Atrial fibrillation on the monitor

Atrial fibrillation is recognized on the monitor as a ventricular rhythm that is irregular with no pattern to its irregularity, with no discernible P waves in front of a QRS that stays narrow and a baseline that quivers with fibrillatory waves, and it matters for two reasons that the nurse assesses at once in the patient rather than on the strip — the atria that no longer contract let blood stagnate and clot, so the rhythm is above all a stroke risk that is judged and anticoagulated by the patient's own stroke-risk factors and not by how often the rhythm appears or whether it has since converted, and the lost atrial contribution together with a rapid ventricular response can drop the cardiac output, so a patient who is hypotensive, ischemic, confused or in failure because of the rhythm is escalated for synchronized cardioversion rather than slowed with drugs, while the stable patient has the apical rate counted directly because the radial pulse undercounts it, the rate controlled, and any elective restoration of rhythm held until it is known the atria carry no clot.