This document discusses mechanisms of cardiac arrhythmia including alterations in impulse initiation, afterdepolarizations, and abnormal impulse conduction. It then focuses on atrial fibrillation, describing it as the most common sustained arrhythmia characterized by rapid and irregular atrial waves and irregular ventricular response. The document classifies atrial fibrillation as paroxysmal, persistent, or permanent and lists various etiologies including valvular heart disease, heart failure, cardiomyopathy, surgery, and medications. It outlines the clinical features and management of atrial fibrillation including rate control, rhythm control, and prevention of embolization.

1. ARRYTHEMIA
By – Kifle alamirew(MD)1

2. MECHANISMS OF CARDIAC ARRYTHMIA
1. Alterations in Impulse Initiation: Automaticity
2. Afterdepolarizations and Triggered
Automaticity
3. Abnormal Impulse Conduction: Reentry
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3. CONT’D…
 Arrhythmia can be
 Bradyarrythmia
 Sinus bradyarrythemia
 Atriventricular block: 1st ,2nd and 3rd degree block
 Tachyarrhythmia
 Sinus tachycardia
 SVT
 Atrial fibrillation
 Atrial flutter
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4. ATRIAL FIBRILLATION
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5. ATRIAL FIBRILLATION
 is the most common sustained arrhythmia
 is characterized by rapid and irregular atrial fibrillatory
waves at a rate of 350 to 600 impulses/minute and,
 in the presence of normal atrioventricular (AV) nodal
conduction, by an irregularly irregular ventricular
response of 90 up to 140 to 170 beats/min, but it may be
higher in some patients
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6. CONT…
 Classification of AF
 Paroxysmal (i.e., self-terminating) — AF is classified
as paroxysmal if episodes terminate spontaneously in
less than seven days, usually less than 24 hours.
 Persistent AF — AF is classified as persistent if it fails
to self-terminate within seven days. Episodes may
eventually terminate spontaneously, or they can be
terminated by cardioversion. A patient who has had
an episode of persistent AF can have later episodes of
AF that classify as paroxysmal (i.e., self-terminating in
less than seven days).
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7. CONT…
 Permanent AF — Permanent AF is considered to be
present if the arrhythmia lasts for more than one year
and cardioversion either has not been attempted or has
failed.
 "Lone" AF — "Lone" AF describes paroxysmal, persistent,
or permanent AF in individuals without structural heart
disease
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8. CONT…
Etiology
 Valvular heart disease
 Hypertensive heart disease
 Coronary heart disease
 Heart failure (10-30%)
 HCMP(HYPERTROPHY CARDIOMYOPATHY) (10-28%)
 Congenital heart disease
 Other types of cardiopulmonary disease
 Obesity
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9. CONT…
 Hyperthyrodism
 Surgery
 Inflammation and infection
 Autonomic dysfunction
 Other supraventricular tachyarrhythmias
 Diet
 Medications
 Genetics
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10. CONT…
 VHD and AF
 MS,MR, and TR — 70 percent
 MS and MR — 52 percent
 Isolated MS — 29 percent
 Isolated MR — 16 percent
 Isolated AS-1%
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11. CONT…
Clinical feature
 Asymptomatic
 Symptoms of underlying disease
 Symptoms directly related to AF
 The loss of atrial contractility
 The inappropriate fast ventricular response
 The loss of atrial appendage contractility and emptying leading to
the risk of clot formation and subsequent thromboembolic events
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12. CONT…
 Management
 Rate control
 Rhythm control
 Rate Vs Rhythm control
 Prevention of systemic embolization
 Nonpharmacologic therapy
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