Palpitations and Dysrhythmias Flashcards
1
Q
Explain pathophysiology of Atrial fibrilation?
A
- Disorganised electric activity in the atria
- Signals are not systematically triggered via the SA node,
- Instead, are generated from all over the atria, resulting in a quivering or fibrillating (don’t contract properly) and uncoordinated atrial activity.
2
Q
What are some common causes of AF in the patient in the ED?
A
Reversible/secondary causes of AF (PIRATES)
- Pulmonary embolism
- Ischemia (IHD/MI/heart failure)
- Respiratory disease (including trauma)
- Atrial enlargement/myxoma
- Thyroid (hyper)
- Ethanol (holiday heart
- Sepsis/sleep apnoea
*can also get ectopic beats
3
Q
What is paroxysmal AF? Is it concerning?
A
-Paroxysmal AF is when there is fibrillation but it is transient
-This is more concerning because clots form and then can be thrown off when heart beats normally again
(leading to PEs/strokes)
4
Q
Explain these types of AF
Acute AF Recurrent AF Paroxysmal/intermittent AF Persistent AF Permanent AF
A
- Acute AF -onset within last 48hrs
- Recurrent AF- 2+ episodes
- Paroxysmal/intermittent AF- resolves spont in 7 d
- Persistant >7 days, terminates with cardioversion
- Permanent > 7 days cannot resolve w/ cardioversion
5
Q
What other investigations should you do in a patient with probable AF? (3)
(bedside, bloods, imaging)
A
Investigations for AF
- ECG
- 24-hr ambulatory ECG monitor if asymptomatic or symptomatic episodes < 24hrs apart - Bloods
- FBC (anemia)
- TFTs (↑T4 = thyrotoxicosis)
- U+E,
- LFT (gGT-alcohol)
- HbA1c
- lipids - Imaging Echo
- Atrial enlargement (left common)
- May see mitral valve prolapse
6
Q
How do we predict risk in AF?
A
CHA2DS2VASc score - calculates the risk of stroke in AF
o Congestive HF/LVSD 1 o Hypertension 1 o Age 65+ 1point.....75+ 2points o Diabetes mellitus 1 o Stroke/ TIA/ thromboembolism Hx 2 o Vascular disease 1 o Sex category (female) 1
anti-coagulation medication if 2+ women, or 1+ men
7
Q
When should you treat with anti coagulation?
What are your options and how do they differ?
A
Anticoagulation in atrial fibrillation
- treat men with chadsvasc 1+ or women with 2+
- give normal VTE prophylaxis until assessment is made
DOAC (e.g. rivaroxaban, apixaban, dabigitran)
- do not use if egfr<30
- can’t miss a dose
Warfarin (monitor for INR 2-3)
-can reverse and can also miss dose
Aspirin alternative
8
Q
How do we assess someone’s bleeding risk once they have been put on anti-coagulant therapy?
A
HASBLED Hypertension Abnormal liver function (clotting fx) Stroke Bleeding Labile INR Elderly Drugs and alcohol (aspirin, clopidogrel, NSAIDS)
9
Q
What is the 1st line managment of AF (both acute and chronic)?
A
ALWAYS ASSESS FOR ANTICOAGULATION
- DOACS (direct thrombin: dabigatran/ factor Xa: rivaroxaban, apixaban, edoxaban )
- vitamine K antagonist (warfarin)
RATE CONTROL IS 1ST LINE (unless unstable) (aim for <110)
- 1st line: BB or rate limiting CCB (non:hydro dil/vera)
- Digoxin (only consider in sedentary patients and heart failure)-beware of vomiting ↓K+ (this will increase risk of toxicity)
- 2nd line: combine any combo of 2 above
** don’t use sotalol as BB
RHYTHM CONTROL IS SECOND LINE
10
Q
When would you do RHYTHM control in someone with AF?
A
RHYTHM control in AF
- 2nd line if rate control not worked (chronic and acute)
- if heamodynamically UNSTABLE (syncope/shock/acute HF/MI)
- New onset AF <48 hours
- AF with reversible cause (e.g. infection)
- Clinical judgment e.g. active young patients (want to avoid rate control)
11
Q
What are the options for RHYTHM control in AF?
What do you need to bare in mind with medical conversion?
A
Electrical conversion
- DC current shock
- Preferred if heamodynamically unstable (syncope/shock/acute HF/MI)
- If not anti coagulated give LMWH first but dont delay shock
Medical conversion (bolus then infusion) -If symptoms are milder or if electrical conversion not available
12
Q
What are the options for medical cardioversion for AF?
A
Medical conversion for AF (bolus then infusion)
-If symptoms are milder or if electrical conversion not available
1st line = IV Flecainide (if no structural abn)
AMIODARONE (central line) IF STRUCTURAL ABNORMALITY or IHD (300mg 10-20min, 900mg 24hr)
13
Q
What are the risks of cardioversion for AF?
How do you minimise risk?
A
Risks of cardioversion for AF
-risk of stroke when cardioverted because coordinated contraction with throw off clots formed in static blood> thrombophylaxis 3 weeks prior if elective
14
Q
Differential for AF?
What things would be seen in those differentials?
A
Wolf-Parkinson white syndrome – Δ waves, short PR, broad QRS
Atrial flutter – 150bpm, saw tooth
15
Q
Complications of AF?
A
- Stroke/TIA (INR< 2)
- Bleed (if INR>4)
- Mesenteric ischemia (abdo pain)
- Paroxysmal AF: terminates spontaneously < 7 d, usually 48 h
16
Q
What is a supra ventricular tachycardia? (SVT)
Narrow or broad?
Whats the rate?
A
Supra ventricular tachycardia
- Occurs above ventricles
- Narrow complex tachycardias (unless BBB = broad complex)
- Rate >100 and QRS complex <120ms in width (3 squares)
17
Q
What are some symptoms of SVT?
A
Symptoms of SVT
- Chest pain
- Palpitations
- Dizzyness
- Sweating
- SOB
- Feeling faint
Worrying signs: ‘2s and 2 hearts’
- Cardiogenic shock (hypotension)
- Syncope
- acute MI
- acute Heart failure
18
Q
What are 4 main types of SVT?
A
Causes of SVT
- Atrial fibrillation
- Atrial flutter
- Paroxysmal SVT
- WPW syndrome
19
Q
What is atrial flutter?
What will the pulse normally be?
A
Atrial flutter
- the atria contract at 300bmp
- this is too fast for the AV node to conduct
- the ventricles contract at a slower rate most common is 2:1 (pulse 150)
- can also be 3:1 (100) or 4:1 (75)
20
Q
Explain the ECG in atrial flutter?
- narrow vs wide
- irregular vs regular
- p waves vs no p waves (discrete or continuous)
A
ECG atrial flutter (saw soothed baseline no visible p wave)
- Narrow QRS (its an SVT)
- Regular
- P waves present and continuous
21
Q
Risk factors for atrial flutter?
A
Atrial flutter risk factors
- M>F
- ↑age
- CAD/HTN/obesity
- valve dysfunction
- alcohol
- COPD/sleep apnoea
- drugs (NSAIDs)
- thyrotoxicosis
22
Q
What is the ACUTE managment of atrial flutter (<48 hours)?
- if adverse features
- if no adverse features
A
Adverse features? (shock, syncope, MI, HF)
- if so SHOCK (up to 3 attempts) GET HELP
- then give amiodarone 300mg IV over 10-20 mins
- repeat shock
- amiodarone 900mg over 24 hours
If no adverse features (treat as regular narrow tachy)
- Vagal manoeuvres
- Adenosine 6mg → 12 mg → 12 mg (reduce tachycardia and may reveal flutter)
- If sinus rhythm not achieved, possible atrial flutter then… Rate control e.g. BB or rate limiting CCB (dil or vera)
23
Q
What is the managment of atrial flutter if they’ve had it for over 48 hours?
A
Atrial flutter lasting >48 hours
- catheter ablation is 1ST LINE
- electric cardio version (with anticoag) and chemical cardio version can also be used
24
Q
Explain the ECG in Atrial fibrillation?
- narrow vs wide
- irregular vs regular
- p waves vs no p waves (discrete or continuous)
A
Atrial fibrillation
- Narrow complex (SVT)
- irregular (irregularly irregular QRS)
- no p waves
25
Explain the ECG in AVRT/AVNRT?
- narrow vs wide
- irregular vs regular
- p waves vs no p waves (discrete or continuous)
AVRT/AVNRT
- narrow
- regular
- no clear p waves seen before QRS (may be immediatly before/after QRS or seen inverted after QRS)
26
What investigations should you do in a patient with SVT?
ECG
Bloods – investigate associated causes
-TFTs (↑T4), FBC, ESR, U+E, LFT, Coagulation screen
CXR – check for signs of heart failure or valvular defects
Echo – evaluate underlying cardiac function, structural abnormalities, evidence of CAD or pericardial fluid
27
Explain the ECG in Sinus tachycardia?
- narrow vs wide
- irregular vs regular
- p waves vs no p waves (discrete or continuous)
Sinus tachycardia
- Narrow complex
- Regular
- P waves (not continuous)
28
How should you treat tachycardias?
Via the tachycardia algorhythm
1. Adverse features? (shock, syncope, MI, HF)
- if so SHOCK (up to 3 attempts) GET HELP
- then give amiodarone 300mg IV over 10-20 mins
- repeat shock
- amiodarone 900mg over 24 hours
2. Figure out whether broad or narrow and then treat condition
29
What is AV nodal re-entry tachycardia (AVNRT)
AV nodal re-entry tachycardia (AVNRT)
- circuits form WITHIN the AVN causing narrow complex tachycardias
- very common (most common cause of regular palpitations for people with no structural heart abnormalities)
30
How do you treat AVNRT?
Treating AVNRT
Adverse features? (shock, syncope, MI, HF)
-if so SHOCK (up to 3 attempts) GET HELP
-then give amiodarone 300mg IV over 10-20 mins
-repeat shock
-amiodarone 900mg over 24 hours
If no adverse features (treat as regular narrow tachy)
1. Vagal manoeuvres (valsalva manœuvre-blow into syringe, positioning, carotid massage if not CI)
2. IV Adenosine 6mg → 12 mg → 12 mg (reduce tachycardia and may reveal flutter)
3. If sinus rhythm achieved probably re-entry paroxysmal SVT (if not think atrial flutter>BB or CCB)
31
What is atrioventricular re-entry tachycardia?
Definitive management?
-anatomical accessory pathway (Bundle of Kent)
(atria>AVN>ventricles>accessory pathway>atria)
-E.g. wolf parkinson white
Definitive management is ablation of the pathway
32
What ECG changes would you see in WPW syndrome?
WPW (form of AVRT)
- Short PR interval <3 squares (<120ms)
- narrow QRS complex (most common). Can have wide complex in antidromic
- Delta waves (upstroke) before the QRS complexes
33
What drugs should be avoided in WPW?
Be wary of rate control drugs e.g. BB, CCB , digoxin adenosine
34
Explain what VT is
Ventricular tachycardia
- Ventricular pacemaker cells to overtake rate of SAN
- Monomorphic (common)
- Polymorphic/Toursaads (more likely to be assosiated with electrolyte abnormalities or toxicities) (give 2g IV magnesium in 10 mins)
35
```
What does the ECG look like in VT?
(rate)
(narrow or broad)
(regular or irregular)
(p waves?)
```
Ventricular tachycardia
- Tachycardia >150bpm
- Broad complex QRS (>3 small squares)
- Regular
- No P waves or T waves
36
Investigations for VT?
Full A to E
Bloods
-Urgent U&E: esp. ↓K+ & Mg+, Ionised Ca2+, PO4-
-Therapeutic drug levels e.g. digoxin or TCA
-Troponin/CK/myoglobin – screen for complications
-CXR – element of congestive heart failure (might also hear fine crackles and raised JVP)
37
What is the treatment of VT WITH pulse?
(Think about that sim you did)
Adverse features? (shock, syncope, MI, HF)
- if so SHOCK (up to 3 attempts) GET HELP
- then give amiodarone 300mg IV over 10-20 mins
- repeat shock
- amiodarone 900mg over 24 hours
If no adverse features (treat as VT)
- amiodarone 300mg IV over 10-20 mins
- amiodarone 900mg over 24 hours
*if ↓Mg (due to alcohol, diuretics) give IV magnesium
38
What is the treatment of VT WITHOUT pulse?
Pulseless VT or VF-cardiac arrest algorhythm
-CRP and attach defibrillator pads
UNSYNCHRONISED DEFIBRILATION
39
Whats the definitive treatment for VT?
Ventricular tachycardia
- may be legible for radiofrequency ablation (remove ventricular tissue responsible for rate
- implantable cardioverter defibrillators (ICDs) – if sustained VT causing syncope or ejectraction fraction < 35%, prev cardiac arrest due to VT/VF, MI
40
Complications of VT?
Complications of VT
- Ventricular fibrillation or pulsless VT (cardiac arrest pathway)
- Torsades (give IV Mg)
- Congestive heart failure or cariogenic shock (increased ventricular rate>↓preload>↓blood flow to vital organs
41
What is the PR interval?
| How long should the P-R interval be?
- PR interval is from beginning of P to beginning of QRS
| - PR interval is 3-5 small sqaures (120-200)
42
what is heart block?
| What are some causes?
Heart block
-Conduction abnormality (AVN has delayed response to SAN)
Causes
- INFERIOR MI (will present as narrow QRS)
- aging/scarring/IHD
- well trained athletes
- lyme disease/SLE
- medication (flecainide, BB, CCB, digoxin, magnesium)
43
What are the types of heart block?
What is complete heart block?
1st degree- constant prolonged PR (>1 big square/200ms)
2nd degree mobitz type 1: progressive lengthening PR , then drop, then back to normal WENKEBACK
2nd degree mobitz type 2: Fixed prolonged PR with regular dropping of QRS (ratio 2:1 or 3:1)
3rd degree: complete block between SAN and AVN
-contract independently
44
How will the different types of heart block present?
1st degree-asymptomatic
2nd degree- Dizzy, syncope, fatigue, chest pain, SOB palpitations
3rd degree-same but may have confusion. STOKE ADAMS ATTACK- sudden syncope without warning, loss of consciousness
45
What is the most common cause of heart block? How does this look on ecg?
Cardiac ischaemia is most common cause of heart block
- SPECIFICALLY inferior wall MI
- Will often lead to narrow QRS complex
46
What tests should be done in someone who has heart block
```
ECG (look for previous ischemic changes)
Bloods
-FBC
-U+Es
-Mg
-Ca
-TFTs
```
Drug history and PMH of cardiac problems
47
```
What does an ECG look like in complete heart block?
(brady/tachy?
pr interval length?
p waves regular or irregular?
QRS regular or irregular?
QRS narrow or broad?
relationship of P to QRS?)
```
```
Complete heart block
(men dont deal well with brake ups)
-bradycardia usually 30-40bpm
-prolonged PR interval
-p waves regular
-QRS irregular
-QRS broadened (if proximal) or narrow (if distal/near AVN)
-no connection to QRS complex
```
48
How do you acutely manage bradycardia if adverse features?
BRADYCARDIA PATHWAY
-A to E assessment attach DEFIB and lay flat
1. If ADVERSE features (shock <90, syncope, acute HF/MI)
- 500mcg IV atropine
- repeat Atropine every 2-3 mins until maximum of 3mg
AND
-TRANSCUTANEOUS pacing (central line)
AND
- isoprenaline/adrenaline infusion titrated to response
- aminophylline or dopamine or glycopyrolate
2. if no response do TRANSVENOUS PACING (central line)
49
What is the chronic managment of heart block?
Chronic managment of heart block
| -if MOBITZ TYPE 2 or COMPLETE they need PERMANENT PACEMAKER
50
What medication can you give for heart block in BB or CBB OD
Glucagon
51
In AF when would you use a Holter monitor?
In AF when would you use an external loop recorder?
In AF when would you use an event recorder?
- Palpitations should first be investigated with a Holter monitor after initial bloods/ECG
- If normal, still with symptoms do an external loop recorder
- Event recorder ECG if symptomatic eps. > 24hrs apart
52
When giving Adenosine what should you remember?
Adenosine has short half life
- Best given with 20ml saline flush to hurry it along
- Give in ACF (as central as poss)
53
What can torsades be caused by?
Hypokalaemia and Hypomagneseamia (you give IV mag sulfate)
54
When do you use synchronised and when do you use desynchronised shock?
unsynchronised shock=pulseless
| synchronised shock= with pulse
