SE
Draft: January 26, 1972

REGIONAL MEDICAL PROGRAMS SERVICE
AND

COMPUTER ASSISTED EKG ANALYSIS SYSTEMS

Division of Professional and
Technical Development
‘Regional Medical Programs Service
I.

II,
4a.
“Iv.
v.
“VI.
yi,

VIII.

. IX °

TABLE OF CONTENTS

Introduction

Need for Improved Electrocardiographic Services
Description of CAE Systems — |

Current Functional Status of CAE Systems

Advantages and Potential Advantages of CAE Systems

‘Limitations

Potential RMPS Roles

Deployment
Recommendations

"Appendix I
I. Introduction

The staff report of August 1971 entitled "Computer Assisted EKG
Analysis and the Regional Medical Programs" described the difficulties
encountered by four Regional Medical Programs in the development and
implementation of a computer assisted electrocardiographic system (CAE).
The information presented was obtained from review of appropriate
materials contained in grant applications, correspondence files, site
visit and progress reports, Statements pertaining to the functional
capabilities of established CAE systems were derived from a limited
review of pertinent literature, and attempted to define the practical
advantages and the inadequacies of existing systems. The limitations
inherent to a report based solely upon these sources are apparent. _
Accordingly, the report was submitted to experts in the field of a
» puterized electrocardiography both within and without RMPS with the
purpose of identifying major deficiencies and inaccuracies contained
in it, and to offer appropriate suggestions. Additionally, an ad hoc
panel of experts was convened by RMPS to discuss the veport. and to
apprise RMPS as to the current state of the art. A list of participants

at this meeting, and the agenda is included in Appendix I.

The present report has been prepared: in direct response to the
‘reactions. generated by the initial paper and reflects the continued
interest on the part of both the Regional Medical Programe Service ~
and individual Regional Medical Programs with respect to CAE systems.

‘Three sources of information have been utilized:
2,

1, Background and descriptive material derived from the current |
medical literature included in the annotated bibliography accompanying

this report. (Appendix II)

2. Written communicatigns from the project directors of four

ongoing RMP supported CAE programs.

3, The stenographic transcript of the proceeding of the ad hoc

advisory panel assembled by BMPS on November 30, 1971. ._
The objectives of this report include the following:

“1. To summarize the present functional capabilities of CAE
systems with emphasis directed towards practical potentials and

applications, and realistic limitations.

2. To establish suitable roles for RMPS with respect to design,

development and implementation of CAE systems,

3. ‘Yo provide guidelines with respect to system selection,
deployment and marketing strategies for use by RMPs interested in

CAL systems, ;

 

 
3.
4. To provide suitable information for use by the National

Advisory Council, RMPS, in establishing policy with respect to sup-

port of CAE systems.
5. To recommend appropriate RMPS policy in this area.

Il. Need for Improved Electrocardiographic Services

Disorders of the cardiovascular system are the leading causes of
morbidity and mortality in the United States. It has been estimated
that. over one million Americans die from acute coronary heart disease
annually, and an additional several hundred thousand succumb to cerebro-.
vascular diseases. — The electrocardiogram is an essential tool in the
evaluation and management of these and other disorders. It is ac-
knowledged ‘by experts, however, that many areas of the country lack
adequate electrocardiographic services. The average practitioner,

though often familiar with. the rudiments of EKG interpretation, relies

| upon the assistance of associates more thoroughly trained in this

specialized area. Ideally, an expert cardiologist should be available
for this service, but this is frequently not the case. More commonly, an
interntet or ‘general practitioner with an interest in electrocardiog-
raphy assumes this function. Clearly, the quality of electrocardio-
graphic services available in any particular area of the country may.

be. quite variable. Many potential solutions to this problem exist.

» Training more cardiologists or additional training for. non-

cardiologist physicians are two approaches. It must be realized, _
however, that the existing deficiencies are as much due to mal--
distribution of trained personnel as they are to inadequacies in
absolute numbers. It is all too common to find an abundance of
highly trained cardiologists concentrated around a sophisticated
medical center while the surrounding “community lacks such expertise.
The problem is even more obvious when one examines the services
available to peripheral community hospitals in the more rural areas
of the country. It is unrealistic to expect more equitable distri-
bution of existing manpower in the near future. The extension of
expert services available in modern medical centers into their
surrounding regions through application of advanced technology is an
attractive alternative. Computer assisted EKG systems represents

one example of this: approach.

‘Aside from the necessity of increasing the availability. of EKG
“services, there exists a need to improve the quality of EKG inter-
pretation. Conventional electrocardiography suffers from several
shortcomings basic to which are the limitations of the human mind.
Even the most skilled cardiologist is subject to fatigue. This
affects both his observations and his analysis. Lack of consistency
in the application of the multiplicity of diagnostic criteria is
another characteristic that impairs the performance of electrocardi-
ographers. Finally, human EKG interpretation is biased by factors

other a the analytic data provided in the tracings. The electro-

 

 

_eardtographer has variable access to information regarding the patient's

ages aex, health status, nedication, syuptomatology, etc., and this

 
e .

influences his estimation of various abnormalities of EKG waveform.
Though such clinical correlation is essential to accurate patient
evaluation, it distorts the interpretation of objective data presented
in the EKG. All of these factors contribute to the variability of
human EKG interpretation. This is reflected in the magnitude of
disagreement found among experts analyzing the same EKG, and in the
inconsistencies detected when the one interpreter reads the same
tracing on different occasions. Skilled electrocardiographers exhibit
a reproducibility of EKG diagnosis of approximately 80%; the perform- |
ance of non-experts is more variable, The digital computer is well |
suited to EKG analysis, and, as will be subsequently discussed, is
6 capable of overcoming many of the limitations inherent to human

interpretation.

Any proposed system designed to improve the availability and
quality of electrocardiographic services must do - within the re-
straints imposed by existing economic resourcés. The cost of a con-
ventional EKG varies considerably throughout the country from a few
dollare to thirty dollars or more. These figures represent the fee -
charged by the provider institution or physician and do not necessarily
reflect the true cost of the unit cardiogram. Limited data are avail-
able analyzing component costs, i.e., technician salaries, software,
maintenance, and overhead. One important objective for any EKG
service including CAE eyetems must be cost-containment. ‘Additional

©} hardware, software and personnel, costs should not add significantly
6.

 

to existing expenditures. The service must be provided at comparable —

costs, or preferably, with cost savings.

III. Description of CAE Systems

The digital computer is capable of analyzing large volumes of
specific electrocardiographic variables related to wave contour,
Magnitude, duration, and frequency. The recognition of deviations
from programmed normal, velues in these parameters permits discrimination
of abnormal EKGs from normal ones. Identification of patterns of |
deviation can then be translated into specific diagnostic statements.

The computer, therefore, may serve only to select out abnormal tracings

 

from a larger population of normal ones. Or, the computer may offer

diagnostic interpretations with appropriate alternatives and exclusions.

Though individual systems differ with respect to specific hard-

ware, they all share some common features:

1. A device to detect and record the electrical events of the

heart and a preamplifier system to amplify the millivolt-range

physiologic signals to a level that can be worked with conveniently

(data acquisition cart).

2. A system for converting this signal into a mode suitable

for computer input (analog-digital conversion).

3. A means of storing and transmitting the coded signal to

 

the digital computer. ©
© 7,
4. A digital computer and a suitable computer program

Available systems differ with respect to design of acquisition
carts (single channel versus three channel), input mode, computer
facilities, and printout equipment. The recording technique includes
either standard twelve lead tracings, Frank orthogonal leads, or com-
binations of these leads. Several contour and rhythm programs are
available, most using concepts of binary logic. The use of multi-
variate statistical analysis remains largely developmental. Differ-
ences also exist in the form of the computer printout (paper and
microfilm), mounting, storage and retrieval capabilities. Finally,

@ the types of service provided by any single system vary.

Recognizing the multiplicity of CAE systems currently in
operation, and the variety of hardware, software, program and logis-
tics involved, the succeeding section concerned with current functional
capabilities of CAE systems will confine itself to general issues and

avoid detailed analysis of any single system.

IV, Current Functional Status of CAE Systems

A. Range of Services

Screening: Large volumes of EKGs can be batch processed by
existing CAE systems. rapidly, reliably, and at reasonable cost.
| @ Patients with abnormal or borderline tracings may be selected out by

the computer for further evaluation. - In addition to separating normal
from abnormal EKGs, the computer may provide specific diagnostic ©

statements. EKGs determined to be normal by the computer appear to
require no further validation, since the incidence of false negative
interpretations is less than 1%. Depending upon the rigidity of the
. diagnostic criteria, the incidence of false positive diagnosis may |
be as high as 20%; therefore tracings with suspected abnormalities —

require physician validation.

Definitive Interpretation: The succeeding sections
dealing with the accuracy, volume capacity and cost factors of CAE.
systema relate: primarily to those. systems providing definitive inter-
pretation. Some general comments are in order at this point. Several
EKG wave contour and rhythm programs are currently available, and have
met with varying success. Most offer standard twelve lead tracings
along .with vectorcardiographic display. Increased utilization of:
the vectorcardiogram (VCG) should be considered advantageous, since
it provides the electrocardiographer with additional useful information.
CAE systems have proven to be quite flexible in that changing diag-
nostic criteria can be accommodated for by appropriate alterations

in programming.

CAE systems have also shown flexibility with respect to.
deployment. Computer centers have provided EKG services in a variety
of enviconments including large medical complexes, small and medium
sized hospitals, outpatient clinics, email group practices and solo

office practices.

 

 

 
Multiple sources of funding have provided the necessary ;
working capital including NCHSR&D, RMPS, commercial interests and
institutional research and development grants. CAE systems are
presently available both from commercial enterprises and from several

large medical centers.

Critical Care Unit Monitoring: On-line EKG monitoring in

coronary care (CCU), intensive care (ICU), and respiratory care units
may provide continuous surveillance of cardiac rhythm and contour.
Other physiologic variables often simultaneously monitored include
blood gases, blood pressure, respiratory rate and temperature. Inade-
quacies of human senses with respect to continuous observation of
multiple. variables have been well documented. The application of CAE

systems in these environments is largely developmental.

‘Exercise Testing: Several programs have been designed for
continuous analysis of EKG wave contour and rhythm during graded exer-
cise testing. These programs are essentially research oriented. Com-
puterized analysis of exercise testing is not widely available, and

must be considered in a dovelommentat stage.

‘Comparative Interpretation: Though several computer a
grams are undergoing developnent, relatively few CAE systems provide
for even limited comparative EKG interpretation. Improved technology
is available for expansion of storage and retrieval capabilities which

may be expected to. facilitate comparative analysis. Disagreement.
10.

exists, however, as ‘to which Parameters should ‘be compared. Addition-
ally, it has been stated by some experts that comparative EKG analysis
can be performed more effectively by human observers. All agree that
comparative evaluation of multiple EKGs adds valuable information to
patient assessuent, and further development of this aspect of CAE

systems is to be expected.

B. Accuracy

Computer analysis of EKGs may be subdivided into three dis-
tinct processes: signal acquisition and measurement, comparison of
determined parameters against sets of normal values, and synthesis

of patterns of deviation from normal values into diagnostic statements.

With respect to the feaeurement process, the computer appears
capable of precision comparable to the most meticulous human effort.
Though some variation in wave measurement is inherent to the sampling
procedure, it is minimal. The computer experiences difficulties in
areas similarly eroubLesoue to human observers, i.e., P wave recog-
nition, detection of minute r ‘waves, and determination of initiation,
duration and termination of Q waves, ST segment and T wave. Unlike
their human counterparts, computers are not subject to fatigue, thus

assuring consistency of repetitive determinations.

Recognition of deviations from normal values and synthesis
of diagnostic statements rely upon both the precision of wave measure-

ment and the adequacy of programmed normal values and logic. Computers

 

 

 
11.

offer the distinct advantage of being able to retain large volumes
of information, including the multiple parameters required for EKG
analysis. The major limitations are the validity of the programmed
normal values and diagnostic criteria, and these limitations apply
equally to both computer and human interpretation. Most CAE systems
in current use utilize binary logic and decision tables that attempt
to duplicate the analytic processes of the expert electrocardiographer..
The net effect of the computer interface is enhanced reproducibility
of interpretation resulting from rigid adherence to programmed in-
structions. 1 Errors of omission are minimized, though at the expense

of 10- 20% false positive, statements.

If : accuracy of CAE systems is defined as degree of agreement
with expert human interpretation, then optimal performance. should be
reflected in 100% computer =physician agreement. In practice, less.
than the ideal is realized. Approximate figures from systems serving
large inpatient populations containing a preponderance of abnormal’ *
tracings indicate that 85% of computer. analyzed EKGs ‘require no iubse-
quent alteration or modification, lees, the physician-computer agree-
ment approaches 85%. Greater agreement has been achieved with contour
analysis (approx. 90%),- while rhythm statements are less reliable
(75-80% agreement). oe | |

“Two general reasons for computer-physician disagreement are

identifiable: CAE system error and Physician error. Factors affect-

ing human. performance have previously been. alluded to and include
12.

 

fatigue, forgetfulness, imprecise measurement, inconsistency of diag-
nostic criteria, and bias.. CAE system failure may be separated into

defects in data acquisition, data transmission, and data analysis.

The dominant sources of errors of acquisition are related
to inadequate recording techniques, improper lead. positioning, inad-
vertant omission of leads, respiratory variations, artifact, and back-
ground and transmission noise. “Many of these problems are resolvable
through improved technician training, and modification of the data
acquisition carts. The design of more suitable electrodes and improved
methods for signal filtering are under development, and can be expected

to enhance the quality of the recorded signal. Similarly, distortion,

 

noise, and artifact introduced during telephonic transmission appear

to be potentially solvable technological problems.

Analytic errors may be further categorized into inadequacies
of programming, errors in measurement, and disagreement as to diag-
nostic classification. ‘Errors of measurement relate to the sampling
process and, as previously mentioned, most often involve failure. to
detect P waves and QRS, QT and ST-T segment duration. Artifact, back-
ground noise, and unrecognized ectopic beats may further contribute

to measurement error.

Instances where wave measurement is accurate but diagnostic
classification is improper are usually due to remedial errore in pro-

gramming. Disagreement with respect to diagnostic classification oe

 
13.

often reflects minor discrepancies between computer and electrocardi-
ographer. Physician inconsistency and ambiguity of diagnostic criteria

are most often responsible.

In summary, though the degree of cardiologist-computer agree-
ment ig quite high, a significant incidence of major dicagreement still
exists, thus necessitating human validation of all computer analyzed
EKGs. Except in screening situations in which the computer can be
relied upon to separate normal EKGs from equivocal and abnormal ones
independently, CAE systems serve to assist the electrocardiographer
in his task. The value of the physician-computer interaction will be

discussed ina subsequent ‘section (Vv).

C. Volume Capacity

A decided advantage of CAE systems is their ability to
process large numbers of electrocardiograms rapidly and continuously.
The volume capacity of any CAE system is determined by three major
variables: data acquisition time, computer ‘time, and physician vali-
dation time. Acquisition time is affected by technician skill, number
of leads recorded, and type of cart utilized. Using carts ‘currently
available for recording three leads simultaneously, the acquisition
time for a twelve lead tracing is comparable to recording a standard
twelve lead EKG on a one channel cart. Addition of three Frank
orthogonal leads increases recording time slightly. The quality of

the acquired signal is an important determinant of overall system
14

performance and this is directly influenced by the skill and motivation

of the recording technician, ‘Additional training fs necessary to assure

high quality signal acquisition,

Among the factors controlling computer time are the following: .
capacity of the computer, complexity of computer contour and rhythm
programs, input mode (batch processing versus interrupted input), and
range of services provided. Comparative interpretation requires addi-
tional time to allow for search and retrieval of stored records. A
medium capacity, ‘dedicated computer is capable of processing approxi-~
mately two hundred EKGs ‘per hour including analysis and data printout

without comparative interpretation.

From a clinical standpoint, it igs advantageous to provide the
physician with an interpreted tracing. with minimal delay. The key
determinant of turn-around time, i.e,, time from inscription of the
signal to delivery of the definitive interpretation, is the additional
time required for validation of the computer record. The computer
can provide an interpretation within minutes of the inscription
of the signal. All computer diagnoses, however, excepting those
determined to be entirely normal in screening situation, must be
authenticated by an electrocardiographer. At the present time this
service may be provided by cardiologists associated with the computer
center, local cardiologists, or physicians requesting the electro~
cardiographic service. It is generally agreed that the physician-
utilizer should be provided with a validated record, and that
review by an electrocardiographer is necessary. It is the degree

af aaatatance offered by the CAE syatem to the electrocardiographer

 

 

 
that determines its effective output. Tracings identified as being
normal by the computer require no more than casual verification.
Similarly, many abnormalities are analyzed 80 reliably by the CAE
system that the reviewer can accept these diagnostic statements with
a high level of confidence. Complex contour abnormalities and arrhyth- -
mias require closer scrutiny. The computer interface accelerates
analysis of routine tracings allowing the electrocardiographer more
time to consider the more complicated ones. The interpretation time
of a cardiologist reading predominantly abnormal tracings may be
halved, thus potentially doubling his output. Utilizing batch Pro-
cessing, turn-around time for a computer assisted EKG interpretation

© with verification averages twelve hours or less.

 

D. Cost Factors |

. From the standpoint of the CAE systems provider it is éon-
venient: to examine component costs in three areas: data acquisition
and transmission, computer processing, and physician validation. It
must be emphasized that the figures mentioned are only approximations,
with significant variations existing among individual CAE syutene.

Some of the factors responsible for these differences will be identified.

Aside from the computer, the data acquisition cart is the
single most expensive hardware component of CAE systems. Cost of
@ puichase varies from $6,000 to $10, 000, whereas rental fees average

“$2,000 to $3, 000 yearly. Assuming the functional life of this equip-

ment to be five to seven: years, cost per unit EKG based “upon an annual
volume of two thous:-nd tracings is $1.00 to $2.00. this is eiclusive
of maintenance, overhead, supplies, and technician salaries. Theae a
factors must ‘be figured into the total cost a acquisition, and apply
to both systems utilizing computer analysis, and to conventional EKG
services. Where technicians function solely to record EKGs, the unit
cost is increased by an amount calculated by dividing technician
salary by annual volume of tracings. In institutions generating Large
volumes of EKGs, technician salaries add approximately $2.00 to unit
acquisition costs. Smaller hospitals often use EKG technicians for .

a variety of functions in addition to EKG recording, | thus obscuring

the analysis of acquisition costs.

Computer costs are influenced by computer size, processing
mode, range of service provided, and data display form. The most
important determinant of ‘computer costs is efficiency of utilization.
Maximal utilization in terms of volume of EKGs processed results in.
optimal unit cost. Cost-effectivenesa can be achieved on a medium
sized (e.g., IBM 1800) dedicated computer with an annual volume of
100,000 tracings. Lesser volumes are more economically handled using
a medium sized computer on a time-sharing basis. Uninterrupted batch
processing is the most efficient input mode. Periodic "stat" or
emergency tracings must be anticipated in any system designed to pro-
vide complete electrocardiographic services to inpatient populations,
though these interruptions impair the operating efficiency of CAE
systems. The addition of data storage and retrieval capabilities

necessary for comparative interpretation increases unit cost, as do

 

 

 

 
17.

modifications in the form and content of data display. Estimates of
$1.00 to $3.00 have been made for direct computer costs exclusive of
salaries for programmers, clerks, secretaries, maintenance, and a
head. Representative combined cost per unit EKG including acquisi-
tion, transmission, processing, printout and return varies from $5.00
to $7.50. However, accurate estimates of total direct and indirect

costs ere not available.

Finally, there is the cost of validating the preprocessed
EKG, As already mentioned, the fee charged for a standard electro-
cardiogram shows marked regional variation and the total cost trans-
mitted to the patient is not an accurate reflection of the component
costs of the service, The fees charged by physicians for interpre-_
tation of tracings are highly variable. If the costs of computer
preprocessing are. simply. added to the customary fee charged by the
electrocardiographer, cost containment and reduction are not achieved.
The obvious question remains: How can the benefits of computer assisted
EKG analysis be realized without inflating the cost of the finished

product?

% Most commercial organizations marketing CAE systems essentially
ignore the problem by not including physician validation as part. of
the service they sell, From both medical and legal viewpoints, com-
puter processed electrocardiograms. lacking individual verification
by a skilled electrocardiographer are unacceptable. Whether or not
these companies can provide CAE services with constantly available:

physician validation at competitive prices is uncertain at this time.
18.

Two mechanisms to provide for validation may be offered. The first

is employment by the computer center of electrocardiographers for the
purpose of providing validation. A foreseeable problem is the avail-.
ability of round= the-clock coverage. A second approach is validation
by local cardiologists in the area being served by the computer center.
To avoid increasing EKG costs by addition of computer costs to local
ones, some adjustment of physician fees may become necessary. Theor-
etically, since computer preprocessing is estimated to reduce the ‘time
required for physician interpretation, a reduction in unit cost may

be possible. However , this will depend upon the complexity of the

tracings, the need for comparison and the number of tracings analyzed.

CAE systems situated in university medical center com-.— -
plexes have been able to provide EKG service with validation on a
twenty-four hour a day basis and ‘at a cost of oo $4.50 to $6. 50.
There are several reasons for this. Most important are the investi-
gative aspects of these programs and the interests of the participating
cardiologists. ‘It is obvious that the bulk of the money generated
from the service charge covers. the cost of acquisition and computer
processing; a relatively small fraction goes to the physicians over-
seeing the operation. secondly, several additional sources of funding
are available to these programs including support from private industry,
foundations, and internal research and development monies. Thirdly,
at least some of the supervisory function is assumed by members of
the house staffs, though all tracings are ultimately reviewed by

senior staff members. Fourthly, the current service charges are

 

 

 
e os

adequate for support of the ongoing programs but fail to include
initial developmental and marketing expenses. Lastly, these programs

operate on a large annual volume of tracings.

In summary then, several viable CAE systems are available
that are capable of delivering high quality electrocardiographic
services at reasonable cost. Though current service charges provide
adequate support for established, ongoing systems, they do not com-

pensate for start-up costs which may be considerable.
V. Advantages and Potential Advantages of CAE Systems
A. Quality of Electrocardiographic Services —

. . Computer preprocessing of EKGs minimizes the adverse.
effects of physician fatigue, forgetfulness, and bias. Rigid adherence
to programmed criteria diminishes errors of omission by alerting the
physician to diagnostic possibilities otherwise overlooked. Similarly,
sources of physician misdiagnosis become identifiable upon review of
the analog data presented in the computer printout. The computer “inter-
face allows for greater standarization of diagnostic criteria, thus
reducing inter-observer and intra-observer variation, and enhancing
analytic reproducibility. Additionally, technicians must be more
meticulous during EKG recording to insure optimal signals for computer
input this enhances the quality of the data display and serves a6 a
built-in quality control mechanism. Overall, the quality of the EKG
resulting from the computer-physician interaction is superior to that

furnished by either one separately.

B. Utilization of Manpower
With respect to the EKG technician, utilization of the

data acquisition carts is somewhat more complicated than conventional
electrocardiagraphs,. and additional training is required, This is not
difficult to achieve and technicians readily adapt to the new carts.
Recording tine may be slightly increased when fourteen or fifteen lead

positions are required; though in general, the recording time on -

 

 

 
21

multichannel acquisition carts is comparable to standard machines.

The computer interface permits automation of cutting
and mounting of tracings, thus freeing technicians from these time-
consuming tasks, Similarly, computer processing provides automated
determination of impulse duration, magnitude, direction and frequency,
these tasks having previously been the responsibility of the individual
interpreting the EKG, The net effect is a significant savings in

personnel time.

Two positive effects upon physician utilization are
discernible, Firstly, computer assistance enhances the speed of inter-
pretation of the electrocardiographer, diminishing the amount of time
necessary. for the review of tracings. This is translatable into | an
increased volume capacity. for the physician allowing him to examine
more records in leas time. ‘The time saved can be invested in other
areas demanding his attention. . Secondly, CAE systems serve to expand.
the outreach of the electrocardiographic abilities situated within the
computer ,center. As a result, the general quality of electrocardiography
in the communi ty is improved, and areas lacking the essential manpover
can have access to high quality services, conveniently and at manageable

cost.
C. Regionalization

: “One. attractive aspect of CAE syetens from the point. of

view of RMPS, ta the potential for implementing. planned delivery of
“22

essential nedical services on a regional baste. “this ie particularly
true for thone. systens chased in a medical center environment. ‘The
linkages established between provider institutions and péripheral
medical facilities and-personnel have the potential for developing —
beyond service relationships into viable communications networks. It”
is difficult to estimate the effectiveness and quality of: cooperative

relationships fostered by existing CAE systems.
D. Increased Interest

It is probable that the avet lability of CAE syatens has.
and will. continue to stimulate increased interest ‘in electrocardi ography
among practicing physicians. This interest is expressed as increased»
utilization of the electrocardiogran in patient evaluation in both

hospital and aubulatory care environments, on: a more routine basis.

E. Continuing Education

Tt has also been suggested that the CAE data display is
an effective educational device. ‘Certainly the information contained
in the printout, Lees, analog data, including diagnostic eriterta and
tracing reproduction, can ‘increase the knowledge of the average physician.
However, the extent to which it is utilized is determined by the motivation

of the recipient. An evaluation of the educational aspects of CAE

systems is not available.

 

 

 
o_ | :

F. CAE Systems as a Reference Point

_ As has been mentioned, little information is available
with respect to cost and time factors associated with the recording and
interpretation of conventional electrocardiograms. Similarly, relatively
few studies attempt to define the quality of standard EKGs, The develop-
ment of CAE srogtaes has resulted in increased understanding of these
and other aspects of electrocardiography. This has been evidenced by
material presented earlier in this paper dealing with cost factors,

volume capacity, and sources of physician-computer disagreement.
G. Data Base

@ : Much of our current knowledge of electrocardiography is
based upon analysis of relatively small numbers of tracings. In part,
this accounts for. the multiplicity of diagnostic criteria presently in
uge. It is in this area that computer technology will probably have the
greatest impact. The enormous capacity of computers pemnite analysis and
clini copathologic correlation of hundreds of thousands of electrocardio-
grams, enabling us to more accurately define the limits of normality and
the determinants of abnormality. The application of computer techniques
has already pointed out ‘the limitations of conventional electrocardicgraphy,
and will continue to add new ‘knowledge. Further research in these areas,
ineluding the. application of. analog computers, aultivariate analysis,

and high Erequency electrocardiography can be expected to alter the EKG

@ . of the. future.
24

VI. Limitations

The preceding pages have dealt almost entirely with the
positive aspects of CAE systems. Unresolved problems do exist, however,

and need to be identified.
A. Costs
Provider

One persistent problem relates to program start-up. Estab-
lished CAE systems with adequate support, in terms of operating volume, are
able to sustain themselves on funds generated by service charges comparable
to the fees received for conventional EKGs. In other words, a potential |
subscriber can purchase the service from one of several functioning :
systems rather than. relying on local resources without increasing the
cost to his patient. But the funds accumulated by the provider in this
way cover only cost of operation. The money expended during program
initiation, development and growth may not be recovered. The commercial
interest or institution organizing a CAE system must have access to
sufficient capital to cover the costs of start-up. In addition, a period
of time mst be planned for acquisition of an adequate market and over-

. coming technical difficulties. ‘The magnitude of these variables have

not yet been clearly defined.

Maintenance and operating costs will be determined by local, needs,

and by willingness of local physicians and institutions to subscribe. to the

 

 

 
25
service. Several CAE systems have been unsuccessful because of their

inability to establish an adequate market.
Utilizer

Those individuals and institutions interested in subscribing
to a CAE system must first assess their needs and resources. partici~
: pation fin such systems is expensive. Total direct and indirect costs
have not yet been clearly delineated, At the present time, verification
by an experienced electrocardiographer must be .included in any CAE
system. The potential cost benefits derived from the system must be
analyzed to separate data acquisition aavings, from the savings derived —
by ‘reduction in the time required for EKG interpretation. The former
is applicable to all EKG systems. The cost to a physician’ s office, or
a small EKG laboratory must be evaluated against the costs of alternative
EKG interpretation systems. Though CAE systems utilization may be the
most advantageous arrangement in certain situations, other approaches
exist, and should be considered when planning for improvement of

electrocardiographic services.
Be Performance

| Because of the rapid development of computer technology during
the past decade, CAE systems should be considered to be ina transitional

phase with respect. ‘to! ‘capabilities and range of services. Disageeenent
 

26

among experts as to what constitutes optimal system components, both
hardware and software, continues. Further refinements of data acquisition |
carts, rhythm and comparative programs, storage and retrieval capabilities
are to be expected. Increased interest in alternative approaches, such

as multivariate statistical analysis and increased usage of analog
computers, will alter the nature of CAE systems of the future. How

rapidly these changes will occux is difficult to predict.

Whether or not a completely automated EKG system is achievable is
also debated. Artifacts, complex arrhythmias, minute inconstant deflections,
the need for comparative interpretation, and transmission difficulties

are all challenges to this goal. The advantages anticipated with utilizing

 

a CAE system to provide physician assistance must be evaluated against the
adequacy of existing services in the region or institution. Emphasis
should be directed towards’ the delivery of high quality electrocardio-
graphy by physicians and institutions lacking this service to their
patients. Of the various benefits described in section V, the most
important, from the viewpoint of RMPS, is the potential for extending
the outreach of the expertise within the computer center into the
surrounding community . The development of a CAE system to serve a
single large medical center complex, without linkage to surrounding
institutions, is of lower priority. Though the quality of electro-
cardtography as practiced in these centers may be enhanced by the

computer interface, such deployment would have little influence upon

 

the EKG resources of the surrounding region, where the need is more

apparent.
27

Related to this, though on a more philosophical level, are the
inherent limitations of the most popular CAE systems; i.e., those pro-
grammed to reproduce human decision-making and logic, Designed to mimic,
the expert electrocardiographer, such systems assume the limitations of
conventional electrocardiography, Some have suggested that greater
benefit would be derived by employing computers to do what the human mind

cannot do == to examine parameters and variables ignored in currect practice,

VII. Potential RMPS Roles

In direct response to the question posed by RMPS, members of the
ad hoc panel suggested several possible roles for involvement of
individual RMPs with CAE systems. The following suggestions reflect
the opinions of the panel members and are not necessarily in agreement with

RMPS goals and policies, They are presented for information only.

A. Informationt
1. Assist in the evaluation of local and “regional EKG

resources and needs,

2 Identify appropriate methods for fulfilling such needs.

By Edug ation:

1 Serve as a source of information concerning the availability,

capabilities, and potential advantages of CAE systems,

2, ‘Inform local physicians and institutions as to the existence

of this type of EKG service. »

Be: Encourage participation in such systems where local need is
 

demonstrated,

4, Assist in overcoming local resistence to implementatton
of CAE systems, . |

5. Provide similar information with respect to alternative

approaches for the delivery of EKG service.

C. Organization:

1, Encourage communication between the health care providers
and health institutions of the region so that common needs may be

recognized.

 

2, Foster cooperative arrangements among local hospitals with
the aim of improving the quality and availability of EKG services, whether

utilizing CAE systems or some alternative.

D. Consultation:
1. Provide technical and organizational assistance to physicians
and institutions interested in subscribing to or initiating a CAE systen,
26 Serve as liaison between interested parties and experts in
the field of computer assisted electrocardiography.

3. Provide similar consultative assistance to those interested

in alternative EKG service system,

E. - Support:
1. Make available limited monetary support to assist in tie

 

planning and implementation of regional EKG services including CAE systems.

2. Provide short term assistance until these systems become
@ .

self~supporting.

F. Research and Development

1. Encourage essential investigative work in areas related to
CAE systems —— @.8+, exercise testing prograns, coronary care unit
surveillance, etc.

2. Encourage and support projects concerned with the extension

of advanced technology into the special care unit environment,

VIILI Deplovment
A. . Computer Facilities ‘

© | Both commercial and institutional computer centers have been
utilized. Private industry has played a large role in the development and
implementation of reliable CAE systems. Since they have proved successful,
and because they can operate on a profit making basis, it is most appro-
priate that CAE systems be marketed by commercial organizations. Ongoing
research and development are essential in all.viable industries, CAE |
systems being no exception. Continued development of system hardware. and

software should properly remain the responsibility of private industry. .

The use , of conputer facilities within the medical center environ=
ment offers additional advantages including a proximity to expert ‘electro=

cardiographer, educational potential, availability for EKG research, and

© ‘the possibility for establishment of a regional communications network.
30
The availability of both equipment and personnel, and the capacity for

sharing computer time and programmer time are also attractive aspects of

an institutional computer base.
B. Data Acquisition Terminals ~

A variety of sites for deployment of computer terminals have
been explored. Most often, mobile data acquisition carts have been
utilized. Efficiency is enhanced in situations where the carts are
stationary and patients are required to come to some area set aside for
the recording of EKGs. This is, however, impractical in many cireum-
atances. Small and medium sized hospitals generally employ one or
several mobile carts that record from patients in the general hospital
area, special care units, and in emergency rooms, Multiple terminals
from a number of these institutions are linked to a central computer base

to furnish the necessary unit volume,

Larger institutions may employ many carts, both stationary and
mobile, A computer serving a single medical center complex may receive
data from terminals situated in the areas already mentioned, as well as
from outpatient facilities, cardiac catheterization laboratories, and

associated extended care facilities.

Terminals situated in ambulatory care facilities including
clinics, medical foundations, and Health Maintenance Organizations are
foreseeable, Provided that the individual facility can generate a suit-_

able volume of. tracings, the linkage of multiple ambulatory care areas

 

 

 
 

© oe
to a central computer base may be practical. This has not been

demonstrated.

At this time, small groups and solo practitioners recording
‘a limited number of tracings daily would be better served. by gome
other arrangement. In these situations, the cost of data acquisition

carts becomes prohibitive.

IX. Conclusions and Recommendations

Electrocardiographic services are inadequate in many parts
of the country, and a need for improving these services exists. The
magnitude of this need is quite variable, both among different regions
and in different areas of a single region. Organization of, or sub-
scription to, a CAE system may be one approach towards fulfilling
these needs. Several existing CAE systems have demonstrated their
ability to improve both the quality and the availability of electro~
cardiographic services, though problems of cost containment continue.
RMP involvement with CAE systems may be appropriate in some instances

with the following qualifications:

1, Regional needs with respect to electrocardiography must be
‘assessed as part of a more general evaluation of regional resources for
the management of cardiovasculer disease, Attention should be directed
to areas. of: greatest need, and priorities established. ‘Improvement —

of EKG services should not be considered alone but should be part of

a coordinated plan for enhancement of ‘regional health services.
32.

Isolated attempts to upgrade regional EKG capabilities are not con-

sidered to be appropriate roles for RMPs.

2. Regions concerned with upgrading EKG services should consider
several courses of action. Depending upon the availability of exist-
ing resources this may be the establishment of cooperative arrange-
ments between neighboring hospitals, linkages between local institutions
and larger medical center complexes, or use of CAE systems. The |
thorough consideration of all approaches, and selection of the one

best suited to fulfi11 local needs, is of prime importance.

3. Institutions and individuals in regions lacking the necessary
personnel, technology, or volume required for support of an entire
CAE. system may consider gubscription to an established system outside
of the region if such action’ best serves local needs. Individual
RMPs may make ‘available. to interested parties, pertinent information
related to the existence of and the capabilities of these systems.

Such information should be accompanied by the following recommendations:

a. The CAE aystem must provide for validation of individual

EKGs by an experienced electrocardiographer.

b. The service must be available on a twenty-four hour a

day. basis..-

Ce The services: offered by the CAE system must be compatible

with the needs of the utilizer.

 

 

 
33.

d. Careful consideration must be given to all cost factors
including physician validation fees, equipment rental or purchase

costs, transmission charges, and maintenance.

4. Regions possessing the necessary technological expertise,
facilities, and capability for providing a volume of EKGs sufficient —
to support a CAE system, may receive RMP assistance. This may take
the form of technical consultation, organizational counseling, insti-
tutional liaison, and participation in the assessment of regional -
needs, resources, and priorities. RMPs should not assume the respon~-
sibility for provision of start-up and maintenance funds. The poten
tial profit factor inherent to CAE systems makes this the concern of
private industry. Limited monetary support by RMPs may be justified
during the organizational phases of CAE system implementation. Such
funding is specifically intended to assist in establishing suitable
working relationships between participants, provide for technical

consultation, and assist in the evaluation of the proposed system.

5. EKG aystems receiving RMP assistance should possess the

following characteristics:

a. The service offered must be compatible with the needs
of the region and should include both unit validation and twenty-four

hour a day availability.

b. Priority is to be given to extension of the service

into the region so that ‘small and medium sized institutions may

benefit; computerization of electrocardiographic services within a
34.
medical center complex, serving only the components of that complex,
ia not. of the, highest priority. The major objective of the EKG
system should be enhancing the quality and accessability of EKG.

services throughout the region.

Co Utilization of proven hardware, software, and program-
ming components, 80 that immediate benefits can be realized. Emphasis

is to be directed at delivery of service rather than research and

development.

ay An adequate marketing strategy, i. ee, provision for .
the necessary y volume, asaurance of local support and utilization of

the system, and | a service ‘charge compatible with system viability.

ee Total cost to the patient, including validation,
should be comparable, to the customary: -EKG costs of the region, end

preferably less.

6. RMPS should encourage individual RMPs to seek aseistance
from acknowledged experts in the field during the planning and: initi-
ation phases. of any program. RMPs should act as liaison between the

two so that appropriate technical consultation is available to project

proposers.

7. With. respect to extension of computer technology into the
areas of exercise testing and on-line critical care unit monitoring,
both areas must be considered developmental. As such, at the present
time, ‘they lie outside of the direct. objectives of RMPS, i.e., im~

proved delivery of medical care.

 

 

 
APPENDIX I

PARTICIPANTS OF AD HOC COMMITTEE
ON COMPUTER ANALYSIS OF ELECTROCARDIOGRAMS
“AND THE REGIONAL MEDICAL PROGRAMS SERVICE |
November 30, 1971 .

Leonard SCHERLIS, M.D. (Chairman)
-Professor of Medicine

Head, Division of Cardiology ~
School of Medicine

University of Maryland

Baltimore, Maryland

Cesar A. CACERES, M.D.

President, Clinical Systema
Associates, Inc.

Washington, D. C.

Thomas E. CARDILLO, M.D.
: roject Director
@::: Disease Section
ochester Regional Medical Program

University of Rochester Medical Center
Rochester, New York

Leonard DREIFUS, M.D.
Clinical Associate Professor
Hahnemann Medical College and
Hospital of Philadelphia
Philadelphia, Pennsylvania

Robert V. ELLIOTT, M.D.

- Community Electrocardiographic

Interpretative Service Computer
Center
‘Denver, Colorado

Gordon E. ENGEBRETSON, Ph.D.

Associate Director

“Continuing Education

- Plorida Regional Medical Program
Tampa, Florida

Samuel FOX, M.D.
President-Elect,

American College of Cardiology
George Washington University
Washington, D. C.

- Hubert V. PIPBERGER, M.D.

Chief,

VA. Research Center for CVDP
V.A. Hospital

Washington, D. C.

Leon PORDY, M. Dd.

Associate Clinical Professor of
- Cardiology

Mt. Sinai School of Medicine

New York, New York

Mr. T. Allan PRYOR

Intermountain Regional Medical
Program

Salt Lake City, Utah

Arthur E. RIKLI, M.D., M.P.H.
Missouri Regional Medical Program

‘Columbia, Missouri

Ralph SMITH, M.D.
Director

EKG Laboratory

Mayo Clinic
Rochester, Minnesota

Mr. Morris WHITE
Hewlett Packard Company
Waltham, Massachusetts
PARTICIPANTS - Continued

Harold MARGULIES, M.D.
Director 8
_ Regional Medical Programs Service

Edward J. HINMAN, M.D., M.P.H.

Director -

Division of Professional an
Technical Development

John R, FARRELL, M.D.
Chief
Clinical. Specialty Branch, DPTD

Kenneth S. GIMBEL, M.D.
Health Consultant
Clinical Specialty Branch, DPD

Mr. Earle H. BELUE
Health Consultant
- Clinical Specialty Branch, DPTD

 

 

 
HEALTH SERVICES AND MENTAL HEALTH ADMINISTRATION
REGIONAL MEDICAL PROGRAMS SERVICE

AD HOC ADVISORY COMMITTEE
TO REVIEW STATEMENT ON COMPUTER

ANALYSIS OF BLECTROCARDLOGRAMS

Conference Room C - B Wing, 3rd Floor Parklawn Building
10:00 - 3:30 Tuesday, November 10, 1971
Chairman: Leonard Scherlis, M. D,.

AGENDA

I. Introduction and Statement of Purpose - Dr. Harold Margulies

II. Summary of Stafé Report on Computer Analysis of Blectrocardiograns

@ (CAE) = Dr. Kenneth Gimbe1
II, Questions Conerning the Current Functional Status of CAE systems

A. What are the limitations of CAE systems currently being
utilized with respect to accuracy, precision and reliability?

B. Can physician validation of CAE be eliminated?

C. What are the actual time savings in physician man-hours?
(Also in Allied Health and Clinical)

D. Under what conditions are current systems cost-etfectivet
What are the total unit costs?

E. What services should be considered essential to the operation
of CAE? (Optimal turn-around time; interval between analysis
and validation; 24 hour day availability?)

F, What are practical locations for the acquisition units?
What is minimum volume to be cost-effective? —

G. What are alternatives for delivery of improved electro-
cardiographic services in areas of need,

H. What is the role of private enterprise in the development
© and non toring of, GAB?
I, Have CAE programs met with acceptability from. the physician
community in which they are provided? In your practice, do
you accept CAE without further verification?

J. In existing programs, what percentage of operation can be
"considered research and development? oO

K. Under what conditions are CAE justified even if unit cost
exceeds cost for the same service in the same area?

L. Under what conditions would you use CAE as a screening tool? —

~

Iv, Additional questions or presentations (10 minute limit) from participants.

Vv. Adjourn