Rheos: A "Pacemaker" to Lower High Blood Pressure

High blood pressure, or hypertension, is often called the "silent killer", because it usually has no overt symptoms. One can have high blood pressure and not know it unless it is taken with a blood pressure meter. High blood pressure can lead to a variety of diseases, including strokes, heart attacks, and kidney failure. Some sixty five million Americans have high blood pressure.

High blood pressure is most often controlled by medication. A daily regime of medication, prescribed by a physician, can lower blood pressure to a safe level. Also, diet and exercise can lower blood pressure, particularly if the hypertension is caused by being overweight.

A few people do not respond to blood pressure medication. Hitherto, such people live at greater risk for severe health problems and even death. But now a medical device is undergoing Phase 2 human trials that could eventually save these people's lives and allow them to live normally.

The device, called the Rheos Baroreflex Hypertension Therapy System, developed by CVRx Inc, promises to be for regulating blood pressure what the pacemaker is for regulating heart rhythm. It is an ipod sized device that is implanted at the carotid artery. Tiny wires interact with nerves in the artery and quite literally orders the brain to bring down the body's blood pressure. When activated by the Rheos system, signals are sent to the central nervous system and interpreted as a rise in blood pressure. The brain works to counteract this perceived rise by dilating blood vessels to allow blood to flow more freely, reducing the heart rate and influencing the kidneys to release fluid.

The device has already undergone limited trials in Europe and has met with some success with patients with severe hypertension. The first American to receive the implant was a woman in Rochester, New York in April, 2005. Her systolic BP dropped from 210 to about 160 because of the device.

About a dozen or so more patients will have received the device during the Phase Two trials. Medical researchers will want to monitor these patients for about two years before going to wider, nation wide human trials.

If the Rheos device is successfully tested and approved for commercial sale, it could revolutionize the way hypertension is treated. Certainly it will be a boon to those people whose high blood pressure does not respond to medication or lifestyle changes. Eventually, the Rheos implant might actually replace medication in many patients, relieving them of having to undertake a medication regime.