ventricular arrhythmias

Question 1

what are the main VAs? 5

Answer 1

ventricular tachyarrhythmias

• torsades des pointes
• ventricular fibrillation
• premature ventricular complex
• asystole

Question 2

what does TdP look like on an ECG?

Answer 2

like VF but it is actually VT with varying axis

• there is a broad QRS complex and continuously changing QRS morphology

Question 3

is the rhythm regular or irregulaar in TdP?

Answer 3

irregular

Question 4

what may be the events leading to TdP?

Answer 4

• hypokalaemia
• prolongation of the action potential (drug induced)
• renal impairment (increased drug levels)

Question 5

what does PVC look like on ecg?

Answer 5

very borad QRS

Question 6

There is a fall in ___ following the ectopic beat - the patient might feel light headed

Answer 6

There is a fall in BP following the ectopic beat - the patient might feel light headed

Question 7

what are some of the causes of PVC?

Answer 7

• Ischaemic heart disease,
• hypertension with left ventricular hypertrophy
• heart failure
• May be marker for inherited arrhythmia syndromes e.g. cardiomyopathy

Question 8

if PVC worse on ______, need to investigate further

Answer 8

If worse on exercise, need to investigate further

Question 9

what drugs are used in the treatment of PVC?

Answer 9

b blockers

Question 10

most patients who get VT have significant heart disease , such as….

Answer 10

• coronary artery disease

- previous MI

Question 11

what are the rare causes of VT?

Answer 11

• cardiomyopathy

- inherited/ familial syndromes

Question 12

give some examples of inherited/familial arrhythmia syndrome that can cause VT?

Answer 12

long QT

brugada syndrome

Question 13

what is the difference between monomorphic and polymorphic VT?

Answer 13

monomorphic - the qrs stay relatively stable

Question 14

why do the QRS stay relatively stable in monomorphic VT?

Answer 14

each ventricular impulse is being generated from the same place in the ventricles

Question 15

monomorphic VT is usually due to ______

Answer 15

scarring

Question 16

polymorphic VT is usually due to ______ _ _______

Answer 16

TdP

Question 17

what is VF?

Answer 17

a chaotic ventricular electrical activity which causes the heart to lose the ability to function as a pump

Question 18

what is the treatment for VF?

Answer 18

• DC cardioversion

- cardiopulmonary resuscitation

Question 19

what is the abnormilty in conduction in brugada syndrome?

Answer 19

there are faulty sodium channels which predispose to fatal arrhythmias

Question 20

which group of people typically get brugada?

Answer 20

young males

Question 21

what can trigger brugada?

Answer 21

fever

Question 22

how do you prevent the arrhythmias caused by brugada if you know someone has it?

Answer 22

ICD

Question 23

how do you manage acute long QT syndrome?

Answer 23

• correct any electrolyte disturbance
• stop causative drugs
• heart rate maintaed with atrial or ventricular pacing
• IV isoprenaline when QT prolongation is acquired

Question 24

when do you not use isoprenaline in treatment of long QT?

Answer 24

when QT prolongation is congenital

Question 25

what is the long term management of long QT?

Answer 25

- beta blockers - left cardiac sympathetic denervation - pacemaker therapy

Question 26

what are the causes of VT and VF?

Answer 26

- mainly due to structural heart disease | - can be primary electrical disease though

Question 27

what is the treatment for acute VT?

Answer 27

- dc cardioversion if unstable acute CV only if it is an emergency - if stable consider pharmcologic cardioversion with AAD - consider adenosine to make a diagnosis

Question 28

what may be the causes of VT?

Answer 28

- electrolyte- hypokalaemia hypomagnesaemia - ischaemia - hypoxia - medications that prolong the QT interval

Question 29

which medications may prolong the QT interval?

Answer 29

sotalol. quinidine, terfenadine, erythromycin, digoxin

Question 30

what are the treatment steps according to cheese and onion? part 1

Answer 30

- Give high-flow oxygen by face mask. - Obtain IV access. Send U&E, cardiac enzymes, Ca2+, Mg2+. Correct low K+or Mg2+. - Obtain 12-lead ECG. - ABG (if evidence of pulmonary oedema, reduced conscious level, sepsis). - Amiodarone IVI. Phlebitis may result if peripheral line used, especially if concentration >2mg/mL. Rarely, lidocaine 50mg over 2min instead, followed by infusion; see BNF.

Question 31

what are the treatment steps according to cheese and onion? part 2

Answer 31

If polymorphic (torsade de pointes) magnesium sulphate 2g over 5min. If this fails, or if cardiac arrest, use DC shock (p806 and inside back cover). After correction of VT, establish the cause from history/investigations. Maintenance antiarrhythmic therapy may be required, eg amiodarone. Prevention of recurrent VT: implantation of automatic defibrillators (ICD) may help. In refractory cases radiofrequency ventricular tachycardia ablation may be tried.

Question 32

what is the treatment of VT long term?

Answer 32

- correct ischaemia - revascularisation | - ICD if life threatening

Question 33

what is the indication for AADs in VT long term-

Answer 33

not so great

Question 34

what is the function of ICD in the ventricle?

Answer 34

VT prevention, antitachycardia pacing, cardioversion, defibrillation

Question 35

what is the function of ICD in the ventricle and atria ?

Answer 35

bradycardia sensing | bradycardia pacing