronous) vs on demand (asynchronous)
(on demand = only initiates a beat if heart doesn't do it on it's own)

Question 4

which diseases for:

a) atrial lead only
b) RV lead only
c) dual lead

Answer 4

atrial lead -> sinoatrial disease in young ppl with good AV node conduction (older pts are more likely to develop AV block and so need dual chamber)
RV lead - permanent atrial fib
dual lead - all other scenarios!

Question 5

what is an ICD

Answer 5

implantable cardioverter defibrillator

implanted like a pacemaker

Question 6

what do ICDs do? for what rhythms?

Answer 6

deliver internal defib in response to VF or VT

Question 7

how can the pts who have ICDs be classified

Answer 7

those who have it for primary prevention vs those who have it for secondary

Question 8

when is an ICD used for secondary prevention

Answer 8

• previous MI due to VT/VF
• sustained VT with syncope or haemodynamic compromise OR LVEF <35%

-both above have to have no other treatable cause e.g. occluded artery

Question 9

when is an ICD used for primary prevention

Answer 9

those who are at risk of serious ventricular arrhythmia:

• FHx: hypertrophic cardiomyopathy, brugada, long QT syndrome
• previous surgical repair of congenital <3 dis
• previous MI, LVEF <35% and HF sx

Question 10

indications for pacing

Answer 10

SAMBuCA (need to pace yourself when you drink it…)
Stokes Adams
AF
Mobitz type two (tU)
Bradycardia (persistent and symptomatic)
cardiomyopathy (dilated, hypertrophic obstructive)
AV block post anterior MI