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Flashcards in Electrophysiology Deck (131)
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31

What is the significance of agonal nocturnal breathing in a patient with suspected cardiac arrhythmia?

Equivalent of syncope/ventricular arrhythmia. ?aborted event

32

How does fever influence Brugada?

Reduction in sodium current resulting in predisposition to ventricular arrhythmia

33

What is the diagnostic criteria for type 1 Brugada Syndrome?

1. Symptomatic
- Type 1 Brugada pattern (V1 or V2) at rest or with flecainide challenge
2. Asymptomatic
- type 1 Brugada pattern with
- first degree block, LAD
- atrial fibrillation
- late potentials, fragmented qrs, st-t wave alternans with VEB
- absence of structural heart disease
- absence of coronary artery disease

34

What is the definition of “symptomatic” in patients with Brugada?

VF/VT
Inducible VT on EP
Unexplained syncope
Nocturnal agonal respiration
Family history of SCD <45 years
Family history Type 1 Brugada pattern

35

What is the definition of Type 2 Brugada?

1. Type 2 Brugada pattern
2. Conversion to Type 1 with flecainide challenge
3. Additional feature listed below
- VF/VT
- inducible VT on EP
- family history SCD <45
- family history of Type 1 ECG
- agonal respiration
- unexplained syncope

36

What is the evaluation of suspected Brugada Syndrome?

Echo
+/-CMR
Stress testing/imaging

37

In the setting of wide complex tachycardia, what are the features suggestive of VT over SVT with aberrant conduction?

Capture beat
Fusion beat
Positive or negative concordance in QRS in chest leads
No mans land axis (pos aVR and neg aVF and lead 1)
RSR pattern with taller left rabbit ear
Absence of typical LBBB or RBBB pattern

38

How do you risk assess people with Brugada pattern without symptoms?

Family history
Cardiac imaging - echo/MRI
Drug Challenge if Type 2
Signal averaged ECG
Consider EP study in Type 1 asymptomatic patients
Genetic testing if mutation identified in family

39

What are the indications for Flecanide challenge in those with Type 2 brugada pattern?

Family history of SCD<45 years
Family history of Type 1 pattern

No family history, recommend against challenge

40

What is the sensitivity of flecainide drug challenge in patients with Type 2 Brugada for Type 1 pattern?

15-100%

41

What are the indications to stop a drug challenge for ?Brugada?

Type 1 brugada pattern
>2mm increase in ST elevation with Type 2
Ventricular premature beats
QRS widening >30%

42

What is the rate of sustained ventricular arrhythmia following drug challenge?

1-2%

43

What is the duration of ECG monitoring post Flecainide challenge for Brugada?

30min if IV
4 hours if oral
ECG at 90 min is useful

44

VT on exertion makes you suspicious of what diseases?

HOCM
CPVT

45

What proportion of patients with Brugada pattern ECG with inducible VT on EP studies will develop and arrhythmic event?

3.3%

46

What is the management of Brugada Syndrome?

1. Treat pyrexia
2. ICD implantation
3. Antiarrrhythmics indicated if refusing ICD or multiple shocks (quinidine or amiodarone)
4. Avoid sodium channel blockers (apart from quinidine)
5. Catheter ablation - if recurrent events
6. Family Testing

47

What is the family testing in a patient with Brugada Syndrome?

ECG and clinical history
If negative for repeat assessment every 1-2 years as may still develop disease

48

What are the rates of complications with ICD placement over 6 years?

37% inappropriate shock
30% lead issues

49

What is the incidence of AF >30s in patients in sinus with mitral stenosis on holter?

What is the rate of TIA/stroke?

29%
5.7%

50

What are the ecg features of RVOT VT?

LBBB morphology
Rightward axis (positive inferior leads)

51

Physiology of typical slow fast AVNRT

Atrial premature beat allows slow pathway conduction while fast is refractory.

Slow pathway then is able to conduct through to the fast pathway resulting in AVNRT

52

Which has the shorter refractory period, slow or fast pathway of AVN?

Slow pathway - short refractory period
Fast pathway - long refractory period

53

What are the potential triggers for AVNRT?

nicotine, alcohol, stimulants, exercise

54

ECG features of Typical AVNRT

P waves close to QRS (commonly after)
Retrograde P waves

55

ECG features of Atypical AVNRT

Very late retrograde p waves often shortly before the next QRS

56

What is the modified valsalva?

Exhaling against a closed glottis for 15 seconds
Followed by supine re-positioning with passive leg raise for 15 seconds

57

What is the adenosine dose for a patient with SVT with orthotopic heart transplant

1mg

58

What is the acute arrhythmic management of AVNRT?

1. Modified valsalva twice
2. Adenosine if no contraindication
3. IV beta blockers of calcium channel blocker

59

Long term management of recurrent AVNRT

1. Patient education on modified valsalva and pill in pocket

2. Chronic suppressive therapy with anti arrhythmics

3. Catheter ablation 95% success

60

What are the differentials for SVT with retrograde p waves with short RP interval

Typical AVNRT
AVRT with accessory pathway