Another form of tachycardia that is frequently seen in the pre-hospital and in hospital settings is atrial fibrillation. This is when there is no organised electrical activity in the atria and to look at, the atria is actually at a standstill. Now, we must remember that blood will travel through from the atria into the ventricles without the actual atria contracting.
Approximately 70% of the blood will flow through the atrioventricular valves under pressure. This creates a problem, as approximately 30% of the blood remains in the fibrillating atria and it has a risk of beginning to clot. But as blood flows through normally from the atria to the ventricle, occasionally clots will be dragged through, these will then pass out though the aorta and often travel up the carotid arteries and into the brain, causing CVA or stroke. This puts the patient at a very high risk of stroke and ongoing therapy for this, initiated in hospital settings, would include things like calcium channel blockers, diltiazem is an example, and may also include beta blockers to control the rate and also anticoagulant therapies to prevent CVA.