Definition
- What is the most common arrhythmia?
- What are the types of atrial fibrillation?
- What is lone atrial fibrillation?
- Define palpitation.
- What is sinus tachycardia?
- What is sinus bradycardia?
Epidemiology
- –
Etiology and Pathophysiology
- What are the common causes of atrial fibrillation?
- What are the causes of temporary atrial fibrillation?
- What are the causes of irregularly irregular pulse?
- What are the causes of palpitation?
- Tell some common causes of sinus tachycardia?
- Tell some common causes of sinus bradycardia?
Clinical manifestations
- What are the common presentations of atrial fibrillation?
- What is the character of pulse in atrial fibrillation?
Examinations
- What will you get by examining this patient with atrial fibrillation?
- How can you differentiate between atrial fibrillation and multiple ectopics clinically?
Investigations
- What are the ECG findings in atrial fibrillation?
- How will you confirm your diagnosis?
Diagnosis
- What is your diagnosis?
- What is the underlying cause?
- Suppose no cause is identified even after full investigation, what do you call it?
Treatment
- Tell the outline of management of atrial fibrillation?
- How can you assess risk of thromboembolism in atrial fibrillation?
- What is the role of digoxin in atrial fibrillation?
- How will you manage the patient of lone atrial fibrillation?
- If a patient with atrial fibrillation is unconscious, what is the likely cause?
Complications
- What are the complications of atrial fibrillation?
Rimikri
SOLVES
Definition
What is cardiac arrhythmia?
An abnormality of the cardiac rhythm is called a cardiac arrhythmia.
* Kumar and Clark’s Clinical Medicine, 9th Edition Page: 962
Or, A cardiac arrhythmia is a disturbance of the electrical rhythm of the heart.
* Davidson’s Principles and Practice of Medicine, 22nd edition Page: 562
What are the types of arrhythmia?
There are two main types of arrhythmia:
- Bradycardia: the heart rate is slow (
- Tachycardia: the heart rate is fast (>100 b.p.m.)
* Kumar and Clark’s Clinical Medicine, 9th Edition
* Macleod’s Clinical Examination, 13th Edition Page: 111
What is sinus tachycardia?
Sinus rate >100 beats per minute (bpm) is sinus tachycardia.
* Pre-exam preparation for medicine, HN Sarker
What is sinus bradycardia?
Sinus rate
* Pre-exam preparation for medicine, HN Sarker
What is the most common arrhythmia?
Atrial fibrillation is the most common arrhythmia.
* Pre-exam preparation for medicine, HN Sarker
What is atrial fibrillation?
Atrial fibrillation (AF) is a complex arrhythmia characterised by both abnormal automatic firing and the presence of multiple interacting re-entry circuits looping around the atria.
Note: Further reaading on ‘automatic firing’ and ‘multiple interacting re-entry circuits looping’ at Davidson’s Principles and Practice of Medicine, 22nd edition Page: 565, 562
* Davidson’s Principles and Practice of Medicine, 22nd edition Page: 564
What are the types of atrial fibrillation?
- According to duration
- Paroxysmal (intermittent episodes which self-terminate within 7 days)
- Persistent (prolonged episodes that can be terminated by electrical or chemical cardioversion)
- Permanent
- According to heart rate
- Fast atrial fibrillation—Ventricular rate is >100/ minute
- Slow atrial fibrillation—Ventricular rate is <100/ minute.
* Pre-exam preparation for medicine, HN Sarker; Davidson’s Principles and Practice of Medicine, 22nd edition Page: 565
What is lone atrial fibrillation?
Atrial fibrillation having no cause and patient have structurally normal heart is known as ‘lone atrial fibrillation’.
This patient needs no anticoagulation because of low risk of thromboembolism. Aspirin may be used.
* Pre-exam preparation for medicine, HN Sarker
Define palpitation
Read details of palpitation at Symptoms of cardiovascular disease
Etiology and Pathophysiology
What are the common causes of atrial fibrillation?
The five common causes of atrial fibrillation are:
- Chronic rheumatic heart disease, particularly mitral stenosis
- Ischemic heart disease
- Hypertension
- Thyrotoxicosis
- Lone atrial fibrillation.
* Pre-exam preparation for medicine, HN Sarker
* Davidson’s Principles and Practice of Medicine, 22nd edition Page: 565
What are the causes of temporary atrial fibrillation?
- Acute MI
- Myocarditis
- Electrolyte imbalance
- Pneumonia and
- Cardiothoracic resuscitation
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 68
Tell some common causes of sinus tachycardia?
Some common causes of sinus tachycardia are:
- Anxiety
- Fever
- Anemia
- Heart failure
- Thyrotoxicosis
- Phaeochromocytoma
- Drugs—e.g. β -agonists (salbutamol).
Read details about pulse rate at Examination of cardiovascular system
* Pre-exam preparation for medicine, HN Sarker; Davidson’s Principles and Practice of Medicine, 22nd edition Page: 563
* Davidson’s Principles and Practice of Medicine, 22nd edition Page: 563
Tell some common causes of sinus bradycardia?
Some common causes of sinus bradycardia are:
- MI (especially inferior MI)
- Sinus node disease (sick sinus syndrome)
- Hypothermia
- Hypothyroidism
- Obstructive jaundice
- Raised intracranial pressure.
- Drugs—e.g. β -blockers, digoxin, and verapamil.
* Pre-exam preparation for medicine, HN Sarker; Davidson’s Principles and Practice of Medicine, 22nd edition Page: 563
Clinical manifestations
What are the common presentations of atrial fibrillation?
The common presentations of atrial fibrillation are:
- Palpitation
- Heart failure
- Thromboembolism, e.g. stroke.
* Pre-exam preparation for medicine, HN Sarker
* Macleod’s Clinical Examination, 13th Edition Page: 103
What are the causes of palpitation?
Read details of palpitation at Symptoms of cardiovascular disease
What is the character of pulse in atrial fibrillation?
Irregularly irregular pulse.
* Pre-exam preparation for medicine, HN Sarker
What are the causes of irregularly irregular pulse?
Read details of palpitation at Examination of cardiovascular system
Examinations
What will you get by examining this patient with atrial fibrillation?
We get by examining patients with atrial fibrillation are:
- Irregularly irregular pulse
- Pulsus deficit
- Absence of a-wave in JVP
- Variable intensity of first heart sound
* Pre-exam preparation for medicine, HN Sarker
How can you differentiate between atrial fibrillation and multiple ectopics clinically?
By doing physical exercise. Ectopics will disappear or diminished but atrial fibrilation will be more prominent.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 68
Investigations
What are the ECG findings in atrial fibrillation?
The ECG findings are:
- Absence of P-wave
- Presence of fibrillatory f-wave
- R-waves are irregular in space and amplitude
* Pre-exam preparation for medicine, HN Sarker
Figure: ECG of atrial fibrillation. A Note absolute rhythm irregularity and baseline undulations (f waves). B In chronic atrial fibrillation, the ventricular rate may be much slower, due to the effects of medication and AV nodal fatigue.
* Kumar and Clark’s Clinical Medicine, 9th Edition Figure: 23.46A; Davidson’s Principles and Practice of Medicine, 22nd edition Page: 565
How will you confirm your diagnosis?
By doing ECG.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 68
Diagnosis
What is your diagnosis?
Atrial fibrillation with fast/slow ventricular rate.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 68
What is the underlying cause?
I could not find any cause clinically, so I like to investigate to detect underlying cause.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 68
Suppose no cause is identified even after full investigation, what do you call it?
Lone atrial fibrillation.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 68
Treatment
Tell the outline of management of atrial fibrillation?
The outline of management are:
- Restoration of sinus rhythm (either by drug or DC shock)
- Flecainide (2 mg/kg over 30 mins, maximum dose 150 mg) can be used for pharmacological cardioversion and will restore sinus rhythm in 75% of patients within 8 hours.
- In patients with structural or ischaemic heart disease, intravenous amiodarone can be given via a central venous catheter.
- Maintenance of sinus rhythm
- Pharmacological cardioversion: Flecainide is 1st choice if no structural heart disease. IV amiodarone if structural heart disease.1
- Control of heart rate during atrial fibrillation
- β-blocker or rate-limiting Ca2+ blocker (verapamil or diltiazem) are 1st choice. If this fails, add digoxin.1
- Prevention of thromboembolism
- Either by warfarin or aspirin.
- Treatment of underlying cause.
* Pre-exam preparation for medicine, HN Sarker; Davidson’s Principles and Practice of Medicine, 22nd edition Page: 566;
1Oxford Handbook of Clinical Medicine, 9th Edition Page: 124
What is the role of digoxin in atrial fibrillation?
Digoxin controls heart rate but cannot convert atrial fibrillation to sinus rhythm.
* Pre-exam preparation for medicine, HN Sarker
How can you assess risk of thromboembolism in atrial fibrillation?
By using the CHADS score:
- Congestive heart failure (1 point)
- Hypertension (1 point)
- Age ≥ 75 (1 point)
- Diabetes mellitus (1 point)
- Stroke or transient ischemic attack (2 points)
Score: 0 = aspirin therapy only, 1= warfarin or aspirin, and ≥ 2 = warfarin.
* Pre-exam preparation for medicine, HN Sarker
* Davidson’s Principles and Practice of Medicine, 22nd edition Page: 567
How will you manage the patient of lone atrial fibrillation?
This patient needs no anticoagulation because of low risk of thromboembolism. Aspirin may be used.
* Pre-exam preparation for medicine, HN Sarker
If a patient with atrial fibrillation is unconscious, what is the likely cause?
Brainstem infarction (due to thromboembolism) or hemorrhage (use of anticoagulant).
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 68
Complications
What are the complications of atrial fibrillation?
- Thromboembolism – CVD, acute limb ischemia
- Heart failure.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 68
