Arrhythmias and conduction defects

Question 1

what are examples of narrow complex arrythmias (not of ventricular origin) (5)

Answer 1

1) sinus tachycardia
2) atrial fibrillation
3) atrial flutter
4) AVNRT (SVT) AVRT due to WPM (SVT)
5) atrial tachycardia

Question 2

what are examples of broad complex arrhtymias?

Answer 2

1) ventricular tachycardia
2) toursades de pointes
3) ventricular fibriallatoin
4) aberrant conduction (SVT + BBB)

Question 3

what is supraventirclaur tachycardia also in a clinical setting?

Answer 3

paroxysmal supraventrual tachycardia (PSVT)

= SVTs that have a sudden onset and are regular and hence excludes sinus tachycardia (gradual onset) and AF (irregular).

therefore the term SVT only considers AVNRT and AVRT.

Question 4

what are exmples of bradyarrythmias?

Answer 4

1) sinus bradycardia
2) atrioventricular block
3) asystole
4) over-controlled fast rhythms.

Question 5

what is the aetiology of arrythmias pneumonic?

Answer 5

HACH PIRATES:

H - hypertension, hypercapnia, hypoxia
A - alcohol
C - cardiomyopathy, constrictive pericarditis

P - pulmonary: PE, pneumonia 
I - Iatrogenic 
R - Rheumatic heart disease 
A - atheresclorotic heard disease : MI, IHD 
T - thyroxitoxocosis 
E - endocarditis
S - sepsis

Question 6

what do you see in an ECG with arrythmias?

Answer 6

absent P waves, rapid irregulalry irregular ventricular rhythm, narrow QRS, f waves may be present as irregular flucatuations.

Question 7

what blood tests would you do?

Answer 7

FBC
U&Es 
cardiac enzymes 
TFT 
(consider echo to look for left atrial enlargement, mitral valve disease)

Question 8

how do you manage an acute AF?

Answer 8

treat precipitating event (alocohol toxcitiy) or associated illness (MI, pneumonia etc)

use Heparin until full assessment of emboli. if risk is high (TIA or past ischaemic stroke) then use warfarin.

1st line = Diatiliazem or Verapamil.
2nd line = digoxin and amioadorone

start full anticoagulation with LMWH to allow option for cardioversion within 48 hours.

Question 9

what do you do if the onset is less than 48 hours?

Answer 9

• heparin
• tranthoracic echo
• electrical or chemical cardioversion
• if confirmed that onset of AF is < 48 hours then no further anticoagulation is needed.

Question 10

what do you do if the onset is more than 48 hours?

Answer 10

• 4 weeks amioadore or solotol
• 3 weeks anticoagulation
• electrical cardioversion
• 3 weeks anticoagulation

Question 11

when is rate control indicated in pateints?

Answer 11

in pateints over 65 years
had AF for a long time and has caused structural changes.
have a history of IHD.

1st line = beta blockers or caclium channel blockers

2nd line = digoxin = 1st line in coextiing heart fialure / sedentry elderly not as effective as 2 or 4 since it is poor at controlling heart rate.

3rd = (amiodarone) used if other drugs ineffective or contraindicated e.g hypotension.

Question 12

when is rhythm control indicated

Answer 12

non-invasive cardioversion. 
below 65 years. 
symptomatic 
presenting with CCF
presenting with lone AF.

Question 13

what are the drugs used in rhythm control?

Answer 13

amiodarone and stalol for mainetance.

Flecainide is 1st choice in those with no structural heart disease. (bad drug for bad heart)

Question 14

when is ablation done?

Answer 14

when rhtym control is desired by cannot be maintained by medication or cardioversion.
it can be used for all forms of SVT.

anticoagultate with warfarin (aspirin in < 65 years or lone AF or if warfarin is contraindicated.

Question 15

what scoring system is the CHA2D S2VAS for?

Answer 15

for risk of stroke.

Question 16

what does the CHA2D S2VAS stand for?

Answer 16

for risk of stroke.

C - congestive heart failure 
H - hyeprtension 
A - age > 75 years 
D - diabetes mellitus 
S2 - stroke 
V - vascular disease 
A - age 65-75 
Sex - females are at greater risk

score of 0 - they are at low risk so give nothing or aspirin
score of 1 - moderate give aspirin or warfarin
score of >2 - high risk so give warfarin.

Question 17

what is a common complication of A fibrillation?

Answer 17

thromboembolism

Question 18

what is atrial flutter?

Answer 18

abnormal heart rhythm that occurs in the atira of the heart. a single re-entry circuit forms in the left atrium.
ventricular response depends ona. degree of block in the AVN. of then the atira contract with the rate of almost exactly 300bpm and commonly there is 2:1 block. hence one should always consider atrial flutter in a regular narrow complex tachycardia with a rate of 150 bpm.

Question 19

what are the clincial features of A flutter?

Answer 19

1. chest pain
2. dysponea
   3, palpitations
3. regular pulse

Question 20

what do you see in an ECG fro atrial flutter?

Answer 20

rapid, regular rhythm
sawtooth F waves in leads I, II, AvF and positivien in lead V1 only if 3:1 block (carotid sinus massage may be necessary to elecit this)
p waves difficult to see if 2:1

Question 21

what is the management of a flutter?

Answer 21

DC cardioversion is more effective than chemical cardioverison.

2. chemical cardioversion (amiadrone, sotalol, fleaimide)
3. regular atrial flutter is treated with cavotricuspid ablation.