Arrythmias Flashcards
What is the first line management for unstable tachycardias?
Synchronised DC shocks
Peri arrest, hypotension regardless of broad complex, narrow complex or atrial fibrillation
What’s the treatment for stable patient with a broad complex tachycardia with a regular rhythm?
Loading dose amiodarone followed by 24 hour infusion. (Lidocaine and procainamide are also options)
Regular BCT - Assume ventricular tachycardia unless previously confirmed SVT with bundle branch block.
What’s the management of a stable, broad complex tachycardia with an irregular rhythm?
1) AF with BBB - treat as narrow complex tachycardia
2) polymorphic VT (e.g. Torsade de pointe) - IV magnesium
What’s the management of a stable, narrow complex tachycardia with an irregular rhythm?
Probably AF
1) onset <48 hours electrical or chemical cardioversion
2) >48 anticoagulation and rate control eg B-blocker or digoxin
In which patients should you be wary of when prescribing either B-blockers, flecanide or digoxin?
BB - asthmatics
Flecanide - structural heart problems
Digoxin - renal problems
What’s the management of a stable, narrow complex tachycardia with a regular rhythm?
Vagal manoeuvres followed by IV adenosine
In the management of narrow complex tachycardia with regular rhythms, what dose of adenosine do you give?
Initially 6mg, followed by 12mg, followed by another 12mg
Whats a long QT interval and what can it lead to?
> 430(males) and >450(females)
Causes delayed depolarisation of the ventricals and can lead to VT, sudden collapse or death.
Causes of a long QT interval?
Congenital - Jerrell-Lange-Nielsen syndrome(inc. deafness). Romano-ward syndrome. (No deafness)
Drugs - amiodarone, sotalol, class 1a antiarrthymic drugs, TCA, SSRIS, haloperidone, erythromycin, methadone,
Other - electrolytes, ⬇️K+,⬇️ca2+ ⬇️mg2+, acute MI, myocarditis, hypothermia, Subarachnoid haemorrhage
Signs indicating unstable/ peri-arrest arrthymias
Shock (hypotension <90), pallor, sweating, cold, clammy,confusoin)
Syncope
Myocardial ischaemia
Heart failure
What’s used for pharmacological cardioversion of AF?
Flecanide or amiodarone
Not flecanide in structural or ischemic heart disease.
What are the main 2 types of VT?
Monomorphic- caused by MI
Polymorphic - Long QT precipitates torsades de pointes
What are the main electrolytes causing VT?
Hypokalamia
Hypomagnesiumia
Which AF patients would you NOT cardiovert (rhythm control)?
Those with AF over 48 hours, as clot will likely to have formed and this can cause a stroke.
Need anticoagulant first.
Generally older people over 65 have rate control. Eg BB or CCB
What does CHA2DS2VAS stand for?
Congestive heart failure Hypertension Age >75 (2) Age 65-74 (1) Diabetes Stroke or TIA (2) Vascular disease (IHD, PAD) Sex (female)
What is bifascicular block on ECG??
Combination of RBBB with left anterior or posterior hemiblock. (Left access deviation)
What is trifascicular block on ECG??
RBBB, LAD and 1st degree heart block
What’s a stokes-Adams attack?
Complete heart block (wide QRS) with dizziness and blackouts
Rx permanent pacemaker
Causes of right BBB
Infarct (inf MI)
Normal variant
Congential (vSD, fallots, ASD)
Hypertrophy (RVH. -PE,Cor pulmonale)
Causes of LBBB
Infarct inf MI
Coronary heart disease
Fibrosis
LVH - AS, HTN
What is the intial shock energy (J) in biphasic defibrillation for broad complex tachycardia?
120-150 J
What is the intial shock energy (J) in biphasic defibrillation for narrow complex tachycardia?
70-120 J
What is the intial shock energy (J) in biphasic defibrillation for atrial fibrillation?
120-150 J
What is the intial shock energy (J) in biphasic defibrillation for ventricular arrthymias?
150-200 J
Which patients With AF would you favour rhythm control over rate control?
Coexistent heart failure
First onset of AF
Obvious reversible causes
Management of paroxysmal AF?
Pill in the pocket - oral flecanide or propafenone or sotalol
And anticoagulate
Treatment options for persistent AF with heart failure?
Carvedilol and or digoxin
These improve LV function
Do not use non- dihydropyridine CCB (negatively inotropic effects)
How to differentiate between VT and SVT with BBB?
VT is more likely if:
- hx of IHD
- qrs >140
- AV dissociation
- RS >100
- capture complexs (intermittent normal QRS)
- concordance of QRS direction in v1-v6 (all positive or all negative)
- monophasic (triphasic in SVT)
- q wave in lead V6 (deep S wave in V6)
- LAD
Causes of VT?
IM QVICK
Infarction Myocarditis QT interval long Valve abnormally - mitral prolapse, AS Iatrogenic - digoxin, anti arrthymics, Cardiomyopathy (dilated) K⬇️, mg ⬇️, o2 ⬇️, acidosis
What’s the most common post MI arrthymia?
Ventricular extrasystoles (ectopics)
If frequent - consider amiodarone
Pacemarker codes?
3 letters at least
1) chamber paced (A,V, D-dual)
2) chamber sensed (A, V, D, O- none)
3) pacemarker response (triggered, inhibited, dual, reverse
4) programmable or multiprogrammable
5) p- pace, s-shocks, d- pace and shocks, o-none
Which are the most common pacemarkers used?
VVI
What’s cardiac resynchronisation therapy?
For people with heart failure
- paces biventricular +/- atrial lead
May be combined with a defibrillator
Which features with bradycardia indicate the need for treatment?
Shock - hypotension, pallor, sweating, cold, clammy.
Syncope
MI
Heart failure
Rx- atropine IV
What features indicate the need for transvenous pacing with bradycardia?
Potential for asytole
- complete heart block with broad QRS
- recent asytole
- Mobitz 2
- ventricular pause >3 seconds
If delay in transvenous: use atropine, transcutaneous pacing, adrenaline infusion
Investigation for arrthymias??
12 lead ECG
TFT
u&E (k+)
FBC
Normal?
Do holter monitoring
Holter normal?
External loop recorder
Implantable loop recorder
Management for long QT?
Avoid drugs/precipitants
Beta blockers
If QT > 500 or cardiac arrests then ICD
Post stroke and AF what is the antiplatlet/anticoagulation guidelines?
300mg aspirin for 2 weeks, then life long anti-coagulation (warfarin or DOAC)
Treatment for WPW?
Radioablatin
Meds: sotalol, amiodarone, flecanide
Top three intrinsic causes of AF
HTN, CAD, VDH
Top 3 extrinsic causes of AF
Thyrotoxicosis Acute infection (eg rheumatic heart disease) Drug and alcohol intoxication