New tools for the heart

In the old days,Elzo,73,who lives outside Tulsa,Oklahoma,could have gone for months before the problem was discovered at a routine office visit.

She now has a new defibrillator that communicates directly with her doctor,sending signals about its functions and setting off alarms if things go wrong.

On the horizon is an even smarter heart device that detects deterioration in various heart functions and tells the patient how to adjust medications.

They are part of a new wave of smart implantable devices that is transforming the care of people with heart disease. The hope is that the devices,now being tested in clinical trials,will save lives,reduce medical expenses and nudge heart patients toward managing their symptoms the way people with diabetes manage theirs. Frail patients or those living far from their doctors can be spared frequent office visits. Doctors can learn immediately if devices are malfunctioning or if patients hearts are starting to fail.

The big leap came a few years ago when device companies figured out how to make transmitters that send data over a broader range,20 or 30 feet.

The downside? Information overload is a serious problem for the doctors,said Lynne Warner Stevenson,director of the Heart Failure Program at Brigham and Womens Hospital in Boston and a professor at Harvard Medical School,a proponent of smart devices.

The devices transmit useful data along with data whose significance is not clear,like variations in heart rate. Large swings in heart rate can indicate risk,but it is not clear what to do about them.

Even more confusing are changes in thoracic impedance,a measurement of resistance to electric current through the lung. Impedance changes can predict heart crises,but often have no clinical explanation. Yet when doctors get data on impedance changes,they often feel uneasy and check on patients making them uneasy in turn,Stevenson said.

Richard Page,president of the Heart Rhythm Society,said doctors wonder if they can be held liable for not looking at all the data. Still,he said,the new technology is potentially transformative.