|
medpundit |
||
 |
 |
|
Thursday, December 05, 2002Atrial fibrillation is a very common rhythm disturbance of the heart. Normally, the heart contracts synchronously - the top chambers contract, forcing blood into the bottom chambers, then the bottom chambers contract, forcing it out to the body. In atrial fib, that synchronicity is lost. The top chambers get mixed electrical signals that confuse their muscle fibers and make them contract rapidly, again and again, without regard for what’s happening in the lower chambers. (The “atrial fibrillation” link in the first sentence has a great animated illustration of this.) The problem is, that kind of confused and uncoordinated muscle contraction isn’t very effecient for pumping blood. People with atrial fib often feel their heart racing, they can get light-headed and dizzy, and the blood can pool in areas of the upper chambers of the heart and form clots that could find their way to the brain eventually, resulting in strokes. Current therapy often focuses on using drugs or electric shocks to try to fix the confused signal. Unfortunately, it’s rarely a permanent fix. After being shocked, the heart often reverts back to its confused rhythm, and the drugs we use have all sorts of potential side effects. The good news about today’s studies is that the more pharmacologically benign approach of just slowing the heart rate down is just as good for patients as trying to change the rhythm. The first study found that death rates from atrial fib were just about the same, but a little better for the people who just had their heart rates slowed down (21% vs. 24% mortality). The second, smaller study, looked at the incidence of death as well as strokes, medication side effects, and heart failure between the two approaches. Seventeen percent of the rate-control group had one of those events, compared to 23% in the conversion group. That’s not a huge difference, but it’s enough to demonstrate that the less noxious drugs are the better choice for atrial fib. That’s actually good news for patients. The most commonly used rhythm-converting drug in our area is amiodarone, which requires careful monitoring of liver enzymes, thyroid function, and blood counts. I hate it; especially since the cardiologists around here put the patients on it then expect the primary care physicians to monitor and handle the side effects. They’re then reluctant to take someone off of it when the side effects pop up, because they aren’t the ones dealing with them. (So he’s a little hypothyroid? Put him on some thyroid medication. Can’t have him going back into atrial fib, you know. So he’s having a little vision trouble. His heart’s more important than his eyes.) Now, hopefully they’ll change their approach. posted by Sydney on 12/05/2002 06:45:00 AM 0 comments 0 Comments: |
|
