Telecardiology has been here for a long time. Telephones, and modifications of telephones, have been conceived of¹ and used² for auscultating heart and breath sounds for over 70 years. More sophisticated techniques for transmitting heart sounds more accurately have been used since the 1960’s.^3,4,5 FAXes are used for transmitting EKGs, and EKG tracings (rhythm strips and 12-lead) can be transmitted easily over phone lines. However, not until the past 10 years has the technology been available for doing echocardiograms -- often the gold standard test for diagnosis -- over a distance.

Meanwhile, for most telemedicine systems, cardiology is one of the most requested applications. It is an area of medical care that is particularly anxiety-inducing for many rural practitioners, who greatly appreciate expert backup for those newborns with oddball murmers, and those late-night E.R. visits.

This issue takes a close look at five programs around North America doing tele-echocardiography. One program is doing this along with a full interactive history and physical, including tele-stethoscopy. We’ve chosen these programs because they represent different strategies for delivering cardiac care (see Table). Two are store-and-forward systems, three are real time. One is broadband, one ISDN, one fractional T1, two use standard phone lines. Each one of these programs has taken a critical look at the important issue of efficacy -- of whether in fact the telecardiology technology can reliably transmit the information needed to make good clinical decisions. A few of the programs have also looked (more or less formally) at costs and benefits. The strong consensus is that tele-echocardiography, both real time and store-and-forward, and telestethoscopy are effective ways of transmitting diagnostic-quality information. There is an emerging body of data that suggests they are quite cost-effective, as well. Currently only real-time tele-echocardiography is reliably reimbursed; this may change as efficacy studies of the store-and-forward options accumulate.

There are other telecardiology options. In the New Products section we take a look at a good number of transtelephonic monitoring systems for home health and remote office use.

Finally, Telemedicine Today reviewed 10 electronic stethoscopes, both analog and digital, in our recent Buyer’s Guide and Directory. We compared these in a matrix with over 20 criteria, covering capabilities and prices. Call 800-386-8632 to order a copy; free to subscribers.

1. Frederick HA, Dodge HF. "The stethophone," an electrical stethoscope. Bell Syst Techn J Oct 1924:5310549
2. Vaules DW. Auscultation by telephone (letter). N Eng. J Med 283:880-881, 1970
3. Murphy RLH, Block P, Bird KT, Yurchak P. Accuracy of cardiac auscultation by microwave. Chest 63:578-581, 1973
4. Hasin Y, David S, Rogel S. Transtelephonic adjustment of antiarrhythmic therapy in ambulatory patients. Cardiology 63:243-51, 1978
5. Ducasse R. The value of transtelephonic cardiac monitoring in home health care. The Gerontologist, 28:414-417, 1988

RT=real time; S&F=store-and-forward; ISDN=Integrated Switched Digital Network (dial-up; becoming more commonly available); POTS=Plain Old Telephone System (standard analog phone lines); T1=leased, digital service (not dial-up); Kbps=kilobits per second; Mbps=megabits per second