CardioScan Internal_Interpret-Holter-Reports

cardioscan.co

How to interpret a
CardioScan Holter
ECG report

by Assoc Prof Harry Mond, Medical Director of CardioScan

| OAM | MBBS | PHD | MD | FRACP | FCSANZ | FACC | FHRS

How to interpret a CardioScan Holter ECG report

Globally recognised RClianicpailldy siNgnaifictainotnfinadilngs
Hospital RolloutWe alert your clinic immediately via SMS,
qualifications
email or phone should we uncover any
All CardioScan cardiac
technicians /cardiac clinically significant findings, including:
physiologists are tertiary
educated and must • Ventricular fibrillation/Torsades de Pointes
have completed at least
one of the following • Ventricular tachycardia (6 beat or more)
university qualifications:
• Very frequent ventricular ectopics (>10%)
• Bachelor of Biomedical
• Sustained supraventricular tachycardia
Science At amgolarencthean 30 seconds

• Bachelor of Science; or •• 1Pr0e0-Kexacintatticioinp/aWteodlff-EPCaGrkinvsoolun-mWehi/teannum

Bachelor of Nursing •• EPaDrAoxNys1m2a0l1/shusatardinwedaraetrwialitfhibrillation/flutter
100% live transmission
Additionally, they must •
have completed: Complete atrial fibrillation/flutter with rapid

• Certificate III in • Bveilnlitnrgicuslearrvraicteess(ianvcelruadgeedrate >110 bpm)

Electrocardiography • 2:1 second degree AV block or High degree AV block
for Cardiac Technicians
or equivalent • Complete heart block

• Certified Cardiac • Pauses (3.0 seconds or longer)

Technician (global) • Marked ST elevation/depression
qualification

These requirements need
to be met by all of our
clinical teams worldwide.

Alerting you to significant findings

All clinically significant findings will be marked as
urgent and will appear at the top of your Analysed
Holters list in BeatBox, highlighted by an Urgent tag.

Additional means of alert may be implemented
on agreement with customer, where necessary.

Contact us CardioScan Singapore CardioScan Hong Kong
E: [email protected] E: [email protected]
CardioScan Australia
E: [email protected] CardioScan Malaysia CardioScan UK
E: [email protected] E: [email protected]
Cardiac Monitoring Service (USA)
E: [email protected]

2

Analysed report notes

We provide a comprehensive analysed report with a range of disclosures
and inclusion, as detailed throughout this document. The following provides
a brief overview of common clinical notes you may see in our reports:

Rhythm and major abnormalities Analysed by

The first line of the clinical interpretation The interim report generated by
of data analysed is to capture the key the Cardiac Physiologists are finally
features identified in the study. It will tagged by “Analysed by CardioScan"
include the predominant rhythm the
patient was in, presence of pacemaker Alert markers
activity, AV blocks, significant ST/T
changes and most importantly any Our team uses # markers to direct
other significant arrhythmia. reporting actions and these may be
visible in the initial analysed PDF you
Patient triggered/diary events receive. We also use hashtags as
codes for certain clinical outcomes.
Patient triggered/diary events and their However, these will be automatically
corresponding ECG rhythm and events removed when the report is finalised.
are provided. If there were no triggered
events, then “No patient triggered events” Common alert markers include:
comment will be added to the report.
#Repeat – which tags report to
Poor quality trace (if required) alert a clinic of the need to repeat
a test, and includes the reason for
“Poor quality trace” if data is quality repeating the test (eg. Insufficient
is poor throughout or “Intermittently data/study, poor quality trace etc.).
poor quality trace” may be added to
conclusion if quality of data is variable. #Urgent – this tag ensures the report
This may be associated at the end of the will appear at the top of the Analysed
conclusion with a phrase “Suggest repeat report list in BeatBox and triggers
study for a more comprehensive result, if an urgent alert to customers.
clinically indicated” if available data may
not be sufficient enough or quality may
mask any clinically significant events.

3

How to interpret a CardioScan Holter ECG report

Section 1 summarises the

Recorded
data

Includes:
• Patient and Customer information
• Summary of findings
- Heart Rate
- Ventricular ectopy
- Heart rate variability
- ST segment analysis
- S upraventricular ectopy
- Pauses
• Significant events
- P ie charts of burdens (in

multiday report)
- s ample strips of significant events
- bradycardia/tachycardia
• Interim conclusion

4

Section 1 - Recorded data

5

How to interpret a CardioScan Holter ECG report

Patient information

Customer/referring doctor information and clinical notes/indications for study.

Heart rate Analysed beats
total number of QRS beats
Minimum/maximum HR-4 Intervals captured/analysed by software
Minimum/maximum heart rate based
on 4 R-R intervals over study period Analysed minutes
total minutes of analysable data available
Average HR-24 Hours
Average heart rate over study period ECG monitoring period
total minutes of study
Minimum/maximum HR-hourly
Minimum/maximum average, hourly
heart rate over study period

Ventricular ectopy VE's per-1000
average number of ventricular ectopics
VE total per 1000 total beats captured
total ventricular ectopics captured
VE's per-hour
V-pair total average number of ventricular
total ventricular ectopic ectopics per hour study period
couplets/pairs captured
VE burden%
WCT total the percentage beats that are VE's of
total Wide Complex Tachycardia total beats captured ie. percentage of VE
runs of 3 beats or more captured Total out of Analysed Beats captured

Max WCT duration Ventricular R on T
number of beats of the longest run of number of ventricular ectopics caused by
wide complex tachycardia, including a ventricular depolarization superimposing
average rate and time during study on the previous beat's repolarization

Maximum/minimum HR in WCT
maximum/minimum average heart rate of
wide complex tachycardia runs captured

Heart rate variability

Presented in time domain indices with the simplest variable, the standard
deviation of normal to normal R-R intervals, referred to as the SDNN, usually
calculated over a 24-hour period and respective Spectral Power.

6

Section 1 - Recorded data

7

How to interpret a CardioScan Holter ECG report

ST segment analysis Max ST episode
longest duration of ST episode
Total minutes of ST in 3 channels
Max HR in ST episode
Max delta ST depression Maximum heart rate of
maximum ST depression (mm) longest ST episode

Max delta ST elevation All values are based on findings
maximum ST elevation (mm) for first 24 hours of study.

Supraventricular ectopy SVE's per-1000
average number of supraventricular
SVE total ectopics per 1000 total beats captured
total supraventricular ectopics captured
SVE's per-hour
SV-Run total average number of supraventricular
total number of supraventricular ectopics per hour study period
runs of 3 beats or more captured
SVE burden%
Longest SV-Run the percentage beats that are SVE's of
number of beats of the longest total beats captured ie. percentage of
SV-Run, including average rate SVE Total out of Analysed Beats captured
and time during study
Total aberrant beats
Maximum HR in SV-Run total number of supraventricular ectopics
maximum average heart rate and runs with aberrancy captured
of SV-Runs captured

Pauses Time of max QTc
date/time and heart rate the
Pauses in excess of 2.00 sec longest QTc was captured
total number of pauses of
2.00 seconds or more IdioV
total number of idioventricular
Max pause runs captured
the duration of the longest
pause and time of event All values for QT/QTc are based on findings for
first 24 hours of study using the Bazett's formula.
Max QT
longest QT interval and channel used

Max QTc
longest QTc duration

8

Section 1 - Recorded data

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How to interpret a CardioScan Holter ECG report

Significant ECG events Sample strips of most significant events:
• Min HR
Pie charts of burdens
Pie chart percentage proportion of study • Max HR
(burden) in atrial fibrillation, ventricular
and supraventricular ectopics. Only • Most significant ventricular event
available for multiday studies. Values
are otherwise provided in table above. • Most significant supraventricular event

Periods of study in bradycardia (<50 bpm) • Longest R-R (only available
and tachycardia (>100 bpm) in 24 hour report)
Percentage burden is proportion
of Total Minutes in bradycardia or • ST Segment (only available
tachycardia out of Analysed Minutes in 24 hour report)

Interim conclusion ‡ Line 6
Supraventricular ectopy
Line 1
May include some # markers used Line 7
to create alerts within BeatBox. Pauses

Line 2 Line 8
May include study period, Patient triggered/diary events
if multiday study
Line 9
Line 3 Initials of analysis tech
Predominant rhythm with any AV
blocks or other significant arrhythmia Ectopy frequency is based on Legend
for Ectopic Activity provided *
Line 4
Average, Minimum and (% burden included in conclusion of
Maximum heart rates report only if frequent or more)

(Min and Max rates are based on For further detailed information, please
averages of 4 R-R intervals) see Guideline for Reporting Holter Studies

Line 5
Ventricular ectopy

Please note: ‡ detailed description of conclusion format
is outlined in the "Holter Conclusion
* No formal guidelines for grouping and quantifying ectopy frequency
has been provided in Cardiology. CardioScan has endeavoured Format Guidelines" document
to create a guideline based on its experience with ambulatory
reporting. The aim is to provide some consistency in our reporting
and also highlight significance of events, where necessary.

10

Section 1 - Recorded data

Pie charts of burdens

Sample Strips

Legend for Ectopic Activity

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How to interpret a CardioScan Holter ECG report

Section 2 summarises the

24 Hour
trends

Includes:
• Heart rate
• Max delta ST deviation
• Heart rate variability
• Spectral power
• VE beats per hour
• SVE beats per hour
• Pause per hour
• Hourly tabular summary

12

Section 2 - 24 Hour trends

13

How to interpret a CardioScan Holter ECG report

Heart rate Heart Strip

Graph • Maximum heart strip for 24-hour
A graph trend of maximum, average study period
and minimum heart rate
• Minimum heart strip for 24-hour
study period

Max delta ST deviation

ST deviation (elevation/depression) graph
The incidence of ST segment depression in ambulatory ECG recordings is high
particularly with rapid heart rates and baseline artefact and does not always
indicate myocardial ischaemia. However, although false positive diagnosis may
be common, it can be useful sometimes when significant depression is noted,
especially in the presence of patient symptoms. Also ST elevation can occasionally
be seen with transmural ischaemia, such as severe coronary atherosclerotic
obstruction or spasm and may be extremely useful in specific situations,
where the exercise test is unhelpful and Prinzmetal angina is suspected.

Strip
Sample strip of a significant ST event, if any.

Though sensitivity and specificity of ST segment changes captured
may be poor on an ambulatory Holter study due to baseline artefact,
significant ST/T wave changes will be highlighted in the report to
be assessed on clinical significance to patient presentation.

Heart rate variability Histogram
Heart rate variability histogram
Graph of R-R intervals and frequency
24 hour heart rate variability trend over 24 hour period

14

Section 2 - 24 Hour trends

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How to interpret a CardioScan Holter ECG report

Spectral power * Common Frequency Domain
HRV metrics include:
Histogram
Histogram of hourly total Spectral Power • High Frequency power (HF): frequency
activity in the 0.15 - 0.40Hz range
Graph (green in the above chart)
Frequency Domain Analysis is a complex
analysis technique that shows how • Low Frequency power (LF): frequency
much of a signal lies within one or more activity in the 0.04 - 0.15Hz range
frequency bands (ranges). With regards (yellow in the above chart)
to Heart Rate Variability, research has
identified certain frequency bands • LF/HF Ratio: A ratio of Low Frequency
that tend to correlate with certain to High Frequency. Some consider
physiological phenomenon, such as this indicative of Sympathetic
Parasympathetic nervous system activity. to Parasympathetic Autonomic
Balance, but that is controversial.

VE beats per hour Run
Sample ventricular run event, if any
Histogram
Hourly ventricular ectopy count

SVE beats per hour Run
Sample supraventricular run event, if any
Histogram
Hourly supraventricular ectopy count

Pause per hour Strip
Sample strip of a pause, if any
Histogram
Hourly count of pauses 2.0
seconds or more.

Please note:

* Values presented regarding Spectral Power has to taken in context of overall

quality of data. Also this is only of any significance in specialised cardiac
study scenarios. Otherwise, this can be ignored in the report.

16

Section 2 - 24 Hour trends

17

How to interpret a CardioScan Holter ECG report

Hourly tabular summary
• Time
• Average Maximum and

Minimum Heart Rates (bpm)
• Heart rate variability
• Maximum ST depression or elevation in

each channel and duration (minutes)
• Number ventricular ectopy events
• Number of supraventricular

ectopy events
• Number pauses of 2.0

seconds or more
• Number of idioventricular rhythm

18

Section 2 - 24 Hour trends

19

How to interpret a CardioScan Holter ECG report

Section 3 contains the

ECG
strips

Includes:
• Sample strips of relevant

findings during study

20

Section 3 - ECG strips

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How to interpret a CardioScan Holter ECG report

Sample strips of relevant findings during study

• Baseline rhythm strip ECG strips presented are in 8 second strip
format with a 1 minute rhythm strip (ie.
• Significant arrhythmia events 30 second rhythm on either side of the
(eg. atrial fibrillation or flutter, event) of the primary channel analysed
escape rhythm, AV blocks etc)
Onsets and offsets of longer events
• Longest R-R strip will be provided, where necessary

• Ventricular/supraventricular ectopy Patient triggered events will be labelled
as "Event" and any diary symptoms
- isolated ectopics will be annotated to the label (eg.
Event-Palpitation), if provided
- couplets
ECG strips are sorted alphabetically
- runs and is not changeable

- bigeminy/trigeminy On myPatch device using an
adult electrode, the 3 channels
• pauses 2.0 seconds or greater recorded are representative of:

• patient triggered or diary events • Channel 1: LL-RA=LEAD II modified

Standard procedure is to save 1 event • Channel 2: LL-LA=LEAD III modified
Baseline rhythm and Longest R-R), 3
events of non-significant events (eg. • Channel 3: V5-V_w=V5
isolated ectopics, couplets and bigeminy/
trigeminy) and save 3-5 events of
more significant findings (eg. pauses,
ventricular or supraventricular runs,
atrial fibrillation or flutter, idioventricular
rhythm and other arrhythmia)

22

Section 3 - ECG strips

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How to interpret a CardioScan Holter ECG report

Section 4 contains the

Fib/Flu
report

and full disclosure
rhythm strips

Atrial fibrillation/flutter (Fib/Flu) report includes:
• 24 hr breakdown of episodes
• Heart rate trends
• Additional page(s) provided, if

study longer than 6 days

24

Section 4 - Fib/Flu report and full disclosure rhythm strips

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How to interpret a CardioScan Holter ECG report

24 hr breakdown of Heart rate Additional page(s)
episodes trends of daily breakdown
provided if study
24 hour breakdown of 24 hour heart rate longer than 6 day
atrial fibrillation/flutter trends highlighting atrial
episodes, in minutes, fibrillation/flutter episodes. 6 day breakdown of atrial
burden and heart rates fibrillation/flutter episodes,
(average, minimum and in minutes, burden.
maximum).

24 hr breakdown of episodes Heart rate trends

6 day breakdown of episodes

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Section 4 - Fib/Flu report and full disclosure rhythm strips

Full disclosure rhythm strips Usually not included unless requested by
customer for review purposes or specific
Available in 30 minutes (only available hourly strips will be provided as visual
for 24 hour studies) or 1 hour per page enhancements for some significant
option. Only the best of 3 channels to be arrhythmia captured.
provided.

27

How to interpret a CardioScan Holter ECG report

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cardioscan.co

CardioScan was established 30+ years ago by our Medical Director Assoc Prof Dr
Harry Mond, ands has grown today to one of the largest services of its kind globally,
overseeing more than 500k+ heart studies annually – operating in 10 countries
including UK, US, Australia, Hong Kong, Malaysia and Singapore, among others.

Contact us CardioScan Singapore CardioScan Hong Kong
E: [email protected] E: [email protected]
CardioScan Australia
E: [email protected] CardioScan Malaysia CardioScan UK
E: [email protected] E: [email protected]
Cardiac Monitoring Service (USA)
E: [email protected]