Identification of Atrial
Fibrillation
Atrial fibrillation (AF) is a supraventricular tachyarrhythmia
characterized by uncoordinated atrial activation. On the ECG fibrillatory (f)
waves (rapid oscillations with variable amplitude, shape and timing) replace
normal P waves. Ventricular response becomes irregular and rapid depending of
the intrinsic electrophysiological properties of the AV node1 and the balance between vagal and sympathetic
tone1.
The presence of an irregularly pulse is a clinical sign that can be
quickly and reliably identified in any healthcare situation and, indicates AF with
a high sensitivity and specificity (95% and 75%, respectively). If the
irregularity last for more than 20 seconds the specificity reaches 98% 2-4. Identification of AF can be done by using
manual pulse palpation in those presenting with a variety of symptoms. It is
desirable to check the blood pressure and pulse in all patients who present
with breathlessness, dyspnea, palpitations, syncope, dizziness or chest
discomfort. Furthermore, many patients presenting with an acute stroke are
found to be in AF albeit asymptomatic with respect to non-neurologic
complaints.
The finding of a sustained irregular wide QRS complex tachycardia may be
suspicious of AF conducted with bundle brunch aberrancy or over an accessory pathway,
and in patients with A-V sequential pacemakers can reflect an inadequate
configuration with ventricular tracking of sensed atrial activity.
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