Resynchronisation and Cardioversion

Question 1

Heart Failure Classification

Answer 1

1 - cardiac disease but no symptoms
2 - mild symptoms, mild activity limitation
3 - comfortable only at rest
4 - not comfortable at rest

Question 2

Normal cardiac electrical pathway

Answer 2

SAN => Bachman bundle to LA, internodal pathways in RA => AVN

AVN => BofH => L&R bundle branch => PF

Question 3

1st degree AV block

Answer 3

Long PR 0.2s+

Benign finding - asymptomatic

Question 4

2nd degree AV Mobitz 1

2nd degree AV Mobitz 2

Answer 4

Pace if symptomatic

PR gets longer until QRS droppped

PR fixed but QRS dropped at predictable intervals - more serious which may progress to complete HB
-AVN, His Pukinje issue

Question 5

Complete HB

Answer 5

No relationship between P and QRS
P and QRS intervals are regular
-QRS escape rhythms broader due to slower activation of ventricles

Question 6

How to pace

Answer 6

Via subclavian vein - more anterior

Pacemaker leads in
-RA appendage
-RV apex
Attached into heart wall with screw

If veins blocked/used, high infection risk => can use leadless PM via IVC

Question 7

Bundle branch block

Answer 7

Issue with bundle branches => dysynchrony of ventricular contraction
-electrical activity will flow from the unaffected side => affected side

Can also occur if you insert PM wire into RV => dysynchrony between ventricles = L BBB

Question 8

VT and VF

Answer 8

Life threatening ventricular arrythmias

• ischemia
• cardiomyopathy
• drugs (QT prolonging)
• electrolyte disturbances (K abnormalities)
• congenital cardiac abnormality

Question 9

VF

Answer 9

No ventricular coordination => ventricular fibrillation

No CO => collapse
NEEDS CARDIOVERSION ASAP

Question 10

VT

Answer 10

Can turn to VF

Slow VT can be asymptomatic as there is some CO
Fast VT - chest pain, collapse, death

Question 11

Primary and secondary prevention of sudden cardiac death

Answer 11

Drugs
Lifestyle modification - smoking is the main one
Cardiac devices
Heart transplant

More effective in secondary cardiac prevention, more likely to have another event

Question 12

ICD

Answer 12

Higher voltage used
Lead to RV

Can be SC - lead is substernal

Question 13

CRT

• who benefits
• who would you do this in

Answer 13

Cardiac resynchronisation therapy

• LVEF U35%
• LBBB
• Broad QRS
• HF symptoms

Lead in RA, RV
Via coronary sinus => enter vein that overlies LV and place 3rd lead here