Ventricular Tachycardia

Question 1

def

Answer 1

a fast heart rhythm that begins in the ventricles
defined as >100bpm with at least three irregular heartbeats (wide QRSs) in a row
due to malfunction in hearts electrical conduction

Question 2

aetiology

Answer 2

abnormal electrical conduction

triggered by:
1 IHD
2 HF
3 cardiomyopathy
4 MI
5 aortic stenosis

Question 3

epi/risk factors

Answer 3

older
heart condition
previous MI
family history of VT

Question 4

history

Answer 4

1 dizziness/syncope
2 chest pain/palpitations
3 SOB

Question 5

examination

Answer 5

1 tachycardia + tachypnoea
2 hypotension
3 reduced consciousness
4 raised JVP

Question 6

what are the different ways in which ventricular tachycardia are classified

Answer 6

1 duration (length of episode)
2 morphology (heartbeat pattern)
3 hemodynamic effect (effect on the hearts abillity to pump blood)

Question 7

what are the different types of ventricular tachycardias?

Answer 7

1 nonsustained (short, stops spontaneously, no effect on blood flow)
2 sustained (longer than 30s, causes decreased blood flow)
3 monomorphic (heartbeats are similar)
4 polymorphic (heartbeats vary)

Question 8

investigations

Answer 8

1 ECG
2 Cardiac MRI
-observe heart structure
3 TOE
observe heart structure + valves

Question 9

management

Answer 9

treatment is aimed at either stopping current episode or preventing future episodes

stopping current episode
1 cardioversion for presence of pulse
2 defibrillation for pulseless VT
preventing future episodes
1 medication
-stable monomorphic waveform, medications include procainamide or sotalol
-low Mg may be cause of VT, therefore give Mg if low
-long-term anti-arrhythmic therapy
2 surgery
-ICD more effective than drug therapy for prevention of sudden cardiac death due to VT + VF
-cardiac ablation in recurrent VT

Question 10

complications

Answer 10

1 VF
2 cardiac arrest
3 death
4 syncope

Question 11

prognosis

Answer 11

best predictor of prognosis is LF function

patients with other cardiac disease have poorer prognosis than idiopathic VT

Question 12

what makes it mort likely for a wide complex tachycardia to be a VT

Answer 12

MI
CCF
recent angina

Question 13

what ECG findings would support VT

Answer 13

1 positive QRS concordance in chest leads
2 LAD
3 AV dissociation or 2:1 or 3:1 block

Question 14

what is prognosis of VT best predicted by

Answer 14

LV function

Question 15

what are the signs + symptoms of hemodynamically unstable VT

Answer 15

insufficient oxygen supply
1 chest pain
2 SOB
3 hypotension
4 altered consciousness

Question 16

how is hemodynamically unstable monomorphic VT treated

Answer 16

synchronized DC cardioversion

Question 17

how is hemodynamically unstable polymorphic VT treated

Answer 17

defibrillation

Question 18

how are hemodynamically stable patients treated

Answer 18

treatment depends on whether VT is monomorphic or polymorphic and whether LV function is impaired

Question 19

how is hemodynamically stable monomorphic VT with normal LV function treated

Answer 19

restoration of sinus rhythm

IV procainamide or sotalol or lidocaine

Question 20

how is hemodynamically stable monomorphic VT with impaired LV function treated

Answer 20

amiodarone/lidocaine preferred as procainamide can exacerbate HF