Introduction to afib, Epidemiology of afib, etiology of afib, Clinical presentation of people with afib, Investigation and management AF related outcomes and complications and differential Diagnosis

1. Atrial Fibrillations
Dr Nabeya Viktor Kasi
Medical Doctor
1

2. Outlines
• Introduction
• Epidemiology
• Etiology
• Clinical presentation
• Investigation
• Management
• AF related outcomes and complications
• Differential Diagnosis
• References 2

3. Introduction
• Atrial fibrillation (AF) poses significant burden to patients,
physicians, and healthcare systems globally
• The complexity of AF requires a multifaceted, holistic, and
multidisciplinary approach to the management of AF patients
3

4. Definition
• A supraventricular tachyarrhythmia with uncoordinated atrial
electrical activation and consequently ineffective atrial
contraction. Electrocardiographic characteristics of AF include
Irregularly irregular R-R intervals (when atrioventricular
conduction is not impaired)
Absence of distinct repeating P waves, and
Irregular atrial activations 4

5. 5

6. Epidemiology
• Most frequently encountered cardiac arrythmia
• Incidence - increases with age
• The lifetime risk of Afib among individuals > 40 years is 1 in 4.
• >95% of individuals with Afib are ≥ 60 years
• Prevalence - 1% of US population
6

7. Mechanism
• SA node is a dominant pacemaker of the heart which sends
impulses to the atrium causing atrial contraction
• From the SA nose, the impulse arrives at the AV node.
• From the AV node, the impulses travels rapidly along the bundle
of HIS – bundle branches and purkinje fibers where the impulse
causes ventricular contraction
7

8. • Afib is as a result of an initial trigger thought to be from
Ectopic foci firing rapidly from the pulmonary vein
or
Single localized reentry circuit in the atrial myocardium
8

9. Etiology
• Cardiovascular
Advanced age
Hypertension
DM
Smoking
Obesity
Sleep Apnea
9

10. • Intrinsic Cardiac Disorder
Coronary artery disease
Valvular heart disease(esp mitral valve disease)
Congestive Heart Failure
Preexcitation tachycardia eg WPW syndrome
Sick Sinus syndrome (tachycardia-bradycardia syndrome)
Cardiomyopathies
Pericarditis 10

11. • Non cardiac disorders
Pulmonary disease- COPD, pulmonary embolism, pneumonia
Hyperthyroidism
Catecholamine release and/or increased sympathetic activity
Electrolyte imbalances
Drugs
11

12. Holiday heart syndrome
Chronic kidney disease
• Genetic
• Neurological disorder
• Idiopathic
12

13. Classification
• Hemodynamic Stability
Unstable Afib
Stable afib
• Ventricular Rate
Afib with rapid ventricular response
Afib with slow ventricular response
13

14. Classification by onset
Atrial fibrillation is referred to as recurrent when a patient has two or more
episodes. The patterns of atrial fibrillation include:
First diagnosed/new onset AF - AF not diagnosed before, irrespective of its
duration or the presence/severity of AF-related symptoms.
• Paroxysmal AF - If recurrent AF reverts spontaneously within seven days
• Persistent AF - recurrent AF persisting needing either pharmacological or
electrical cardioversion and it last more than seven days
14

15. • Long-standing persistent AF: AF that has been present for more than 12
months, either due to the failure of initiation of pharmacological
intervention or failure of cardioversion
• Permanent AF: It is the type where a decision has been made to abort all
therapies because the rhythm is unresponsive
15

16. • Method of detection
Clinical afib
Subclinical afib
• Mitral valve involvement
Valvular afib
Nonvalvular afib
16

17. Triggers of Atrial Fibrillation
• Several triggers excites focus in the atrial most commonly around the
pulmonary veins and allows for an unsynchronized firing of electrical
impulses leading to fibrillations. These are;
Atrial ischemia
Inflammation
Alcohol or illicit drug use
Hemodynamic stress
17

18. Endocrine disorders
Advanced age
Genetic factors
18

19. Clinical Presentation
19
• Asymptomatic
Hemodynamically stable
• Symptomatic
Palpitations
Dyspnea
Fatigue
Chest tightness/pain, poor effort tolerance, dizziness, syncope, disordered
sleep

20. • Hemodynamically unstable
Syncope
Symptomatic hypotension
Acute HF, pulmonary edema
Ongoing myocardia ischemia
Cardiogenic shock
20

21. Symptoms and quality of life
• As symptoms related to AF may range from none to disabling,
and rhythm control treatment decisions (including catheter
ablation) are influenced by symptom severity, symptom status
should be characterized using the European Heart Rhythm
Association (EHRA) symptom scale
21

22. 22

23. Investigations
• FBC
• Basic metabolic panel
Serum elctrolytes
Serum glucose
BUECR
• Thyroid function test
• LFT
• Troponin levels 23

24. • BNP or NT-proBNP
• D-dimer
• Serum toxicology and/or urine toxicology
• Chest xray, CT scan(CTA or Head CT)
• ECG
• Echo
24

25. • ECG finding of atrial Fibrillation
typical narrow complex "irregularly irregular" pattern
No distinguishable p wave
Typically narrow QRS complex (<0.12 seconds)
ventricular rate usually ranges between 80 and 180/min
Left ventricular hypertrophy
25

26. 26

27. • Transthoracic echocardiography(TTE) is helpful for the following
To evaluate for valvular heart disease
To evaluate atrial and ventricular chamber and wall dimension
To estimate ventricular function and evaluate for ventricular
thrombi
To estimate pulmonary systolic pressure
27

28. • Transesophageal echocardiography (TEE) is helpful for the following
To evaluate for atrial thrombus
To guide cardioversion
28

29. • Holter Monitor
Establish a diagnosis in cases of paroxysmal AF which are not
evident on presentation
Evaluate rate control
29

30. Management
• It starts with the history and physical examination
• Initial history and physical examination should include the
following
Documentation of clinical type of AF
Assessment of type, duration, frequency of symptoms
Assessment of precipitating factors
30

31. Assessment of modes of termination
Documentation of prior use of antiarrhythmics and rate controlling agents
Assessment of presence of underlying heart disease
Documentation of any previous surgical or percutaneous AF ablation
procedure
ABC
Vital signs(HR, BP, RR, oxygen saturation)
31

32. Approach
• Unstable patients: emergent electrical cardioversion
• Stable patients: The goal is to control heart rate and/or rhythm.
Acute management
Long-term management:
• The choice of rate control versus rhythm control depends on
institutional preferences and individual patient risk factors
32

33. • All patients
• Consider referral to cardiology.
• Correct reversible causes and/or treatable conditions, e.g.
hyperthyroidism, electrolyte imbalances
• Prevention of thromboembolic complications: Consider indications for
anticoagulation
• Encourage lifestyle modifications that reduce the risk of recurrence and
decrease the likelihood of complications, e.g. weight loss, exercise, and
reducing alcohol consumption 33

34. Acute
• Hemodynamically unstable
• Immediate synchronized cardioversion
• Urgent cardiology consult
• ICU/CCU transfer
• Identify and treat the underlying cause
• Continuous cardiac telemetry
34

35. • Hemodynamically stable
• Afib with normal heart rate, consider indications for nonemergency cardioversion (e.g., first
episode).
• Refer to cardiology for long-term management with either rhythm or rate control
• Afib with RVR
 < 48 hours duration: Consider rate or rhythm control
 > 48 hours: rate control
• ICU/CCU consult and transfer if the patient has a refractory rapid ventricular rate 35

36. Rate control
• The goal is to normalize the ventricular heart rate to reduce symptoms.
• Target resting heart rate
< 110/minute: for patients who remain asymptomatic or have normal
LV systolic function
< 80/minute: for patients who continue to be symptomatic with a lenient
rate
• Consider rate control strategy especially in elderly patients
• Contraindication: Afib due to preexcitation syndromes 36

37. Pharmacological options
37
• First line
Beta blockers (eg metoprolol, atenolol, propranolol)
Preferred when afib is due to hyperthyroidism and in pregnant patients
Avoid in patients with COPD
• Nondihyropyridine calcium channel blockers (eg diltiazem, verapamil)
Avoid in patients with decompensated heart failure (LV systolic dysfunction/low
ejection fraction)
Can be safely used in heart failure with preserved normal LV systolic function

38. • Second-line: digoxin preferred initial therapy for patients
with ADHF
• Third-line: amiodarone typically reserved for patients in whom all
other options have failed
38

39. Rhythm control
• Goal
Termination of atrial fibrillation
Restoration and maintenance of sinus rhythm
Symptom improvement
Prevention of atrial remodeling
39

40. Electrical Cardioverison
• Patients who are hemodynamically unstable, who have severe
dyspnea or chest pain with AF, or who have preexcited AF should
undergo urgent cardioversion.
• Direct current (DC) cardioversion is the delivery of electrical
current that is synchronized to the QRS complexes; it can be
delivered in monophasic or biphasic waveforms.
40

41. Pharmacological cardioversion
• Pharmacological cardioversion agents for Afib
• The following are inpatient regimens of IV or oral antiarrhythmics;
Flecainide
Dofetilide
Propafenone
Amiodarone
41

42. Pill in pocket approach
• A single, self-administered dose of an anti-arrhythmic (e.g., flecainide ,
sotalol) used outside of the hospital to terminate atrial fibrillation
• Typically given in conjunction with a beta blocker or ndHP CCB
• May be used in patients with recent onset of Afib with infrequent episodes
and no history of structural or ischemic heart disease
• Patients should be monitored on the regimen in the hospital environment
before they can self-administer.
42

43. Surgical options
• AV nodal ablation and implantation of a permanent ventricular
pacemaker
Irreversible procedure
Eliminates the need for rate-controlling medications but leads to
lifelong dependence on a pacemaker
43

44. 44

45. Risk management assessment
• The CHA2DS2-Vasc score uses a point system to determine yearly
thromboembolic risk. Two points are assigned for a history of stroke
or TIA, thromboembolism, or age of 75 years or older, and one point
is given for age 65-74 years or a history of hypertension, diabetes,
heart failure, arterial disease (coronary artery disease, peripheral arterial
disease, or aortic plaque), or female sex
45

46. 46

47. CHA2 DS2-VASc Score Recommended Therapy
0 No therapy
1
No therapy, or aspirin 81-325 mg daily, or
anticoagulation therapy
(eg, warfarin [international normalized ratio
(INR) goal 2-3], dabigatran, rivaroxaban,
apixaban, edoxaban)
≥2
Anticoagulation therapy (eg, warfarin [INR goal
2-3], dabigatran, rivaroxaban, apixaban,
edoxaban)
47

48. • The major adverse effect of anticoagulation therapy with warfarin is
bleeding. Factors that increase this risk include the following:
• History of bleeding
• Age older than 75 years
• Liver or renal disease
• Malignancy
• Thrombocytopenia or aspirin use
48

49. • Diabetes mellitus
• Hypertension
• Anemia
• Prior stroke
• Genetic predisposition
• Supratherapeutic INR
49

50. • Several risk models have been introduced. The risk model called
HEMORR2HAGES assigns points to risk factors, as follows :
• History of bleeding (2 points)
• Hepatic or renal disease (1 point)
• Alcohol abuse (1 point)
• Malignancy (1 point)
• Older age (>75 years) (1 point)
50

51. • Reduced platelet count or function, including aspirin therapy (1 point)
• Hypertension (1 point)
• Anemia (1 point)
• Genetic predisposition (1 point)
• Excessive fall risk (1 point)
• Stroke (1 point)
51

52. Has-bled
52

53. Newer oral anticoagulants versus warfarin
• There are several advantages of using the noac over warfarin which are:
• Predictable pharmacologic profiles with fewer drug–drug interactions, and dietary
effects
• Lower risk of intracranial bleeding
• Rapid onset and offset of action, with no need for bridging with parenteral
anticoagulant therapy during initiation or after interruption
• No need for periodic INR testing
• Superiority to warfarin for reducing the risk of thromboembolic events with
dabigatran 150 mg BID and apixaban 53

54. Disadvantages of the newer oral anticoagulants
include the following
• Requires strict compliance, because missing even a single dose could result in a period without
anticoagulation
• No FDA-approved reversal agents for rivaroxaban, apixaban, and edoxaban (currently under clinical
trials)
• Limited safety profile data for patients with severe kidney failure
• No data for their use in the presence of mechanical heart valves (dabigatran was associated with
increased risk of thromboembolic complications in patients with mechanical heart valves in the RE-
ALIGN trial) or valvular AF, due to hemodynamically significant mitral stenosis
• No data for their use in pregnant or lactating women, in children, or in patients with a recent stroke
(≤7-14 days), reversible causes of AF, severe increase in blood pressure, and significant liver disease
• Lack of reliable blood tests to ascertain therapeutic effect or toxicity 54

55. 55

56. 56
AF related
outcomes
Frequency in AF Mechanism(s)
Death 1.5 – 3.5 fold increase Excess mortality related to
HF, comorbidities
Stroke
Stroke 20 – 30% of all ischemic strokes, 10% of
cryptogenic strokes
Cardioembolic or relayed to comorbid vascular
atheroma
LV dysfunction/
Heart Failure
In 20 – 30% of AF patients Excessive ventricular rate, Irregular ventricular
contractions, A primary underlying cause of AF
Cognitive decline/
vascular dementia
1.4/1.6 (irrespective of stroke history) Brain white matter lesions, inflammation,
Hypoperfusion, Micro-embolism
Depression Depression in 16 – 20% (even suicidal
ideation)
Severe symptoms and decreased quality of life, Drug
side effects
Impaired quality of
life
>60% of patients Related to AF burden, comorbidities
Hospitalization 10 – 40% annual hospitalization rate AF management related to HF, MI or AF related
symptoms, Treatment associated complications

57. Complications
• Systemic thromboembolism
CVA or TIA
Pulmonary Embolism
Splenic Infarct
• Tachycardia induced cardiomyopathy
• Cardiogenic shock
57

58. Differential Diagnosis
• Atrial Flutter
• Atrial Tachycardia
• Multifocal Atrial Tachycardia
• Wolf-Parkinson-White syndrome
• Atrioventricular nodal reentry tachycardia.
58

59. Atrial Flutter
• It is a cardiac arrythmia characterized by atrial rates of 240 to
400bpm usually with some degree of atrioventricular block
• ECG
Sawtooth flutter(f) waves often visualized in leads II, III, avF or
V1
Regularly irregular rhythm
59

60. Atrial Tachycardia
• Is a type of supraventricular tachycardia that does not require the
atrioventricular junction, accessory pathways or ventricular tissue for
its initiation and maintenance
• ECG
Rate of 150bpm
Negative waves in leads III and avF
Persist despite the atrioventricular block
60

61. Multifocal atrial tachycardia
• Irregular supraventricular tachycardia characterized by three
distinct p wave morphologies and or pattern of atrial activation at
different rate
• The rhythm is always irregular
61

62. Wolff-Parkinson-White syndrome
• Congenital condition involving abnormal conductive tissue between
the atrial and the ventricles that provides a pathway for a reentrant
tachycardia circuit in association with supraventricular tachycardia
• Chest findings are mostly normal
• Features associated with wpw syndrome includes;
Hypertrophic Cardiomyopathy(AMPK mutation)
Ebstein anomaly
62

63. • ECG
Shortened PR interval
A slow rise of the initial upstroke of the QRS complex – delta
wave
Widened QRS complex (total duration > 0.12 secs)
ST segment – T wave changes
63

64. • Echo
To evaluate left ventricular function
To evaluate septal thickness
To evaluate for wall motion abnormalities
Stress testing and electrophysiologic studies could be done
64

65. Thank you
65

66. References
• Nesheiwat, Z., Goyal, A. and Jagtap, M., Continuing Education
Activity.
• Ralston, S.H., Penman, I.D., Strachan, M.W. and Hobson, R. eds.,
2018. Davidson's Principles and Practice of Medicine E-Book.
Elsevier Health Sciences.
• Rosenthal, L., McManus, D.D. and Sardana, M., 2018. Atrial
fibrillation treatment & management.
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67. •Mortality meeting
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