Arrhythmias and conduction defects Flashcards
what are examples of narrow complex arrythmias (not of ventricular origin) (5)
1) sinus tachycardia
2) atrial fibrillation
3) atrial flutter
4) AVNRT (SVT) AVRT due to WPM (SVT)
5) atrial tachycardia
what are examples of broad complex arrhtymias?
1) ventricular tachycardia
2) toursades de pointes
3) ventricular fibriallatoin
4) aberrant conduction (SVT + BBB)
what is supraventirclaur tachycardia also in a clinical setting?
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.
what are exmples of bradyarrythmias?
1) sinus bradycardia
2) atrioventricular block
3) asystole
4) over-controlled fast rhythms.
what is the aetiology of arrythmias pneumonic?
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
what do you see in an ECG with arrythmias?
absent P waves, rapid irregulalry irregular ventricular rhythm, narrow QRS, f waves may be present as irregular flucatuations.
what blood tests would you do?
FBC U&Es cardiac enzymes TFT (consider echo to look for left atrial enlargement, mitral valve disease)
how do you manage an acute AF?
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.
what do you do if the onset is less than 48 hours?
- heparin
- tranthoracic echo
- electrical or chemical cardioversion
- if confirmed that onset of AF is < 48 hours then no further anticoagulation is needed.
what do you do if the onset is more than 48 hours?
- 4 weeks amioadore or solotol
- 3 weeks anticoagulation
- electrical cardioversion
- 3 weeks anticoagulation
when is rate control indicated in pateints?
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.
when is rhythm control indicated
non-invasive cardioversion. below 65 years. symptomatic presenting with CCF presenting with lone AF.
what are the drugs used in rhythm control?
amiodarone and stalol for mainetance.
Flecainide is 1st choice in those with no structural heart disease. (bad drug for bad heart)
when is ablation done?
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.
what scoring system is the CHA2D S2VAS for?
for risk of stroke.
what does the CHA2D S2VAS stand for?
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.
what is a common complication of A fibrillation?
thromboembolism
what is atrial flutter?
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.
what are the clincial features of A flutter?
- chest pain
- dysponea
3, palpitations - regular pulse
what do you see in an ECG fro atrial flutter?
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
what is the management of a flutter?
DC cardioversion is more effective than chemical cardioverison.
- chemical cardioversion (amiadrone, sotalol, fleaimide)
- regular atrial flutter is treated with cavotricuspid ablation.
