Management of atrial fibrillation based on guidelines – part I

Management of atrial fibrillation based on guidelines – part I

The important guidelines on the management of atrial fibrillation (AF) which have been published during the last one year are the European guidelines 2010 [Camm AJ et al. Guidelines for the management of atrial fibrillation. European Heart Journal (2010) 31, 2369–2429], 2011 ACCF/AHA/HRS focussed updates on the management of atrial fibrillation [Fuster V et al. J. 2011 ACCF/AHA/HRS Focused Updates Incorporated Into the ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation. J Am. Coll. Cardiol. 2011;57;e101-e198 and Wann LS et al. 2011 ACCF/AHA/HRS Focused Update on the Management of Patients With Atrial Fibrillation. Circulation. 2011;123(1):104-23] and the 2011 ACCF/AHA/HRS Focused Update on the Management of Patients With Atrial Fibrillation (Update on Dabigatran) [Wann LS et al. J. Am. Coll. Cardiol. 2011;57:1330-1337].

Clinical events affected by atrial fibrillation

Death rate is almost doubled in those with atrial fibrillation, with the actual mortality varying, depending on the various comorbidities. Stroke is also definitely more frequent in patients with atrial fibrillation and the magnitude of the stroke is more severe in the presence of atrial fibrillation. The frequency of hospitalisations is increased in patients with atrial fibrillation. The quality of life and exercise tolerance have shown a wide variation in various studies. While many with atrial fibrillation are asymptomatic some feel distressing palpitations and deterioration in quality of life. Worsening of left ventricular function with tachycardiomyopathy and acute left ventricular failure can occur with atrial fibrillation. This depends partly on the ventricular rate and on the severity and type of underlying heart disease if any.

Conditions predisposing to atrial fibrillation

A wide range of conditions can predispose to atrial fibrillation, ranging from conditions which cause atrial dilatation to those which alter the electrical properties of the heart. Hypertension, diabetes mellitus, obesity, valvular heart disease, coronary artery disease, chronic obstructive pulmonary disease, renal disease, thyroid disorders including subclinical hyperthyroidism and primary electrical disorders of the heart or cardiac channelopathies, all can predispose to atrial fibrillation.

European Heart Rhythm Association (EHRA) scoring for AF related symptoms

EHRA score for symptoms related to atrial fibrillation are similar to the New York Heart Association functional classification.
EHRA I: No symptoms
EHRA II: Mild symptoms which do not affect the normal daily activities
EHRA III: Severe symptoms affecting the normal daily activities
EHRA IV: Disabling symptoms causing discontinuation of normal daily activities

Types of atrial fibrillation based on duration

First diagnosed AF: Atrial fibrillation diagnosed for the first time, irrespective of the severity or duration of symptoms.
Paroxysmal AF: Paroxysmal AF is self terminating AF which may last upto 7 days, but usually terminates within 48 hours. Recurrent episodes may occur. But the period of of 48 hours is critical because AF beyond 48 hours needs consideration anticoagulation and the chance of spontaneous termination becomes lower.
Persistent AF: Persistent AF is one which persists more than 7 days or needs termination by pharmacological or electrical cardioversion.
Long standing persistent AF: This terminology is applied when atrial fibrillation persists for one year or more, when a rhythm control strategy is adopted.
Permanent AF: This is the situation when the arrhythmia is accepted by the patient and the physician and rhythm control measures are not pursued by definition. If rhythm control strategy is adopted later, it is redesignated as long standing persistent AF.

Initial evaluation of patients with atrial fibrillation

Initial evaluation of a patient presenting with atrial fibrillation should include a targeted history and physical examination to look for underlying heart disease and potential predisposing factors for atrial fibrillation. Holiday heart syndrome following an alcoholic binge should also be considered in relevant situations, especially when a patient presents to the emergency room with atrial fibrillation. The presence of atrial fibrillation should be documented electrocardiographically and further ECGs may be needed if the arrhythmia has subsided at the time of recording, when the history is suggestive. Holter monitoring is useful in this context and will also document clinically silent atrial fibrillation. Follow up Holter monitoring is sometimes useful in documenting the efficacy of treatment as well as safety in excluding episodes of significant bradycardia. An echocardiogram will be needed in most cases to assess underlying heart disease and ventricular function. Ancillary investigations like thyroid function tests may ordered when deemed essential. Exercise testing is sometimes useful in assessing the response of ventricular rate in the presence of medications for rate control.