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Atrial Fibrillation

Atrial fibrillation has a prevalence of 4 percent in the adult population. The prevalence of this arrhythmia increases with age, from less than 0.05 percent in patients 25 to 35 years of age to more than 5 percent in patients over 69 years of age. Atrial fibrillation is associated with an increased susceptibility to embolic stroke. The annual risk of stroke in patients with atrial fibrillation is 4.5 percent. Atrial fibrillation also can decrease exercise tolerance and has been associated with tachycardia-induced cardiomyopathy. Although many

Clinical evaluation

Atrial fibrillation (AF) may manifest only as fatigue caused by impaired cardiac output or the patient may have no symptoms. Palpitations, shortness of breath or chest pain may occur, and syncope may infrequently accompany AF. Symptoms of

The cause of the atrial fibrillation should be identified. Precipitating causes, such as hyperthyroidism, electrolyte abnormalities, and drug toxicity, should be excluded. Stimulant abuse, excess tobacco, alcohol, caffeine, chocolate, over-the-counter cold remedies, and street drugs should be sought. AF may be associated with a recent acute illness, such as pneumonia atrial fibrillation, fibrilation, atreal, palpitations, irregular heart beat.

Physical examination

The pulse is characterized by an irregular-irregular timing and amplitude. The rapid ventricular rate may cause hypotension and pulmonary congestion.

The patient should be examined for hypertension, valvular disease, pericarditis, coronary artery disease, hyperthyroidism, or chronic obstructive pulmonary disease. Murmurs and cardiac enlargement should be sought. Peripheral bruits may be a marker for associated coronary artery disease atrial fibrillation, fibrilation, atreal, palpitations, irregular heart beat.

Diagnostic evaluation

12-lead electrocardiogram reveals irregular R-R intervals with no P waves. The ventricular rate is irregularly, irregular and

Laboratory evaluation. Chest x-ray, electrolytes and screening labs, ECG, transesophageal echocardiogram, free T4, TSH,

Treatment of acute atrial fibrillation: rate and rhythm control

Patients who are unstable (ie, a heart rate of 150 or more with low blood pressure, angina pectoris, shortness of breath, decreased level of consciousness, shock, pulmonary congestion, congestive heart failure or acute myocardial infarction) during atrial fibrillation require immediate cardioversion using a 200-joule synchronized shock

Prevention of embolic events during cardioversion

Both electric and pharmacologic cardioversion carry a risk of embolic events, including stroke. Patients with persistent atrial fibrillation of unknown duration or more than 48 hours duration should be treated with anticoagulants for three weeks before

Pharmacologic methods of ventricular rate control

The first goals of therapy should be control of the ventricular rate. Intravenous calcium channel blockers and beta blockers have the advantage of rapid onset of action. Digoxin has a delayed onset of action of two hours. Digoxin is not effective in

Pharmacologic Methods of Acute Cardioversion

Type IA medications

Intravenous procainamide ( Procainamide injection) is effective for cardioversion in up to 60%. In one hour,

Quinidine ( Quinaglute). The conversion rate with oral quinidine is up to 60%. Torsades de pointes is a

Class IC Medications

Flecainide ( Tambocor). A single high-bolus dose of oral flecainide (less than

Propafenone ( Rythmol). High-dose (600 mg) oral propafenone has a conversion rate

Class III medications

Amiodarone ( Cordarone) does not appear to be effective in converting recent-onset atrial fibrillation to sinus rhythm. Oral

Sotalol ( Betapace) is not useful for the acute termination of atrial fibrillation. Sotalol and amiodarone slow conduction and

Ibutilide ( Corvert) is an intravenous class III antiarrhythmic agent. It is indicated for the acute termination of atrial fibrillation

Class IA and class IC agents are effective for acute termination of atrial fibrillation, with conversion rates of 60-80%. Although class III agents are useful as adjuncts to electric cardioversion and are effective in maintaining sinus rhythm, only ibutilide is useful for cardioversion