MRI-Safe Pacemakers Available In U.S. Hospitals Soon: What It Means For Heart Patients
This was the Guest Blog at Scientific American on February 16th, 2011.
New wave of MRI-safe pacemakers set to ship to hospitals
This week Medtronic will begin shipping to hospitals in the United States the first pacemaker approved by the FDA as safe for most MRI scans. For consumers, it is a significant step in what is expected to be a wave of new MRI-compatible implanted cardiac devices.
But this is an example of one technology chasing another and the one being chased, the MRI scanner, is changing and is a step ahead of the new line of pacemakers. The pacemaker approved for U.S. distribution is Medtronic’s first-generation pacemaker with certain limitations, while its second-generation MRI-compatible pacemaker is already in use in Europe where approval for medical devices is not as demanding as it is in the U.S. So let’s check out what this is all about — what it means now for current and future heart patients and where it may be headed.
We are all born with a natural pacemaker that directs our heart to beat 60 to 100 times a minute at rest. The pacemaker is a little mass of muscle fibers the size and shape of an almond known medically as the sinoatrial node located in the right atrium, one of four chambers of the heart. The natural pacemaker can last a lifetime. Or it can become defective. And even if it keeps working normally, some point may not function well along the electrical pathway from the pacemaker to the heart’s ventricles which contract to force blood out to the body.
Millions of people in the world whose hearts beat too fast, too slow, or out of sync because their own pacemaker is not able to do the job right, follow their doctors’ recommendation to get an artificial pacemaker connected to their heart to direct its beating. The battery-run pacemaker in a titanium or titanium alloy case the size of a small cell phone, (why can’t it be the size of an almond?) is implanted in the upper left chest, just under the skin, with one or two insulated wire leads connecting to the heart. It can be programmed to run 24/7 or to only operate when the heart reaches a certain state of irregular beating. Read more »
*This blog post was originally published at HeartSense*
