Device Acts As Heart's Security System

A group of patients is testing a first-of-its-kind implantable monitor that transmits critical data from their heart over the telephone, eliminating travel to the doctor’s office for the same type of monitoring.

Proven successful, the experimental device could herald a major breakthrough for the growing number of people diagnosed with heart failure. Those living with heart failure could enjoy an improved lifestyle with less dependency on frequent doctor visits, and for cardiac researchers it might be the most advanced bellwether device yet for detecting heart problems at their earliest stages.

Within minutes of viewing the transmitted data from any location with computer access, the physician, if needed, can make adjustments to the patients’ medication or prescribe additional therapy.

“I’ve been very impressed with the technology, and patients in the study seem to like it as well,” said Dr. William Abraham, director of cardiology at the OSU Heart Center and principal investigator of the study at Ohio State.

“Instead of seeing a cardiologist about once every two to three weeks for follow-up care, patients with the monitor need an office appointment less than once a month,” said Abraham.

But patient convenience is not the biggest benefit the device has to offer. Data from the monitor often can indicate serious cardiac events are on the horizon days before actual physical symptoms occur. “As a sentinel device, it’s proven to be very effective,” said Abraham. “It’s giving us a head start on treating problems that often would not show up until after a visit to the hospital and invasive testing.”

The Chronicle Implantable Hemodynamic Monitor is about the size of a folded matchbook and is implanted in the upper chest. A sensor attached to the monitor is threaded through a vein into the heart’s right ventricle, where it measures heart rate, heart temperature and blood pressure inside the heart.

Patients pass a magnetic “wand” over their chest to send a signal to the device to transmit data to a doctor via a telephone hookup. Some pacemakers use the same type of technology to relay data, but the information is limited mostly to the condition of the pacemaker and its battery.

One patient in the Ohio State study lives about one and one-half hours away from Columbus. “She is doing extraordinarily well with the device and has a renewed quality of life due to our ability to use the transmitted data to ‘fine tune’ her heart function,” said Abraham. Before the woman received the implant she required continuous oxygen therapy and a wheelchair for mobility. Today she doesn’t need either. “With access to data from the implanted monitor around the clock, 365 days a year, we can be way out ahead of any serious heart problems that might develop,” Abraham said. “If we do see something in the data that we can’t correct with an adjustment in medication or other adjunct therapy, we can ask the patient to come in for further testing.”

Abraham also said the device helps patients avoid unnecessary trips to the emergency department. “People living with heart failure are conditioned to think ‘heart problem’ whenever they feel ill,” he said. “A quick look at the data transmitted from the monitor often is all that is needed to rule out a serious problem in the heart and save the patient some anguish and perhaps an unnecessary trip to the hospital.”

The device, made by Medtronic, has not been approved for general use. However, data accumulated by researchers at Ohio State and other test sites could lead to Food and Drug Administration approval of the device in the next two to three years. At least 50 people are being enrolled in the Ohio State arm of the study.

Almost 5 million Americans suffer from heart failure, and it is the most common cause of hospitalization for older people. Because a failing heart can’t pump efficiently, blood circulation is impaired, causing shortness of breath, fluid in the lungs and swelling in the legs.