Cardiology - Arrythmias: Tachycardias

Question 1

Inappropriate sinus tachycardia

• when does it occur
• how does it present

Answer 1

Presents in WOMEN in 3rd and 4th decades

With fatigue, chest pain, headaches, syncope and dizziness

Question 2

Inappropriate sinus tachycardia

- treatments

Answer 2

• Symptoms: beta blockers and CCBs
• Others: clonidine and SSRIs
• Ivabradine has some use

Question 3

Postural orthostatic tachycardia syndrome (POTS)

• what is it?
• When does it occur

Answer 3

= symptomatic sinus tachycardia with hypotension

Occurs post viral autonomic dysfunction
Resolves by 3-12 months

Question 4

Postural orthostatic tachycardia syndrome

- Treatments?

Answer 4

Salt tabs
Fludrocortisone
Compression stockings
Alpha agonist MIDODRINE

Question 5

Focal Atrial Tachcardia

- ? how to treat

Answer 5

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

Question 6

Atrial Flutter

- is ? percent of all SVTs

Answer 6

10% of all SVTs

Question 7

Atrial Flutter

- Associated comorbidities?

Answer 7

60% of flutter have CAD or hypertensive disease

Question 8

PITX2 gene

• ? where is it
• ? associated with what

Answer 8

PITX2 gene (paired like homeodomain 2)
on Chromosome 4q25

Associated with atrial flutter

Question 9

Atrial flutter

What heart rate and what does the ECG look like?

Answer 9

HR >250bpm

ECG: Sawtooth (esp in inferior leads and V1)

Question 10

Atrial Flutter Treatment

Answer 10

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

Question 11

What is the problem with flecainide in treating Atrial Flutter?

Answer 11

It can organise the pathways to cause an A flutter with 1:1 conduction
ALWAYS use with a BETA BLOCKER

Question 12

What is the problem with antiarrythmics used in treatment of Atrial Flutter

Answer 12

Sotolol, ibulitide, dofetilide and flecainide

Need to commence them as an inpatient due to risk of pause dependent torsade in first 48 hours

Question 13

In Atrial Flutter treatment WHERE is ablation targeted?

Answer 13

Cavotricuspid isthmus

abolishes arrythmia in 90%

Question 14

How many atrial flutter presentations develop AF in the next 5 years?

Answer 14

50%

Question 15

Aside from developing AF, what are the complications of atrial flutter?

Answer 15

LA thrombus (<20%)
Thromboembolism (14% at 5 years)
Stroke risk 4.1% per year

Question 16

Multifocal Atrial Tachycardia

• what is it?
• who gets it?
• what is it associated with?

Answer 16

= 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

Question 17

Multifocal Atrial Tachycardia

- treatment

Answer 17

• 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

Question 18

AV Nodal Re-Entry Tachycardia

• what proportion of SVTs?
• Which gender and age get it?

Answer 18

Most common SVT

Females more common in 2nd to 4th decades

Question 19

What JVP sign do you get in AV nodal re-entrant tachycardia and why?

Answer 19

Cannon a waves due to simultaneous atrial and ventricular contractions

Question 20

AV nodal re-entrant tachycardia

What rate is it usually?

Answer 20

Rate 150 - 200bpm

Question 21

AV nodal re entrant tachycardia

How does it form?

Answer 21

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)

Question 22

AV nodal re entrant tachycardia

- treatments??

Answer 22

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

Question 23

Accessory Pathway Atrial Tachycardia

- what 5 disease associations?

Answer 23

• Ebstein anomoly
• HOCM
• PAKAG2 mutation
• Danon’s disease
• Fabry’s disease

Question 24

Accessory Pathway Atrial Tachycardia

- what fails to cause this?

Answer 24

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

Question 25

What indicates a pre-excited ventricle?

Answer 25

Short PR Slurred initial QRS (Delta) Prolonged QRS

Question 26

What IS WPW?

Answer 26

A pre-excited QRS during sinus rhythm with episodes of SVT

Question 27

ECG Features of WPW:

Answer 27

- Short PR - Wide QRS with delta wave - LAD if R sided accessory pathway - RAD if L sided accessory pathway

Question 28

Conditions associated with WPW

Answer 28

``` HOCM MVP Ebstein's Thyrotoxicosis Secundum ASD ```

Question 29

AV Re-Entrant Tachycardia | ? what is it?

Answer 29

NOT a pre-excitation syndrome | The impulse goes down the NORMAL conduction system then goes back UP via the ACCESSORY pathway

Question 30

Orthodromic ('normal') AV re-entrant tachycardia ? heart rate and ECG findings ? treatment

Answer 30

Rate 200 - 300bpm ECG: QRS alternans and TWI Treat with vagal manouvres Adenosine or CCB

Question 31

Antidromic AV re-entrant tachycardia

Answer 31

Most common PRE-EXCITATION SVT Conduction goes down the ACCESSORY path and then back UP via conduction path

Question 32

Antidromic AV Re-entrant Tachycardia - ? ECG findings - ? treatment to AVOID

Answer 32

Wide QRS complexes DONT given AV blockade as it will provoke VT (beta blocker, adenosine, verapamil or diltazem)

Question 33

Best antiarrythmic to use with WPW?

Answer 33

Flecainide

Question 34

Ebstein anomoly?

Answer 34

Right heart enlargement with TR

Question 35

What to avoid in WPW?

Answer 35

Beta blockers Adenosine Verapamil Diltiazem

Question 36

Lown-Ganong-Levine's Syndrome (LGL)

Answer 36

Get paroxysms of tachycardia, type of pre-excitation syndrome

Question 37

Management of a Pre-Excitation Syndrome?

Answer 37

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