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 1960s.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. Weve
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 Buyers 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
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
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
Reviewed In This Issue
||Childrens Mem. Hospital
||U. of Louisville
U. of Kansas
|Storer, Schmidt and Assoc. P.A.
Kansas City, KS
||John Finley, M.D.
||Kaliope Berdusis, RDMS
||Walter Sobczyk, M.D.
Leone Mattioli, M.D.
|James Trippi, M.D.
|Type(s) of telecardiology
|RT or S&F
||microwave / cable / fiber
|POTS, wireless (cellular)
||128 to 384 Kbps
||broadcast quality images
can do full patient H & P (incl.
auscultation), review echo, EKG
no phone line needed
||high transmission cost ($100/hr)
||uncertain ISDN availability
||limited "snapshots" of cardiac cycles
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