Arrhythmias - booklet Flashcards
1
Q
Basic steps for interpreting ECG
A
- Rate
- Rhythm - regular, sinus arrhythmia, irregular
- Axis - AVL most positive = left axis deviation, lead 3 most positive = right axis deviation
- Intervals - PR, QRS, QT
- ST/T wave changes
2
Q
What to look for in intervals?
A
- PR - 120-200ms, if short look for delta wave of WPW
- QRS up to 120ms - if tall consider LVH
- QT - 400-440ms or 2 large squares
3
Q
Classification of bradycardia
A
- Absolute - less than 40bpm
- Relative - HR is inappropriately slow for haemodynamic state of pt
4
Q
Sign of unstable bradycardia
A
- Systolic BP less than 90
- HR less than 40
- Poor perfusion
- Poor urine output
- Ventrical arrhythmias requiring suppression
- HF
5
Q
What is sick sinus syndrome?
A
Sinus node dysfunction (aka tachy-brady)
Causing sinus bradycardia
Need pacemaker if persistent
6
Q
Causes of sinus bradycardia
A
- sick sinus syndrome
- Medications
- Hypothyroidism
- Hypothermia
- Sleep apnoea
- Rheumatic fever
- Viral myocarditis
- Amyloidosis
- Haemochromatosis
- Pericarditis
7
Q
AV node block types
A
- First degree - prolonged PR interval more than 200ms
- Second degree Mobitz Type 1 Wenckebach - progressively longer PR interval with dropped QRS
- Second degree Mobitz type 2 - prolonged PR interval (fixed) with sudden drop of QRS
- Third degree Complete heart block - disassociation between ventricles and atria
8
Q
Management of AV heart block
A
- First degree - monitor for further block, nothing
- Second 1 - nothing, monitor for more severe eg if syncope/dizzy
- Second 2 - Permanent pacing arranged in absence of recent coronary event and if drugs exlcuded
- Third - Urgent pacing within 24hrs except those recent coronary event when likely to normalise
9
Q
Mobitz type 1 vs 2
A
- 1 - can be present in young fit patients with high vagal tone, can be seen during night, rarely progresses to complete block
- 2 - indicates more serious involvement of conduction system, pacing should be arranged if no recent coronary event
10
Q
Causes of complete heart block
A
- Digoxin toxicity
- Inferior STEMI - resolves within hours-days
- Severe hyperkalaemia
11
Q
Medical management of complete heart block
A
- Atropine if haemodynamically unstable
- Isoprenaline
12
Q
Most common tachycardia in clinical practive
A
Atrial fibrillation
13
Q
Natural course of AF
A
- Initial brief paroxysmal attacks
- Increasing duration of atatcks
- Persistent and permanent AF - often have no or atypical symptoms
14
Q
Complications of AF
A
- Haemodynamic instability
- ACS
- CCF
- Cardioembolic stroke
15
Q
Diagnosis and assessement of AF
A
- Manual pulse checks for irregularity
- Assess for breathlessness, palpitations, syncope, dizziness, chest discomfort, previous TIA/stroke.
- ECG
Esp common in obese pts with OSA
16
Q
If AF paroxysmal, what is recommended?
A
- Further cardiac monitoring
- 24hr ECG
- AliveCor app/cardiac monitor - repeated snapshots over time
17
Q
When to refer paroxysmal attacks to cardiology?
A
- If suspicion remains high in a patient you would anticoagulate
- Unexplained syncope
Need more prolonged monitoring –> cardiology can have Holter monitor or implantable loop recorder
18
Q
When to perform echo in AF?
A
- Suspect structural heart disease (symptoms or murmur or signs of HF)
- Rhythm control strategy (cardioversion) is considered
- Baseline echo needed for long term management
19
Q
Management aims for AF
A
- Anticoagulate to prevent stroke
- Rate control
- Rhythm control
20
Q
How to quantify risk in AF of stroke?
A
CHADSVASC score
21
Q
When to anticoag based on CHADSVASC?
A
- Score 2 or more - significant risk - offer anticoag
- Score 1 - intermediate - in men consider, keep bleed risk in mind
- Score 0 - low risk, no anticoag offered
- Score of 1 or 0 in women low risk, not advised
22
Q
How to reduce risk of bleeding if going on anticoag (from CHADVASC score advice)?
A
- Control hypertension
- Have good INR control
- Minimise aspirin/NSAIDs use
- Do not exceed recommended alcohol intake/week
23
Q
What does HAS-BLED score estimate?
A
Rate of major bleeds per 100 patient years
24
Q
Anticoag options AF
A
- DOACs usually
25
Criteria for rhythm control management
* Reversible cause of AF
* New onset of AF
* Heart failure caused by AF
* Symptoms despite rate control
26
Criteria for rate control
* Non-reversible cause
* Not new onset of AF
* No HF caused by AF
* No symptoms when rate controlled adequately
27
Options for rate control
* Beta blocker
* CCB
* Digoxin
28
Rhythm control options
* Cardioversion - immediate or delayed
* Long term control using medications
29
When is immediate cardioversion used?
* Presenting with AF for less than 48hrs
* Causing life threatening haemdynamic instability
30
Options for immediate cardioversion
* Pharmacological - flecainide, amiodarone (if structural heart disease use ami)
* Electrical - using defibrillator
31
Long term rhythm control AF
Beta blockers
Dronedarone - 2nd line if had successful cardioversion
Amiodarone - HF/LVSD
32
Management for paroxysmal AF
Pill in pocket - use when attack occurs, usually flecainide
33
What is offered if rate, rhythm control not worked?
Ablation - left atrial or AV node with PPM
34
SVT cause usually
AVNRT or AVRT
Depend on AV node conduction and therefore can be terminated by blocking AV node
35
SVT initial management
* Vagal manouvres if stable
* eg Breath holding
* Valsalva - bear down as if pooing or blow hard into syringe to move plunger
* Carotid massage
36
Management SVT not terminated by vagal maneuvures
* IV adenosine or CCBs
* Adenosine given as rapid IV bolus
* If tachy continues despite this rhythm is probably atrial flutter or tachycardia
* AVRT is excluded and AVNRT is very unlikely
37
Management for hypotensive, pulmonary oedema, chest pain with ischaemia or unstable pts with SVT
* Synchronised cardioversion following sedation at 150J
38
Other medical management for SVT
* Verapamil - but contraindicated in those on beta blockers or LV dysfunction
* IV flecainide - best but avoid in patients with MI
39
VT - when?
* Broad complex tachycardia following STEMI is nearly always VT
40
Management VT
* Haemodynamically unstable - cardioversion with 150-200J shock
* Suppression can be achieved with beta blockers but careful if hypotensive or LV is significantly impaired
* Amiodarone can be tried
* Lidocaine can be tried
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