Electrophysiology Flashcards Preview

RACP Cardio AT > Electrophysiology > Flashcards

Flashcards in Electrophysiology Deck (131)
Loading flashcards...
61

What is the definition of short RP interval?

62

What causes SVT with abnormal p waves with short RP interval

Atrial tachycardia with AV nodal conduction delay

63

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

Atypical AVNRT
AVRT with slow accessory pathway

64

What are retrograde p waves on ECG?

Inverted p waves in inferior leads

65

What are the differentials for SVT with abnormal p waves with a long RP interval

Atrial tachycardia
Uncommonly from atypical AVNRT

66

What are the important ECG features to assess in SVT?

Atrial Rate
P wave morphology
RP relationship
AV relationship

67

What is the most common side for antidromic AVRT?

Left sided as needs 4cm between AV node and bypass tract

68

What is the acute arrhythmic management of orthodromic AVRT?

1. Modified Vagal
2. Adenosine
3. Verapamil
4. Beta Blocker/Procainamide

69

What is the acute arrhythmic management of antidromic AVRT?

Procainamide
If known to be AVRT then adenosine, verapamil, IV beta blockers

70

What is the medical treatment for recurrent AVRT?

1. Flecainide
2. Proprafenone

71

What are the contraindications to flecainide?

Heart block
Heart failure
Structural heart disease
Ischaemic heart disease

72

What are the contraindications to propafenone?

Bradycardia
Brugada syndrome
Heart failure
Chronic airways disease

73

What are the contraindications to procainamide?

Heart block
SLE
Torsades

74

What is the rate of stroke when cardioverting AF of >48 hours without preceding anti-coagulation?

5-7%

75

What are the ECG features which increase the likelihood of VT?

Capture beat, fusion beat
AV dissociation
Positive of negative concordance in chest leads
Absence of typical RBBB/LBBB
Extreme axis
Complexes >160

76

What is brugada sign? What does it indicate

Distance from start of QRS to nadir of S wave is 100ms
More likely VT

77

What is Josephson sign?

Notching near nadir of s wave, likely VT

78

What does an RSR with a taller left rabbit ear indicate?

Specific for VT

79

What is the use of the Vereckei Algorithm?

Used to diagnose VT over SVT with aberancy

80

Describe the steps of the Vereckei Algorithm?

1. AV Dissociation
2. Initial R wave in AVR
3. Atypical BBB pattern
4. Vi/Vt <1

Yes to any of these is VT

81

Describe the steps of the Brugada Algorithm?

1. Absence of RS complex in all precordial leads
2. R to S intercal >100ms in one precordial lead
3. AV dissociation
4. Morphology criteria for VT present in V1 and V6

82

What are the morphological criteria for RBBB morphology VT in the chest leads?

V1
Smooth monophasic R wave
Notched downslope of R wave (taller left rabbit ear)
qR complex in V1

V6
negative QS complex
R/S ratio <1 (small R big S)

83

What are the morphological criteria for LBBB morphology VT in the chest leads?

V1
R wave >30-40ms
Notching of S wave
RS interval >60-70ms

V6
QS wave (highly specific)
qR pattern (small q large R)

84

What is ohms law formula?

Voltage = current * resistance

85

What is the resistance aimed for at pacemaker lead tips?

400-1200

86

What is the purpose for high resistance in pacemaker leads?

Preserve battery life

87

What is the typical amplitude ranges for signals recorded from atrial and ventricular leads?

1.5-5 and 5-25mV

88

What occurs if the atria and ventricular signals have amplitudes lower than the respective amplitude ranges?

Undersensing and potential inappropriate delivery of pacing pulses

89

Yield of holter monitor in syncope?

2%
Useful to fund cardiologists’ Ferrari’s

90

Yield of telemetry monitoring in syncope?

<1%