Cardiology - Arrythmias: Tachycardias Flashcards
Inappropriate sinus tachycardia
- when does it occur
- how does it present
Presents in WOMEN in 3rd and 4th decades
With fatigue, chest pain, headaches, syncope and dizziness
Inappropriate sinus tachycardia
- treatments
- Symptoms: beta blockers and CCBs
- Others: clonidine and SSRIs
- Ivabradine has some use
Postural orthostatic tachycardia syndrome (POTS)
- what is it?
- When does it occur
= symptomatic sinus tachycardia with hypotension
Occurs post viral autonomic dysfunction
Resolves by 3-12 months
Postural orthostatic tachycardia syndrome
- Treatments?
Salt tabs
Fludrocortisone
Compression stockings
Alpha agonist MIDODRINE
Focal Atrial Tachcardia
- ? how to treat
Carotid massage / valsalva / adenosine to see the p wave
Then treat as per SVT
Catheter ablation is an option, effective in >80% if recurrent focal AT and no response to medical treatments
Atrial Flutter
- is ? percent of all SVTs
10% of all SVTs
Atrial Flutter
- Associated comorbidities?
60% of flutter have CAD or hypertensive disease
PITX2 gene
- ? where is it
- ? associated with what
PITX2 gene (paired like homeodomain 2) on Chromosome 4q25
Associated with atrial flutter
Atrial flutter
What heart rate and what does the ECG look like?
HR >250bpm
ECG: Sawtooth (esp in inferior leads and V1)
Atrial Flutter Treatment
1) Adenosine (can unmask the diagnosis AND 15% will terminate)
2) if HD unstable then cardioversion (NEED anticoagulation prior)
3) Antiarrythmics for recurrent episodes:
sotolol, ibutiline, dofetilide and flecainide
4) Ablation
What is the problem with flecainide in treating Atrial Flutter?
It can organise the pathways to cause an A flutter with 1:1 conduction
ALWAYS use with a BETA BLOCKER
What is the problem with antiarrythmics used in treatment of Atrial Flutter
Sotolol, ibulitide, dofetilide and flecainide
Need to commence them as an inpatient due to risk of pause dependent torsade in first 48 hours
In Atrial Flutter treatment WHERE is ablation targeted?
Cavotricuspid isthmus
abolishes arrythmia in 90%
How many atrial flutter presentations develop AF in the next 5 years?
50%
Aside from developing AF, what are the complications of atrial flutter?
LA thrombus (<20%)
Thromboembolism (14% at 5 years)
Stroke risk 4.1% per year
Multifocal Atrial Tachycardia
- what is it?
- who gets it?
- what is it associated with?
= at least 3 different distinct P wave morphologies due to triggered automaticity from multiple foci
Seen mainly in older males
Associated with:
- Chronic pulmonary disease
- Acute illness
Multifocal Atrial Tachycardia
- treatment
- Treat precipitating cause
- Keep O2 >90%
- CCBs verapamil or diltiazem
- Beta blockers MAY work BUT if they have lung disease they might not tolerate them
AV Nodal Re-Entry Tachycardia
- what proportion of SVTs?
- Which gender and age get it?
Most common SVT
Females more common in 2nd to 4th decades
What JVP sign do you get in AV nodal re-entrant tachycardia and why?
Cannon a waves due to simultaneous atrial and ventricular contractions
AV nodal re-entrant tachycardia
What rate is it usually?
Rate 150 - 200bpm
AV nodal re entrant tachycardia
How does it form?
In 10% it is induced by a PVC
Two ways it develops.
TYPICAL: conduction down slow pathway then back up by fast (so short PR)
ATYPICAL: conduction down fast pathway then back up by slow (so long RP)
AV nodal re entrant tachycardia
- treatments??
Physical:
- Physical vagal manouvres
Pharmaco: - Adenosine - AV node blockade/slowing: EITHER Beta blocker Verapamil or diltiazem Flecainide
Catheter Ablation:
Curative in >95% but 1% need a PPM
DCT if HD compromise
Accessory Pathway Atrial Tachycardia
- what 5 disease associations?
- Ebstein anomoly
- HOCM
- PAKAG2 mutation
- Danon’s disease
- Fabry’s disease
Accessory Pathway Atrial Tachycardia
- what fails to cause this?
Failure of electrical partitioning between atrium and ventricle
As a result you get conduction from atrium to ventricle faster than going via the normal pathway
SO that ventricle is “pre-excited”
THEREFORE if you have a ‘Right Sided Pathway’ it means RV is pre-excited and there is LBBB
if you have a ‘left sided pathway’ it means the LV is pre-excited and there is RBBB
What indicates a pre-excited ventricle?
Short PR
Slurred initial QRS (Delta)
Prolonged QRS
What IS WPW?
A pre-excited QRS during sinus rhythm with episodes of SVT
ECG Features of WPW:
- Short PR
- Wide QRS with delta wave
- LAD if R sided accessory pathway
- RAD if L sided accessory pathway
Conditions associated with WPW
HOCM MVP Ebstein's Thyrotoxicosis Secundum ASD
AV Re-Entrant Tachycardia
? what is it?
NOT a pre-excitation syndrome
The impulse goes down the NORMAL conduction system then goes back UP via the ACCESSORY pathway
Orthodromic (‘normal’) AV re-entrant tachycardia
? heart rate and ECG findings
? treatment
Rate 200 - 300bpm
ECG: QRS alternans and TWI
Treat with vagal manouvres
Adenosine or CCB
Antidromic AV re-entrant tachycardia
Most common PRE-EXCITATION SVT
Conduction goes down the ACCESSORY path and then back UP via conduction path
Antidromic AV Re-entrant Tachycardia
- ? ECG findings
- ? treatment to AVOID
Wide QRS complexes
DONT given AV blockade as it will provoke VT (beta blocker, adenosine, verapamil or diltazem)
Best antiarrythmic to use with WPW?
Flecainide
Ebstein anomoly?
Right heart enlargement with TR
What to avoid in WPW?
Beta blockers
Adenosine
Verapamil
Diltiazem
Lown-Ganong-Levine’s Syndrome (LGL)
Get paroxysms of tachycardia, type of pre-excitation syndrome
Management of a Pre-Excitation Syndrome?
Do exercise stress test
IF LOSS of pre-excitation (happens in 20%) then it is a PREDICTOR OF LOW RISK
Then do EP if persistent pre-excitation.
If you can induce an arrythmia then ABLATE
