Special Features + Font Resize -

New breakthrough in pacemaker technology
Dr Vanita Arora | Thursday, November 17, 2011, 08:00 Hrs  [IST]

We are all born with a natural pacemaker that directs our heart to beat sixty to hundred times a minute at rest. The pacemaker is a little mass of muscle fibres the size and shape of an almond known medically as the sino-atrial node located in the right upper chamber of the heart. The natural pacemaker can last a lifetime. Or it can become defective and degenerate with age. And even if it keeps working normally, some point may not function well along the electrical pathway from the pacemaker to the heart’s lower chamber which contracts to force blood out to the body.

Millions of people in the world whose heart beats too slow, too fast or out of sync because their own pacemaker is not able to do the job right, follow their doctor’s 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, 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 hours and 7 days or only when required as per the demand of patient’s body.

Placing a pacemaker requires minor surgery. The surgery usually is done in a hospital or special heart treatment lab. Before the surgery, an intravenous (IV) line will be inserted into one of the patient's veins. The medicine will be given through the IV line to help patient relax.  

Once implanted with a pacemaker there is no problem being around the microwave or computer and while talking on a mobile phone (it is to be held on the side opposite of the pacemaker). But it is best not to walk through airport security scanners, and instead submit to a body search and hand-held scanner.

The biggest "NO" that accompanies the pacemaker is to avoid any magnetic resonance imaging (MRI) examination. This may not seem like a problem at the time one agrees to get a pacemaker implanted. But we never know what turn our health may take. And there are many conditions for which doctors seek to learn more through an MRI scan that uses a very strong magnet, radio frequencies and a computer to produce images of soft tissue, bone and blood vessels. As it produces such detailed images of soft tissue, it is frequently used for organs of the body such as liver, bowel, pancreas, kidneys, brain and spinal cord.
 
Conventional pacemakers
The conventional pacemakers are deemed unsafe by the US Food and Drug Administration for use in magnetic resonance scanners. The wire leads are insulated except for the exposed metal tips that screw into the heart and under the tremendous vibration of an MRI scanner, the tips can heat up to 80°C and can burn the flesh. In addition to hot leads, concerns about implantable devices have centered on the potential of magnetic resonance imaging to inhibit the function of the device and to induce rapid pacing, mechanical pull, rotation of the device, and device failure or reprogramming. There have been a few reported deaths of pacemaker patients who got an MRI and the risk includes movement of the pacemaker and re-setting of the beating pattern. Roughly 50 per cent of patients with a defibrillator or pacemaker will need an MR scan during the lifetime of their device. It turns out that in the population of patients who are over 65 years old, where most of the pacemakers are implanted, the chances of having an indication for MRI doubles.

Focusing on this very important clinical scenario, Medtronic has spent 12 years conducting extensive research and rigorous testing to design a breakthrough pacing system for both pacemaker and lead, so that when used together they allow pacemaker patients to safely undergo magnetic resonance imaging scans. Safety is confirmed only through rigorous scientific testing, clinical studies, and regulatory review. The series is named SureScan. Pacing Systems. They are the world's only pacing systems designed, tested, and approved for magnetic resonance imaging. They are safe by design, not by chance.

Medtronic worldwide has launched this magnetic resonance imaging compatible pacemaker series. This particular magnetic resonance imaging pacing system is the first permanent pacing system to receive the US Food and Drug Administration approval for the magnetic resonance imaging environment.

The magnetic resonance imaging-pacemaker is for new heart patients. Patients who already have a pacemaker can not get this new model unless their old pacemaker and leads are completely removed.

(The author is senior consultant cardiologist, Max Super Specialty Hospital)

Post Your Comment

 

Enquiry Form