HL7 aECG Implementation Guide
Final
March 21, 2005
Sponsored by:
Regulated Clinical Research Information Management
Technical Committee
Principal Contributors:
Barry D. Brown
Mortara Instrument, Inc.
barry.brown@mortara.com
Fabio Badilini
A.M.P.S. llc
badilini@amps-llc.com
HL7 aECG Implementation Guide
Final 21-March-2005 Page 2 of 101
Table of Contents
HL7 aECG Implementation Guide................................................................................................... 1
Table of Contents..................................................................................................................................................2
Introduction..........................................................................................................................................................4
Glossary................................................................................................................................................................5
aECG Parts Explained..................................................................................................................... 7
AnnotatedECG
(required)
..................................................................................................................................7
ClinicalTrialProtocol
(optional)
...........................................................................................................................9
ClinicalTrial
(required)
.....................................................................................................................................10
ClinicalTrial Author
(optional)
..........................................................................................................................11
ClinicalTrialSponsor.........................................................................................................................................11
SponsorOrganization.......................................................................................................................................11
ClinicalTrial Location
(optional)
........................................................................................................................12
TrialSite.........................................................................................................................................................12
Location.........................................................................................................................................................12
ClinicalTrial ResponsibleParty
(optional)
...........................................................................................................13
TrialInvestigator.............................................................................................................................................13
InvestigatorPerson .........................................................................................................................................13
Subject
(required)
..........................................................................................................................................14
TrialSubject
(required)
....................................................................................................................................14
SubjectDemographicPerson
(optional)
.............................................................................................................14
SubjectAssignment
(required)
.........................................................................................................................16
SubjectAssignment Definition
(optional)
...........................................................................................................16
TreatmentGroupAssignment............................................................................................................................16
TimepointEvent
(required)
..............................................................................................................................17
TimepointEvent Performer
(optional)
...............................................................................................................17
StudyEventPerformer
(optional)
.......................................................................................................................17
StudyEventPerformer AssignedPerson..............................................................................................................17
AnnotatedECG Definition
(optional)
.................................................................................................................19
RelativeTimepoint...........................................................................................................................................19
ProtocolTimepointEvent ..................................................................................................................................19
ReferenceEvent..............................................................................................................................................19
AnnotatedECG Location
(optional)
...................................................................................................................21
TestingSite.....................................................................................................................................................21
Location
(optional)
.........................................................................................................................................21
AnnotatedECG ControlVariable
(optional)
.........................................................................................................22
RelatedObservation ........................................................................................................................................22
RelatedObservation Author .............................................................................................................................22
AssignedEntity................................................................................................................................................22
AssignedAuthorType.......................................................................................................................................22
AssignedPerson..............................................................................................................................................22
AssignedDevice..............................................................................................................................................22
PlayedManufacturedDevice..............................................................................................................................23
ManufacturingOrganization .............................................................................................................................23
RepresentedAuthoringOrganization..................................................................................................................23
Identification..................................................................................................................................................23
AnnotatedECG PertainsTo
(optional)
................................................................................................................25
SubjectFindingComment .................................................................................................................................25
Author
(optional)
............................................................................................................................................25
AnnotatedECG Component
(optional)
...............................................................................................................26
Series ............................................................................................................................................................26
Series SeriesAuthor
(optional)
.........................................................................................................................28
manufacturedSeriesDevice
(required)
..............................................................................................................28
manufacturerOrganization
(optional)
...............................................................................................................28
Series SecondaryPerformer
(optional)
..............................................................................................................30
seriesPerformer
(required)
..............................................................................................................................30
assignedPerson
(optional)
...............................................................................................................................30
Series Support
(optional)
................................................................................................................................31
supportingROI................................................................................................................................................31
Boundary.......................................................................................................................................................31
Series ControlVariable
(optional)
.....................................................................................................................33
SequenceSet
(required)
..................................................................................................................................34
SquenceSet ControlVariable
(optional)
.............................................................................................................34
Sequence
(required)
.......................................................................................................................................35
HL7 aECG Implementation Guide
Final 21-March-2005 Page 3 of 101
Sequence ControlVariable
(optional)
................................................................................................................36
Series SubjectOf
(optional)
..............................................................................................................................37
AnnotationSet
(required)
.................................................................................................................................37
AnnotationSet Author
(optional)
......................................................................................................................37
AnnotationSet ControlVariable
(optional)
..........................................................................................................37
See the series control variable discussion for additional details and examples.....................................................37
This is an example of the ECG recording device authoring a set of automatic annotations:..................................37
This is an example of a ECG core laboratory technician authoring a set of annotations:......................................38
AnnotationSet Component
(optional)
...............................................................................................................39
Annotation.....................................................................................................................................................39
supportingROI................................................................................................................................................39
Boundary.......................................................................................................................................................40
Appendix A: Discussion of UIDs .............................................................................................. 42
Appendix B: Discussion of Codes and Coding Systems ......................................................... 44
Appendix C: Discussion of Timestamps................................................................................... 45
Appendix D: Required Information ........................................................................................... 47
Appendix E: Discussion of ECG Context ................................................................................. 49
Appendix F: Linking CDISC SDTM to HL7 aECG ................................................................... 50
Appendix G: Examples of Common ECG Annotations ............................................................ 51
QRS-Wave Annotation ....................................................................................................................................51
T-Offset Annotation........................................................................................................................................51
P-Wave Annotation.........................................................................................................................................52
R-Peak Time Annotation .................................................................................................................................52
R-Peak Amplitude Annotation..........................................................................................................................53
QT Interval Annotation ...................................................................................................................................54
QTc Interval Annotation..................................................................................................................................56
Interpretation Statement Annotations..............................................................................................................58
Appendix H: FDA Considerations ............................................................................................ 60
Appendix I: Vocabulary Reference ......................................................................................... 62
Subject gender....................................................................................................................................................62
Subject race........................................................................................................................................................63
White.............................................................................................................................................. 65
Region of interest................................................................................................................................................66
Observation series type........................................................................................................................................67
Observation sequence type..................................................................................................................................68
ECG Leads ..........................................................................................................................................................69
ECG Annotations .................................................................................................................................................73
Control variable...................................................................................................................................................92
Control variable...................................................................................................................................................92
Vocabularies not yet defined ......................................................................................................... 95
Reason of the ECG ..............................................................................................................................................95
Confidentiality of the ECG ....................................................................................................................................96
Reason of the Time Point Event............................................................................................................................97
Subject role.........................................................................................................................................................98
Device code ........................................................................................................................................................99
Annotation Methods........................................................................................................................................... 101
HL7 aECG Implementation Guide
Final 21-March-2005 Page 4 of 101
Introduction
The Annotated ECG (aECG) HL7 standard was created in response to the FDA’s digital ECG
initiative introduced November, 2001. The FDA continues to be concerned about evaluating non-
cardiac drugs for negative cardiac effects, like prolonged QT. Before this initiative, sponsors
were already submitting ECG findings tabulations (e.g. QT interval measurements) with their
applications. However, the FDA could not systematically evaluate the ECG waveforms and
measurement locations those findings came from. Most (if not all) ECGs in current trials were
collected with paper and not electronically retained. The next logical step for the FDA was to ask
for the digital waveforms and measurement locations (annotations) be made available with the
application.
A necessary step for submitting the ECG waveforms and annotations to the FDA was to have a
standard format for the data. An evaluation of current ECG waveform standards found no
existing standards that met all the FDA’s needs. Therefore the FDA, sponsors, core laboratories,
and device manufactures worked together within HL7 to create a standard to meet the needs.
The aECG standard was created by HL7’s Regulated Clinical Research Information Management
(RCRIM) in response to the FDA’s need. It passed final balloting in January, 2004, and was
accepted by ANSI May, 2004. The January, 2004 version is the format the FDA expects to
receive all annotated ECGs in. Some early adopters started creating ECGs using an
intermediate version that HL7 balloted around April, 2003, but it’s not known if or for how long the
FDA will accept ECGs in that draft format.
This implementation guide (IG) offers supplemental material for the January, 2004 aECG
standard. It does not by itself provide all the information required to fully implement the standard.
This IG should be used in conjunction with the HL7 aECG standard as well as the standard’s
XML schema and example aECG file. Viewing the schema in a graphical presentation tool, such
as XMLSPY, will help a great deal in understanding the XML structure including which elements
and attributes are required or optional, and which datatypes to use. The aECG sample can be
viewed using Internet Explorer or an XML tool such as XMLSPY or oXygen XML Editor.
Even though the aECG standard was created in response to the FDA’s need to have ECG
waveforms and annotations, it does not mean that it can not be used for other purposes. For
example, ECG core laboratories may choose to give sponsors the annotated waveforms using
this standard as well. The lab may pass extra data to the sponsor that the sponsor would not
normally want to pass to the FDA. The standard is quite flexible and is capable of
accommodating the additional uses. The IG presents information about the aECG standard
independently of any particular use. FDA specific issues are left to an appendix.
Anything in this IG that contradicts the official HL7 standard or FDA guidance should be ignored.
The official standard and FDA guidance take precedent over this IG. This IG is written to the best
of the authors’ understanding of the standard and current FDA guidance.
HL7 aECG Implementation Guide
Final 21-March-2005 Page 5 of 101
Glossary
• aECG – Annotated ECG. The name given to a file or message conforming to HL7’s
“Annotated ECG” standard. It contains one or more series of ECG waveforms pertaining
to a relative time point and a set of derived ECG findings for that time point.
• Annotation – An observation made on or associated with a series. E.g. a P-wave onset,
a period of atrial fibrillation, the point at which a drug dosage was administered, etc.
• CDISC – Clinical Data Interchange Standards Consortium, an open, multidisciplinary,
non-profit organization committed to the development of industry standards to support the
electronic acquisition, exchange, submission and archiving of clinical trials data and
metadata for medical and biopharmaceutical product development. The mission of
CDISC is to lead the development of global, vendor-neutral, platform independent
standards to improve data quality and accelerate product development in our industry.
• Code – A computer-interpretable string (mnemonic) who’s meaning is defined by a code
system.
• Code System – A set of one or more codes with definitions assigned by the code
system.
• Code System UID – An identifier assigned by HL7 to uniquely identify a code system.
• Digital ECG – A collection of digital information that contains ECG waveforms
represented as sequences of numbers.
• Digital Electrocardiograph – A microprocessor-controlled electrocardiograph that
captures the ECG waveforms using analog-to-digital converters and stores the
waveforms as sequences of numbers. It produces digital ECGs.
• Electrocardiograph – A device that records the electrical activity of the patient’s heart by
tracing voltage-vs-time waveforms on paper.
• Electrocardiogram – Traditionally 12 waveforms (leads) arranged on a piece of paper
representing 10 seconds of cardiac activity while the patient is lying on his back at rest. It
is the physical record of the patient’s cardiac activity produced by an electrocardiograph.
• ECG – Electrocardiogram. The term has also been used to mean any set of cardiac
waveforms (leads) representing any contiguous period of time.
• Control Variable – A special type of code (and optional value) describing some aspect of
the observation method. E.g., the device settings of an electrocardiograph
•
Lead – A vector along which the heart’s electrical activity is recorded as a waveform.
• MDC – Code system name given to ISO 11073-10101 (IEEE-1073) Medical Device
Communications nomenclature by HL7. Source of the ECG leads, control variables, and
annotation codes.
• Nomenclature – see code system.
• OID – Object Identifier. A managed scheme for producing unique identifiers in the form
of period-separated-integers assigned in a hierarchical manor much like DNS names are
assigned on the Internet. Organizations are assigned a prefix, and the organization is
responsible for allocating identifiers using their prefix.
• Reference Event – An event defined by a study protocol to which relative time points are
anchored. E.g. a meal, a drug dosage, etc.
• Relative Time point – A time point relative to the reference event. E.g. 30 minutes post
dosage.
