When I talk to my patient with newly diagnosed atrial fibrillation (AF), after describing the disease and its consequences, there are two major discussions I go through.
The first involves the fact that AF increases the risk of clots forming in the heart and subsequently going to the brain to cause stroke.
The second involves whether we should try to keep the patient from going into atrial fibrillation or, if they are in it continuously, whether we should try to convert them back to the normal (sinus) rhythm.
If this is the first time the patient has had the AF, these are pretty complicated concepts to absorb and difficult decisions to make .
AF Stroke Risk
When the heart goes into AF the left upper chamber or left atrium immediately stops pumping blood in an organized and synchronized fashion.
As a result, blood tends to stagnate in the left atrium and clots can form. A clot in the left atrium can be dislodged and then it travels out the aorta and can land in the brain (causing a stroke) or other vital organs. To see a video on this process and for additional discussion see my post here
Several factors increase the risk of stroke in patients with AF: older age, diabetes, heart failure, and prior stroke or TIA. Based on large population studies we can assess that risk fairly well.
Multiple well done studies have demonstrated that blood thinners such as warfarin or four newer agents will reduce that risk by up to 70%.
If your risk is over 2-3%/ year for stroke, the benefits of stroke reduction outweigh the risk of bleeding that all blood thinners possess.
The first decision an AF patient has to make is:” Should I take a blood thinner?”
(This decision has actually gotten more complicated since the FDA in March 2015 approved a catheter based device which occludes the left atrial appendage and reduces clots/strokes without blood thinners)
Maintaining The Normal Rhythm
Some patients with AF are in it persistently and some go in and out of it.
For both kinds of AF patients a decision has to be made about whether the goal is to maintain the normal rhythm (this is termed rhythm control) or not (this is termed rate control).
If the decision is to pursue rhythm control then options for this goal include medications termed antiarrrythmic drugs, catheter-based ablation or surgical approaches.
If the decision is to not maintain NSR, then we look carefully at the heart rate of the patient with AF (which tends to be much higher than normal ) and add medications (rate-controlling medications) to lower it into the normal range.
For both strategies, it is important to be very cognizant of stroke risk and treat accordingly.
The approach taken in any patient depends on age, symptoms associated with the AF, the presence of other diseases that increase the risk of intervening and multiple other factors.
There tends to be a huge variability in how cardiologists approach the decision of rate versus rhythm control.
Patients are well advised to ponder carefully their options, recognize bias in recommendations, and be very aware of the complications of all treatment recommended.
In subsequent posts I’ll explore in more detail each of these treatment options