Atrial Fibrillation & Flutter

Question 1

Is A.Fib a type of SVT or is it grouped with Atrial flutter?

Answer 1

Both A.Fib and flutter are types of SVT as they both originate over the purkinje-His bundle

Just for information:
Atrial dilatation for example due to Mitral stenosis or congestive HF as well as cardiac ischaemia (MI CAD) are causes of atrial fibrillation. Atrial dilatation affects its electric circuitry => causing Atrial remodeling => re-entry circuits

Question 2

The management plan for A.fib is typically composed of 3 components: Rate control, rhythm control, and anticoagulation. In what scenario is one of the 3 components not pursued?

Answer 2

When there is permanent A.fib (prolonged >1 year + decision made to no longer pursue rhythm control), Rhythm control is stopped

Question 3

What are the 4 types of A.fib?

Answer 3

Paroxysmal A.fib <7 days
Persistent A.fib >7 days
Long standing persistent >1 year
Permanent A.fib >1year + decision made to no longer pursue rhythm control

Question 4

What % of those with paroxysmal A.fib will develop Persistent A.fib?

Answer 4

25%

Question 5

Define Atrial fibrillation

Answer 5

Irregularly irregular arrhythmia characterised by rapid and irregular depolarisation of the cardiac atria
To bypass the last part, you can state the ECG findings of A.fib

Question 6

List all the causes of atrial fibrillation

Answer 6

CCCHASE = 2 cardiac CHASE noncardiac

Cardiac causes: CC
C1: LA enlargement due to mitral stenosis or congestive HF
C2: Ischaemia => Previous MI/CAD

Non-cardiac causes:
Catecholamines: Epinephrine/NE released during sepsis, post-op, phaeochromocytoma, thyrotoxicosis/hyperthyroidism

Hypoxia: PE, pneumonia, COPD

Alcohol binge (Holiday heart syndrome) => Hypokalaemia + Hypomagnesia

Sympathomimetics: Cocaine, MDMA

Electrolytes: Hypokalameia/hyperkalaemia, Hypomagnesia

Question 7

How would the cardiac causes of Atrial fibrillation lead to an arrhythmia?
honours => not in book

Answer 7

Atrial dilatation for example due to Mitral stenosis or congestive HF as well as cardiac ischaemia (MI CAD) are causes of atrial fibrillation. Atrial dilatation affects its electric circuitry => causing Atrial remodeling => re-entry circuits

Question 8

What are the typical symptoms you would like to elicit in a hx of A.fib.
There is also extra information about what to ask in a hx if you wanna have a go at it too

Answer 8

Any arrhythmia:
Palpitations
Syncope/pre-syncope
SOB/Dyspnoea
Chest pain
Fatigue
! feeling of rapid neck pulsation !
+ Sxs of HF (+orthopnoea, PND, weight gain, swelling,)
+ Sx of Thromboembolic (neurological deficit for stroke, Abdo pain for mesenteric ischaemia, Leg pain for critical limb ischaemia and DVT, chest pain for PE)

Extra
+ RF of CAD (previous MI, surgery,
+ Thyroid, alcohol use…. Must ask about all RF

Question 9

You are asked to perform an cardiac examination on a patient with atrial fibrillation. What findings are you looking for?

Answer 9

Dont forget heart failure (kinda all the findings lol)
Vitals: maybe tachypneic
General inspection: Typically asymptomatic, maybe SOB
Closer Inspection: Peripheral cyanosis, peripheral oedema, raised JVP
Palpation: Peripheral/sacral oedema, parasternal heave
Percussion: Pulmonary oedema is hyporesonant
Auscultation: Mitral stenosis (cause), tricuspid regurg for HF

Question 10

List the RFs of Atrial fibrillation

Answer 10

From the causes:
Modifiable:
Smoking
Alcohol
HTN
Glycaemic control (or diabetes)
Hyperthyroidism

Non-modifiable:
Male
Age
Hx of CAD/MI
Family hx
Diabetes (or glycemic control)
!Rheumatic heart disease

Question 11

What leads are best for assessing the P waves?

Answer 11

V1 + inferior leads (II, III, aVF)

Question 12

What ECG findings are consistent with A.fib

Answer 12

Irregularly irregular
Tachycardia
No P waves (instead, fibrillating waves in leads V1, II, III, aVF
Narrow QRS <80ms or 0.08s

Question 13

What investigations will you perform for A.fib? always with justification

Answer 13

As for any arrhythmia: except ECG
Bedside:
ECG/!Holter monitor: Looking for tachycardic, irregularly, irregular, absent P waves/fibrillating waves narrow QRS <80ms + screen for previous MI, BBB, or LV hypertrophy
Urine dipstick (sepsis)
Urinalysis (evidence of CKD to guide management between DOAC and Warfarin) + Toxicology (sympathetomimetics)

Bloods:
FBC - Anaemia, infection, low platelets if DIC, infection, sepsis)
CRP - raised in infl. + inf.
U&E - Hypomagnesia + hyper/hypokalaemia + medications
TFTs - hyperthyroidism
Troponin + CKMB (ischaemia as a cause or result of arrhythmia)
BNP - HF in severe arrhythmia
HbA1c and Lipid profile (RFs)

Imaging:
CXR - sx of HF (ABCDE)
ECHO - TTE - atrial/ventricular size (LA enlargement/LV hypertrophy), RV systolic pressure, valvular involvement, pericardial disease - TOE - LA (appendage) thrombus, Rule out vegetations in IE

Procedure: Exercise stress test - helps identify ischaemia

Question 14

In the management of A.fib, what is meant by recent onset A.fib

Answer 14

A.fib sx <48 hours

Question 15

How would you determine if A.fib is valvular or not?

Answer 15

TOE ECHO

Question 16

How is long term anticoagulation in A.fib decided on?

Answer 16

CHADs VASC

Question 17

Run me through the CHADs VASc score

Answer 17

Question 18

The management plan for A.fib is typically composed of 3 components: Rate control, rhythm control, and anticoagulation.

How would you choose which anticoagulant to give in recent onset vs not? Go through it all

Answer 18

If recent onset A.fib <48 hours -> Unfractionated heparin before cardioversion

Chronic
DOAC in all cases except CKD, valvular A.fib or prosthetic valve

2 strategies:
Conventional: 3 weeks DOAC before cardioversion, 4 weeks after, then based off of CHADS VASc

TOE strategy: TOE performed for LA (appendage) thrombus

If no LAA thrombus -> immediate unfractionated heparin before cardioversion (so we dont wait for a thrombus to pop up)

If LAA thrombus -> DOAC/warfarin for 3 weeks -> Check again. If gone, immediate heparin and cardioversion (likke before). If still present, Long term anticoagulation based off of CHADS VASc

Question 19

The management plan for A.fib is typically composed of 3 components: Rate control, rhythm control, and anticoagulation.

How will you manage rate control acutely?

Answer 19

acute => A.fib sx <48 hours => recent onset A.fib

If no other disease, HTN, or HFpEF: Beta blocker -> CCB -> Amiodarone

If LV dysfunction/HF: Beta blocker (metoprolol not bisop) -> Digoxin-> Amiodarone

If COPD: CCB (non-dihydro like the rest)

Question 20

What medication regime is required alongside DC cardioversion in any case? be very specific (not doses tho)

Answer 20

Anticoagulation with Unfractionated heparin in the acute case
DOAC 3 weeks before and 4 weeks after
Warfarin 3 weeks before and 4 weeks after if CKD or valvular A.fib

+

Sedation with Midazolam or Propafol
Anaglesia with Morphine or Fentanyl

+/- Amiodarone as an adjunct up to 1 year post-cardioversion

Question 21

In the management of A.fib, what are the indications for DC cardioversion

Answer 21

1) Haemodynamically unstable patient
2) Recent onset A.fib <48 hours
3) Anticoagulation for 3 weeks prior + TOE shows no signs of thrombus

Question 22

Why can cardioversion just be done acutely without the need to perform an ECHO, or 3 weeks of anticoagulation ahead of time etc…

Answer 22

in recent onset A.fib, there is not enough time for a thrombus to form and hence the risk of VTE is relatively small

Question 23

A patient presents to you and is not haemodynamically stable. The consultant asks you to prepare them for DC cardioversion. You know that you need to give them an anticoagulant. What anticoagulant are you giving them? when are you giving it?

Answer 23

Unfractionated heparin immediately before

Question 24

The pill in the pocket approach is given to patients with A.fib for rate control. What medications would be given in this case?

The pill in the pocket approach requires evidence of no structural heart disease. How will you know?

Answer 24

Class 1c antiarrhythmetics (slow ass/dissociation)
=> Flecainide or Propafenone

ECHO

Question 25

The management plan for A.fib is typically composed of 3 components: Rate control, rhythm control, and anticoagulation. How will you manage Rhythm control acutely?

Answer 25

acute => A.fib sx <48 hours => emergency => ABCDE call for help First check if the patient is haemodynamically stable If not -> Immediate unfractionated heparin -> Cardioversion If haemodynamically stable, the patient and physician will decide if they would prefer electrical or pharmacological management. For electrical it is an elective cardioversion but needs 3 weeks DOAC/Warfarin For pharmacological: Based on evidence of structural heart disease from ECHO: If none: Pill in pocket Class Ic (Flecainide, Propafenone) -> IV Ic, or III (Ibutilide, Vernakalant) -> IV amiodarone (class III) If moderate structural heart disease: IV class III (Ibutilide, Vernakalant) -> IV amiodarone If severe -> IV amiodarone Notice how each just removes the initial step

Question 26

The management plan for A.fib is typically composed of 3 components: Rate control, rhythm control, and anticoagulation. How would you manage rate control in a chronic setting such as OPD?

Answer 26

Beta blocker -> CCB if contra indicated As always non-dihydro CCB

Question 27

The management plan for A.fib is typically composed of 3 components: Rate control, rhythm control, and anticoagulation. How would you manage rhythm control chronically?

Answer 27

You dont, once it has been over 12 months, rhythm control is ceased and focus becomes on anticoagulation

Question 28

In a refractory case where all else has failed in the long term management of A.fib. What surgical options remain?

Answer 28

Radiofrequency ablation Maze procedure (not in the acute setting)

Question 29

What is a Maze procedure?

Answer 29

Incisions or ablations in the atria forming a maze to disrupt abnormal electrical activity that may cause A.fib Note: Mini-Maze also exists where radiofrequency or cryoablation is used hence bypassing the need for open heart surgery

Question 30

A patient is on their way by ambulance complaining of palpitations that started 15 hours ago and hasnt stopped/. Paramedics say the ECG is showing tachycardia, no P waves, fibrillation waves, and a narrow QRS. What your full management approach?

Answer 30

acute => A.fib sx <48 hours => recent onset A.fib Rate control: If no other disease, HTN, or HFpEF: Beta blocker -> CCB -> Amiodarone If LV dysfunction/HF: Beta blocker (metoprolol not bisop) -> Digoxin-> Amiodarone If COPD: CCB (non-dihydro like the rest) Rhythm control: First check if the patient is haemodynamically stable If not -> Immediate unfractionated heparin -> Cardioversion If haemodynamically stable, the patient and physician will decide if they would prefer electrical or pharmacological management. For electrical it is an elective cardioversion but needs 3 weeks DOAC/Warfarin For pharmacological: Based on evidence of structural heart disease from ECHO: If none: Pill in pocket Class Ic (Flecainide, Propafenone) -> IV Ic, or III (Ibutilide, Vernakalant) -> IV amiodarone (class III) If moderate structural heart disease: IV class III (Ibutilide, Vernakalant) -> IV amiodarone If severe -> IV amiodarone Anticoagulation: In the acute setting it is just unfractionated heparin prior to cardioversion if present

Question 31

A patient presents to the OPD after being referred by her GP complaining of palpitations for the past year and an ECG showing tachycardia, no P waves, fibrillation waves, and a narrow QRS. Records show that she has been admitted after 3 episodes of syncope due to this yet has not resolved. What will you prescribe to this patient

Answer 31

This is a chronic case with permanent A.fib that hasnt resolved on previous admissions where it can be assumed cardioversion was administered or given. In simple terms, acute is <48 hrs and chronic is >48 hours yet in a discussion know that the following treatment is given once the decision has been made to stop rhythm control. If there is still rhythm control indicated then treat as acute elective route (based on structural heart disease on ECHO) Lifestyle: Referral to dietician for weight loss, reduced cholesterol and salt intake for HTN Smoking cessation: Quit.ie, Patient education, NRT, Varenicline and Bupropion Reduce alcohol intake to 14U, education, patient support groups (AA), Disulfiram, Acamprosate Physiotherapy for exercise and rehabilitation Strict BP and glycaemic contro Rate control: Beta blocker -> CCB if contra indicated As always non-dihydro CCB Anticoagulation: DOAC in all cases except CKD, valvular A.fib or prosthetic valve 2 strategies: Conventional: 3 weeks DOAC before cardioversion, 4 weeks after, then based off of CHADS VASc TOE strategy: TOE performed for LA (appendage) thrombus If no LAA thrombus -> immediate unfractionated heparin before cardioversion (so we dont wait for a thrombus to pop up) If LAA thrombus -> DOAC/warfarin for 3 weeks -> Check again. If gone, immediate heparin and cardioversion (likke before). If still present, Long term anticoagulation based off of CHADS VASc Surgical: Radiofrequency ablation Maze procedure

Question 32

A patient is on their way by ambulance complaining of palpitations that started 15 hours ago and hasnt stopped/. Paramedics say the ECG is showing tachycardia, no P waves, fibrillation waves, and a wide QRS >120ms. Why might they have a wide QRS?

Answer 32

Just like in SVT that would indicate there is also a BBB or WPW. Recall range of QRS is 80-100 but some sources say 60-120

Question 33

What are the complications of Atrial Fibrillation?

Answer 33

1) Thromboembolic: Stroke/TIA, mesenteric ischaemia, critical limb ischaemia, PE... 2) HF 3) Dilated cardiomyopathy 4) Bradycardia and hypotension (meds) 5) Death

Question 34

What is Virchow's Triad?

Answer 34

Virchows triad: 3 primary factors cause thrombus formation 1) Endothelial injury 2) stasis of blood flow 3) hypercoagulability

Question 35

What is the typical rate of atrial depolarisation in Atrial flutter

Answer 35

around 300 (240-340)

Question 36

If atrial fibrillation is irregularly irregular, what is Atrial flutter?

Answer 36

Regularly irregular

Question 37

The etiology of Atrial flutter is similar to A.fib but what is interesting to note is that atrial flutter is very uncommon in a structurally normal heart. Define Atrial Flutter

Answer 37

Arrhythmia characterised by rapid, !!!regular atrial depolarisations at about 300bpm and a regular ventricular rate due to X:1 conduction

Question 38

You are asked to perform an ECG on a patient with palpitations. What findings would be consistent with with atrial flutter

Answer 38

Atrial rate about 300 in a sawtooth pattern P waves absent Narrow complex <0.8 X:1 conduction across AV node

Question 39

Atrial flutter is often described as X:1 sawtooth pattern. What are the most common values for X

Answer 39

Even>Odd => 2:1, 4:1, 3:1, 5:1

Question 40

What is the sawtooth pattern actually?

Answer 40

Flutter waves (get it?) Its the same thing as in atrial fibrillation, p waves are replaced with fibrillation waves

Question 41

When performing an ECG for any arrhythmia, you are typically looking for the specific findings related to common diagnoses such as A.fib and atrial flutter, or something like SVT or VT. What are some other things to look for that are relevant in any arrhythmia? (give the specific ECG findings for each think you're looking to screen for)

Answer 41

Previous MI: Pathological Q waves in the affected leads indicates necrotic tissue LV hypertrophy: Prolonged P waves in I Tall R waves in II Left axis deviation Bundle Branch Block: WILLIAM MARROW in V1 and V6 (explains widened QRS in arrhythmias)

Question 42

The investigations for Atrial flutter are the same as that for A.fib except the specific ECG findings. What is the full management algorithm for Atrial flutter?

Answer 42

Same principles as A.fib Rate control: Beta blocker (Class II) -> Non-dihydro CCB (IV) Anticoagulation: same principle as A.fib. DOAC in all cases except CKD, valvular A.fib or prosthetic valve !!Anticoagulation must be started 3 weeks prior to rhythm control + TOE to rule out LA (appendage) thrombus Rhythm control: Due to the high rate of recurrence in A.flutter, it is preferrable to perform surgical tx first 1) Radiofrequency catheter ablation 2) Class III - Amiodarone, Sotalol 3) Class Ic - Flecainide/Propafenone

Question 43

A good question to ask to patients who are obese and CVD history is whether they use a CPAP at night. What factors lead to the formation of a thrombus in cardiovascular disease?

Answer 43

Thrombus => based on Virchow's Triad 1) Endothelial injury (post-MI) 2) Stasis (Wall motion abnormality post-MI)/Turbulent flow (A.Fib) 3) +/- Hypercoagulability (whether genetic or medication induced or from RF of CVD)