Part four, continued from stroke in the Atrial Fibrillation Management notes …Surgeons started this idea of treating atrial fibrillation with procedure, and initiated with the James Cox lab at Duke University. It was found that one can isolate the left atrium electrically by creating scar lines. Scar lines are inert, so they don’t let conduction of electrical impulses occur. In doing that, atrial fibrillation was essentially terminated in many patients. The effectiveness of this procedure, if done in its fullness, is high, around 90% with a fairly low mortality, given that this is an open-heart procedure.
There have been other ways as well; not everyone wants to have their chest opened just for atrial fibrillation. They involve probes and other devices made for non-invasive treatment. Many of these are freely available, although the data is somewhat mixed.
In an important landmark study, in 45 patients, atrial fibrillation began around the pulmonary veins. When you have atrial fibrillation, the pulmonary vein first, and causes the left atrium to go into atrial fibrillation. This was proven when these areas were cauterized. Initial success rates were around 80%, but since this was a decade ago, it’s been learned that all four pulmonary veins, that had the ability do this. Some other areas in the heart, in the left atrium particularly, can also cause atrial fibrillation.
How is this procedure done? Catheters have electrodes on them that can measure electrical activity in the heart, which helps doctors target and eliminate trouble sites. Ultrasound shots help in seeing the procedure actually being done. On average, results are fairly decent at around 80%. However, there are still 0.98 deaths per 1000, because it is so invasive.
For atrial fibrillation ablation, the best candidates are symptomatic patients, especially if they have paroxysmal. People with a very large atrium from years of disease may have lower rates of success. Typically, based on current guidelines, the person must have had to have tried a drug prior and failed before being taken to catheter ablation.
At Stanford, a 75-year-old woman with atrial fibrillation despite medications including sotalol, felt very poorly. She had multiple attempts to restore normal rhythm, but she would be in normal rhythm for a week or two but then go back to irregular. Her left atrium was mapped out geometrically. Her normal rhythm was restored using ablation and was able to return to a normal quality of life.
There will be future studies that aim to research even more ways of treating this disease. One is called CABANA, located at Stanford. It will be a randomized study looking at ablation vs. rate control strategy. Drugs may be good in some patients but not others, so with ablation we may be able to achieve normal rhythm and better outcomes; better mortality with less risk.
Medications aren’t introduced every day, so we’re excited about a new medication under the trade name Multaq. It may have a significant role in treating atrial fibrillation. Technologies being developed will have great impact on many patients. Robotic use in catheter ablation has promise and potential.