SV: ECG archetype advice required

Ian McNicoll ian.mcnicoll at
Thu Sep 6 03:31:45 EDT 2018

I agree with /min. I doubt if the dicom approach has much real world
traction. Fhir seems to have picked /min and is much more likely to have
majority take up.


On 6 Sep 2018 at 07:50, <Ivar Yrke <iyr at>> wrote:

Give people options and they will end up with variation. It is NOT WRONG to
use {H.B.}/minute, nor would it be wrong to use liters{blood}/minute or
meters{travelled}/second. It is just unnecessary overkill(!). Adding {H.B.}
to a value that is itself a pure dimensionless number only adds value when
the magnitude is taken out of context. But out of context the magnitude
itself becomes meaningless, whichever meaning you add to the number.

No need to follow the path of Dicom here, converting between the two is

Vennlig hilsen

*Ivar Yrke*

Senior systemutvikler

Telefon +47 75 59 24 06

Mobil +47 90 78 89 33

*Fra:* openEHR-clinical [mailto:openehr-clinical-bounces at] *På
vegne av* Heather Leslie
*Sendt:* 6. september 2018 07:44
*Til:* For openEHR clinical discussions <openehr-clinical at>
*Kopi:* For openEHR technical discussions <
openehr-technical at>
*Emne:* RE: ECG archetype advice required

Hi everyone,

Thanks for the rapid response and clinical/modeller consensus of 3,
regarding units of frequency for heart rate as 1/min

I’ve now included the technical list in this thread as I’ve found this
reference to a DICOM standard -
– particularly Table TIC 3713, see below.

Atrial heart rate is a synonym of at0094 ‘PP rate’ in the latest version of
the archetype -

Ventricular heart rate is a synonym of at0013 ‘RR rate’.

In both examples the units from this Dicom document are {H.B.}/min.




*From:* openEHR-clinical <openehr-clinical-bounces at> *On
Behalf Of *Marcus Baw
*Sent:* Wednesday, 5 September 2018 5:50 PM
*To:* For openEHR clinical discussions <openehr-clinical at>
*Subject:* Re: ECG archetype advice required


I would echo Ivar's comments - keep it simple and use 1/min. It is clear we
are talking about the rate of cardiac electrical activity from the context.
The use of the word 'beats' would also undoubtedly (rightly) come under
fire from cardiological/intensivist pedants like me - as a 'beat' is an old
word deriving from the *observation of heart sounds*, whereas what you are
measuring is cardiac electrical activity - and it's perfectly possible for
the two to be different things, as in a PEA cardiac arrest.

Also, any of the more specific units such as '{beats}/min' could possibly
confuse and make it harder to programmatically compare or display alongside
other clinically relevant 'frequencies' expressed as 1/min such as:
frequency of ventricular pacing spikes, frequency of aortic balloon pump
counterpulsations, etc


On Wed, 5 Sep 2018 at 08:39, Ivar Yrke <iyr at> wrote:

1/min, definitely!

Cardiac output is measured as liters/minute. Liters of what? We could have
used the unit liters{blood}/minute, but I have never seen that done. It is
considered obvious from the context. Likewise with other units. Velocity is
measure as meters/second, not meters{travelled}/second. One could argue
that meters{travelled} makes it clear that it is not meters{altitude}, but
that is generally considered obvious from the context.

For some reason there is this temptation to add a fictive unit ({beats},
{count} etc.) when the number itself is unit less. This is not necessary.
The context is always sufficient, just like in the cases that have a unit.
Let us cut through the unclarity of UCUM and keep it simple and basic.

My argument is probably influenced by my background as a physicist. But if
no one has objected to 1/min in pulse/heartbeat, then I see no reason to
deviate from the basics in ECG or to modify pulse/heartbeat.

Vennlig hilsen

*Ivar Yrke*

Senior systemutvikler

Telefon +47 75 59 24 06

Mobil +47 90 78 89 33

*Fra:* openEHR-clinical [mailto:openehr-clinical-bounces at] *På
vegne av* Heather Leslie
*Sendt:* 5. september 2018 08:00
*Til:* For openEHR clinical discussions <openehr-clinical at>
*Emne:* ECG archetype advice required

Hi everyone,

I’ve just been facilitating the most recent reviews on the ECG archetype
and would appreciate some advice on two issues.

The current atrial and ventricular rates are modelled as a Quantity
(frequency) ie 1/min. However UCUM is unclear and there seems to be a few
options, including {Beats}/min, {beats}/min and {H.B} is represented in
another context, so maybe {H.B}/min is valid as well. Note that if we
decide that it is appropriate to modify to one of these specific UCUM
units, then to be consistent we will need to consider modifying the
Pulse/heartbeat OBSERVATION as well – currently also modelled as a
frequency of 1/min.

In addition, I’d appreciate some advice as to how we could get access to
the latest draft of the ISO/IEEE standard for ECG – I think it is ISO/IEEE
11073-10406. We’d like to make sure there is alignment between the standard
and the archetype before further reviews.

Kind regards


*Dr Heather Leslie*


M +61 418 966 670

Skype: heatherleslie

Twitter: @atomicainfo, @clinicalmodels & @omowizard

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