1: Narrow Complex Tachyarrhytmias Flashcards
(106 cards)
1
Q
If the arrhythmia is atrial in origin, how will the QRS complex appear
A
Narrow complex tachycardia
2
Q
What defines a narrow complex tachycardia
A
Rate >100bpm
QRS <120ms
3
Q
Define atrial fibrillation
A
Where un-coordinated atrial activity results in irregular ventricular response
4
Q
How common is AF
A
Commonest arrhythmia
5
Q
How does the incidence of AF change
A
Increases with age
6
Q
What is paroxysmal AF
A
AF that lasts <7 days
7
Q
What is persistent AF
A
AF that lasts >7days
8
Q
What is permanent AF
A
continuous AF that cannot be cardioverted - therefore management focuses on rate control and anti-coagulation
9
Q
What are 5 common cardiac causes of AF
A
HF IHD HTN Mitral Regurgitation PE
10
Q
What are 7 non cardiac causes of AF
A
Hyperthyroidism Hypomagnesaemia Hypokalaemia Caffeine Alcohol Post-operatively Pneumonia
11
Q
What is lone AF
A
AF where no underlying cause can be identified
12
Q
What are 6 CV risk factors for AF
A
HTN IHD HF Age DM Smoking Obesity
13
Q
What are 5 intrinsic cardiac disorders increasing risk of AF
A
Mitral regurgitation Coronary artery disease Congestive HF WPW Sick sinus syndrome Cardiomyopathy
14
Q
What are 5 non-cardiac RF for AF
A
COPD Hyperthyroidism Holiday Heart syndrome Stress: sepsis or post-op Adenosine
15
Q
What is holiday heart syndrome
A
Individual develops an arrhythmia following alcohol consumption
16
Q
How do the majority of patients with AF present
A
Asymptomatic
17
Q
What are the other symptoms of AF
A
Dizziness
Syncope
Palpitations
Fatigue
18
Q
Describe the pathophysiology of AF
A
- AF is caused by automatic foci adjacent to the pulmonary veins or fibrosed tissue
- AF is sustained by re-entry circuits which is more likely if the atria are enlarged
- Un-cordinated contraction of the atria leads to turbulent blood flow and increased risk of thrombosis
19
Q
What is first line Ix for AF
A
ECG
20
Q
What will be seen on ECG in AF
A
- No p waves
- Irregularly Irregular rhythm
21
Q
What other investigations should be performed in AF to look for reversible causes
A
FBC (sepsis or anaemia) TFT (hyperthyroidism) Mg (hypomagnesaemia) U+E (hypokalaemia) Calcium
22
Q
When should a trans thoracic ECHO be performed in AF
A
If suspected valve disease causing AF
23
Q
When should a transoeseophageal ECHO be performed in AF
A
If checking for a thrombus. As thrombus most commonly occurs at left atrial appendage which is difficult to visualise on TTE
24
Q
In acute AF, if a patient is harm-dynamically compromised how should they be treated
A
- A-E approach
2. Syncronised DC cardioversion (120-150J)
25
If cardioversion is unsuccessful what should be given
Amiodarone
26
How should a stable patient with AF be managed if symptoms started <48h ago
Rhythm control is preferred.
27
How is rhythm control achieved
DC cardioversion (or IV Flecainide)
Heparin should be started in case cardioversion is delayed
28
How should a patient with AF be managed if symptoms started >48h ago
Rate control
29
How should a patient undergoing rhythm control >48h be managed
1. Anti-coagulate for 3W before elective cardioversion
OR
2. ECHO to check for mural thrombus before cardioversion
30
How is chronic AF managed
Rate or Rhythm Control
31
In which patients is rhythm control preferred
1. Young patients
2. HF patients
3. New-Onset AF
4. AF with a reversible cause
32
In which patients is rate control preferred
Majority of AF patients
33
What is first line rate control
B-blocker or non-dihydropyridine calcium channel blocker
34
What is second line rate control
digoxin
35
When should digoxin only be considered
Monotherapy for individuals with a sedentary lifestyle
36
What is 3rd line for rate control
Amiodarone
37
How is a patient rhythm controlled if symptoms <48h
Heparin (in case CV delayed)
| DC Cardioversion
38
How is a patient rhythm controlled if symptoms >48h or unsure of onset
Rate control.
| Anticoagulate for 3W then cardiovert electively
39
How is the risk of an embolic stroke in AF assessed
CHADSVASC
40
What is the CHADSVASC score
```
C ongestive HF
H TN (>140/90)
A ge >75 (2 points)
D iabetes mellitus
S troke or TIA (2 points)
V ascular abnormalities `(PAD or prior MI)
A ge 65-74
Sc sex category female
```
41
If CHADVASC >2 what does this mean
Offer anticoagulation to ALL individuals
42
If CHADVASC >1 what dose this mean
Consider anti-coagulation for males
43
If individual has AF secondary to valve disease what does this mean
You do not need to calculate the CHAD VASc score - they should automatically receive anticoagulation
44
What is used to anti-coagulate in AF
DOAC or warfarin
45
What should risk of anticoagulation be compared against
Risk of bleeding
46
What score is used to predict the risk of bleeding
HAS BLED
47
What does HAS BLED stand for
```
H TN Uncontrolled (Systolic >160)
A bnormal liver, renal function or alcohol consumption harmful
S troke
B leeding
L abile INR
E lderly >65
D rugs (NSAIDs, antiplatelets)
```
48
What score in HAS BLED indicates a high risk of bleeding
>1
49
What are 3 complications of AF
Stroke
Left-sided HF
VT
50
Where is the most common site of thrombus formation
left atrial appendage
51
What is atrial flutter
formation of a re-entry circuit within the right atrium
52
What is ventricular rate in atrial flutter determined by
AV conduction ratio
53
What is the commonest conduction ratio in atrial flutter and what rate is this
2:1 block (2 P waves for one QRS) = 150bpm
54
What are the types of re-entry circuit in atrial flutter
clockwise
| anti-clockwise
55
What is the most common re-entry circuit in atrial flutter
anti-clockwise (90%)
56
In what gender is atrial flutter more common
males (5:1)
57
How does the incidence of atrial flutter vary
increases with age
58
How do the majority of patients with atrial flutter present clinically
asymptomatic
59
How can patients with atrial flutter present
dyspneoa
syncope
palpitations
60
How can atrial flutter be differentiated from atrial fibrillation by pulse alone
in atrial flutter the pulse is regular
61
What is first line Ix for atrial flutter
ECG
62
What are 3 ECG findings of atrial flutter
- sawtooth baseline (particularly leads II, III, aVF)
- regular
- narrow complex tachycardia
63
What does a a:b block stand for
number of p waves to QRS
64
What rate is a 2:1 block
150bpm
65
What rate is a 3:1 block
100bpm
66
What rate is a 4:1 block
75bpm
67
When will patients with atrial flutter undergo an ECHO
if suspected underlying valve disease
68
Why may a trans-oesophageal ECHO be performed in atrial flutter
if suspect a thrombus (as TTE are poor for viewing the left atrial appendage - most common site)
69
How is atrial flutter managed
Similar to AF
70
Describe management in atrial flutter
Flutter is less sensitive to rate control and more sensitive to rhythm control
71
What is curative management of atrial flutter
radio frequency ablation of the tricuspid isthmus
72
What are 2 complications of atrial flutter
Atrial fibrillation
| 1:1 block - can quickly lead to VT
73
What is atrio-ventricular re-entry tachycardia
There is an accessory pathway between the atria and the ventricles
74
How will AVRT present clinically
palpitations
dyspnoea
dizziness
syncope (rare)
75
Explain the pathophysiology of AVRT
there is an accessory pathway that runs between the atria and the ventricles. This bypasses the AV node (that usually delays electrical transmission) and can lead to pre-mature ventricular activation
76
What is first Ix for AVRT
ECG
77
How will AVRT present on ECG
```
narrow complex (<120ms) tachycardia
p waves may be embedded in QRS
```
78
What is first-line management for AVRT
valsava manoueveres
79
What is second line management of AVRT
IV adenosine 6mg
80
In which individuals is adenosine contraindicated
Asthmatics
81
What is used as an alternative to adenosine in asthmatics
Verapamil
82
What is used to treat AVRT in a haemodynamically unstable individual
DC Cardioversion
83
What is the only curative treatment for AVRT
Radiofrequency ablation of the accessory pathway
84
What is Wolff Parkinson white
Presence of a congenital accessory pathway that connects the atria to the ventricles and causes ventricular pre-excitation
85
What is Wolff Parkinson White syndrome
When the accessory pathway leads to ventricular pre-excitation. As the pathway does not slow conduction it can degenerate into AF.
86
What is the most common type of AVRT
WPW
87
How does Wolff Parkinson White present
Asymptomatic
88
How does Wolff Parkinson White Syndrome present
Palpitations
Dizziness
Syncope
89
What is the accessory pathway called in WPW
Bundle Of Kent
90
Explain the pathophysiology of WPW
In WPW there is an accessory pathway (bundle of Kent) from the atria to the ventricles which does not delay impulses. This leads to pre-excitation of the ventricles
91
Explain the pathophysiology of WPW syndrome
If the individual is in AF that accessory pathway cannot delay impulses as it has no AV node. This means all signals from the atria are transmitted to the ventricles causing a rapid ventricular response and cariogenic shock as the heart does not have time to gill. It forms a re-entry circuit leading to rapid ventricular rate
92
What are 3 features of WPW on ECG
1. Shortened PR interval
2. Broad QRS
3. Delta wave = slurred upstroke of QRS
93
If individuals have type A WPW (left sided pathway) how will it present
right bundle branch block
| dominant R wave in V1
94
If individuals have type B WPW (right sided pathway, how will it present)
left bundle branch block
| no dominant R wave in V1
95
What is the definitive management for WPW
radio frequency ablation of the accessory pathway
96
What is AVNRT
generation of re-entry circuit close to the AV node
97
How will AVNRT present clinically
Dizziness
Palpitations
Dyspneoa
Syncope
98
Explain the pathophysiology of AVNRT
- electrical pathway is close to AV node
- There are 2 pathways in the AV node. Alpha = slow conduction, fast refractory
Beta = fast conduction, slow refractory
- Signal passess from AV node down the A and B pathway. As B pathway is quicker is passes down here and up the A pathway where it meets to signal + slows.
- both A and B are in refractory. As A comes out of refractory first. Signal passes down A (from SA node) and to B (which then comes out of refractory) which then passes again to A = forming a re-entry loop
99
What is first-line Ix for AVNRT
ECG
100
How will AVNRT present on ECG
1. No P waves
| 2. Narrow complex tachycardia
101
How is a haemodynamically unstable individual with AVNRT be managed
DC cardioversion
102
How is a haemodynamically stable individual with AVNRT managed
Valsava manœuvres
103
What is second-line management for AVNRT
IV adenosine (6mg)
104
In which individuals is adenosine contraindicated
Asthmatics - verapamil should be used as an alternative
105
How are episodes prevented in AVNRT
B blocker
106
What is the definitive management of AVNRT
Radio-frequency ablation of the accessory pathway
