Implantable devices equipped with networked sensors are able to monitor patients' condition while at home and alert their healthcare professional by phone to any changes in state.
A study in Circulation: Journal of the American Heart Association reports on the real-world performance of systems such as implantable defibrillators compared with their efficacy in laboratory testing.
The units can operate in isolation, shocking the heart to recover from unusual pulse patterns or cardiac arrest - but can also be connected to a telephone line to transmit data back from their onboard sensors.
Information such as any recorded cardiac events, weight changes, blood pressure or fatigue is sent to a website that the relevant physician can access.
Study co-author Dr Leslie A Saxon says: "We need to expand the capabilities of these networks; they are very promising for our patients."
Dr Saxon is chief of cardiovascular medicine at the Keck School of Medicine at the University of Southern California in Los Angeles.
In 2009-10, the Keck School of Medicine says it has over 5,000 graduates practising as physicians in the southern California area.