Atrial Fibrillation

- Characterized by an irregular and often rapid heartbeat

- strongly associated with heart failure, coronary artery disease, valvular heart disease, diabetes mellitus, hypertension

History:

 - 90% of AF are asymptomatic

 - wide range of symptoms: palpitations, dyspnoea, fatigue, dizziness, angina, decompensated heart failure

 - history should include: 

                  + type, duration and frequency of symptoms

                  + precipitating factors

                  + modes of termination

                  + documentation of prior use of anti-arrhythmics and rate-controlling agents

                  + presence of underlying heart disease

                  + history of any previous surgical or percutaneous AF ablation procedures

Physical examination:

 - Vital signs: irregularly irregular pulse, tachycardic

 - Head and neck: exophthalmos, thyromegaly, elevated jugular venous pressure, cyanosis, carotid artery bruits

 - Pulmonary: rales, pleural effusion, wheeze

 - Cardiac: displaced apex beat, prominent P2 points

 - Abdomen: ascites, hepatomegaly, hepatic capsular tenderness, splenic infarct

 - Lower extremities: cyanosis, clubbing, oedema, pulseless extremity

 - Neurologic: signs of transient ischaemic attack or cerebrovascular accident, increased reflex

Differential Diagnosis:

- Atrial flutter

- Atrial tachycardia

- Atrioventricular Nodal Reentry Tachycardia

- Multifocal Atrial Tachycardia

- Paroxysmal Supraventricular Tachycardia

- Wolff-Parkinson-White Syndrome

Investigation: 

1) Electrocardiography

    

                            - Rate irregularly irregular, 110-140 bpm

                            - No P waves

                            - Irregular baseline

                            - Normally shaped QRS complexes

                            - Lead V1 - no flat baseline between P waves

2) Laboratory studies

• Complete blood count - look for anaemia or infection
• Serum electrolyte and blood urea nitrogen/creatinine ratio - electrolyte disturbances or renal failure
• Cardiac enzymes - CK and/ or troponin level - investigate myocarcial infaction
• B-type Natriuretic Peptide - to evaluate congestive heart failure
• D-dimer - if the patient has risk factors for pulmonary embolism
• Thyroid function studies - to look for thyrotoxicosis
• Digoxin level - toxicity level

3) Echocardiography

• evaluate for valvular heart disease
• evaluate for left and right size
• evaluate for left ventricular size and function and left ventricular hypertrophy
• evaluate for pericardial disease

4) Computed Topography and Magnetic Resonance Imaging

• Chest CT angiography to rule out pulmonary embolism
• 3D imaging technique are helpful to evaluate atrial anatomy for intervention

5) Chest radiography

• evidence of congestive heart failure
• signs of lung pathology i.e. pulmonary embolism, pneumonia

6) Stress test - to rule out inschemia