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Author Topic: What software is needed to interpret cardiac holter monitor data (ECG)?  (Read 18446 times)

Offline erkme73

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First post - please go easy on me...

A year ago last March (3/07) I became gravely ill - going into full septic shock with liver, kidney and lung failure.  I spent 8 days in the ICU with a BP < 60 over palp (MAP <35) for four days.  Aside from some long thoracic nerve damage (from the hypoxia) I recovered fully.  Between the Intensivist, Infectious Disease specialist, and the other 10+ doctors, they were never able to determine a cause for the shock.  At the lowest point, my Apache II scores were 32 (about a 10% survivability).   

Due in part to my age (34) and my otherwise healthy profile, I was able to beat the odds, and surprise most of the doctors.

Within 6 months of my release I was back to long distance bike rides (20 miles per week day, 30-80 miles on weekends).  But, even though (I felt) I was in excellent cardiovascular condition, I still had wildly fluctuating heart rates.  Climbing a single flight of stairs would take my resting HR from 60BPM to 130BMP, and I'd get weak, winded, and dizzy.  More than 2 flights, and I'd have to sit down. 

I went to see a pulmonary specialist who said that it may take up to year to fully recover from the Adult Respiratory Distress Syndrome (ARDS) I suffered while in the hospital.  She assured me that my rapid HR was not lung related, and encouraged me to see a cardiologist - which I did.

The cardiologist put me on a 48 hour heart monitor (holter made by GE) and had me resume my regular exercise routine.  Before returning the monitor, being the techno-geek that I am, I made a copy of the compact flash files for my records.  The files are:

Brentwd.dat (32.5 MB)
event.dat (1kb)
pacedet.dat (1kb)
util.cfg (1kb)

Of course, without a heart monitor analysis program on my PC, these files are useless.  But that's ok - I didn't necessarily need to see them (I wouldn't know what I'm looking at anyway).  The cardiologist reviewed the data and conducted a stress ecg and ultrasound...  All of it perfectly normal.  However, he did say he was surprised at how quickly my HR reached 180BP, how long it took to get <100BPM, and how high my BP went during the test (200/90).  In the end, he said not to worry, and encouraged me to continue working on my cardio exercises.

Fast-forward a year - to today.  Now, nearly 1.5 years since the ICU incident, I still have the exact same symptoms.  The pulmonary doctor has since conducted repeat lung CT scans, and even performed a bronchoscopy - all of which show the lungs to be normal.  She now thinks there is something wrong with cardio - and that by now my ARDS symptoms should have resolved - especially given the long distance biking.  She told me I should go to another cardiologist and get another opinion.

Last week, I visited with the new cardiologist and provided her with a copy of the holter monitor files.  Given that this doctor is NOT a techno-gadget geek like me, she tried to open it on her office PC with Excel. 

This long story brings me (finally) to my question: 

Does anyone know where I can get the PC software that will allow for these files to be opened so I can give the data to the new cardiologist?  I contacted the previous cardio doctor for my medical records, but they only provided the 'consult' of the monitor results - not the actual data.  The new cardiologist said she needs to see the actual data (black and white) vs. the consult report (subjective) otherwise she'll have to tape me to another holter for 48 hours - something I'd like to avoid if possible.

This forum is probably not the right place to ask, but I figured it was worth a shot.  If anyone has any suggestions on where else I might post this request, I'd be grateful.  Thanks...

 
« Last Edit: 03/08/2008 12:49:50 by chris »


 

Offline RD

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Holter LX Analysis Software by NorthEast Monitoring
The Holter LX Analysis Software comes in four levels of functionality: Basic, Enhanced, Enhanced Plus, and Pro.

Each is tailored to address the varied needs of our diverse user community. The software and efficient file structure on which it is built offer the doctor's office, the scanning service or the most demanding cardiac research or clinical applications the fastest and most user-friendly environment.

Compatible with all NorthEast monitors. Industry leading 3 year warranty.

Combine software with your choice of monitors. Monitors sold separately.

Basic Software $1500.00

Enhanced Software $4995.00

Enhanced Plus Software $7995.00

Pro Software $14995.00
http://www.cardiologyshop.com/holxansobyno.html
 

Offline erkme73

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Thanks RD - I found those before, and was hoping there was some free/shareware stuff out there that provided the basic data (as opposed to analytical interpretation).  For that kind of money, I'll have no problem shaving my chest again.
 

Offline RD

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Not sure if this is software is compatible with your Holter files, but its worth a look as a free download of demo software is offered ...

Quote
Our analytical software is compatible with most data formats and with files acquired by the following major data acquisition systems...
If you experience any problems whatsoever with Nevrokard compatibility of your files, you can count on our assistance.
We will make all your files, both pre-existent and future, compatible with Nevrokard.
http://www.nevrokard.eu/


Some Holter files are listed as compatible with Nevrokard software...
http://www.nevrokard.eu/data_formats.htm
« Last Edit: 05/07/2008 17:41:27 by RD »
 

Offline erkme73

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Just downloaded that - thanks - one I had not found after hours of looking.  Unfortunately, while MTI/DAT extensions are available in the format selection, it apparently is not compatible with the *.dat files from my holter.
 

Offline RD

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If you experience any problems whatsoever with Nevrokard compatibility of your files, you can count on our assistance.
 Just email us a short recording done with your data acquisition system and we shall do the rest.
http://www.nevrokard.eu/data_formats.htm

Be warned the Nevrokard software is as expensive Holters.
Maybe you could offer a much smaller one-off payment to the people at Nevrokard to process your Holter ECG data. 
 

Offline RD

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A year ago last March (3/07) I became gravely ill - going into full septic shock with liver, kidney and lung failure.  I spent 8 days in the ICU with a BP < 60 over palp (MAP <35) for four days.  Aside from some long thoracic nerve damage (from the hypoxia) I recovered fully.  Between the Intensivist, Infectious Disease specialist, and the other 10+ doctors, they were never able to determine a cause for the shock.  At the lowest point, my Apache II scores were 32 (about a 10% survivability).   

Due in part to my age (34) and my otherwise healthy profile, I was able to beat the odds, and surprise most of the doctors.

Within 6 months of my release I was back to long distance bike rides (20 miles per week day, 30-80 miles on weekends).  But, even though (I felt) I was in excellent cardiovascular condition, I still had wildly fluctuating heart rates.  Climbing a single flight of stairs would take my resting HR from 60BPM to 130BMP, and I'd get weak, winded, and dizzy.  More than 2 flights, and I'd have to sit down. 

I went to see a pulmonary specialist who said that it may take up to year to fully recover from the Adult Respiratory Distress Syndrome (ARDS) I suffered while in the hospital.  She assured me that my rapid HR was not lung related, and encouraged me to see a cardiologist - which I did.

The cardiologist reviewed the data and conducted a stress ecg and ultrasound...  All of it perfectly normal.  However, he did say he was surprised at how quickly my HR reached 180BP, how long it took to get <100BPM, and how high my BP went during the test (200/90).  In the end, he said not to worry, and encouraged me to continue working on my cardio exercises.

Fast-forward a year - to today.  Now, nearly 1.5 years since the ICU incident, I still have the exact same symptoms.  The pulmonary doctor has since conducted repeat lung CT scans, and even performed a bronchoscopy - all of which show the lungs to be normal.  She now thinks there is something wrong with cardio - and that by now my ARDS symptoms should have resolved - especially given the long distance biking.  She told me I should go to another cardiologist and get another opinion.

Just a thought,
your intermittent high heart rate and high BP could also be of neurological origin, e.g. due to damage of the vagus nerve.
This type of intermittent electrical fault is dysautonomia...
Quote
the heart may race (tachycardia) for no apparent reason (known as Inappropriate sinus tachycardia)
http://en.wikipedia.org/wiki/Dysautonomia
 

Offline erkme73

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Thanks for all the effort... My wife is actually a 2nd year Emergency Resident.  When this all happened to me, she was 2 months shy of graduating with her MD...  Needless to say, I've been seeing all of her friends and professors (neurologists, cardio, gastro, pneumo, etc). 

As for the dysautonomia, it partially fits - at least the part where the heart rate accelerates too quickly.  But it doesn't do it just sitting/lying still.  There has to be some movement to start the event.
 

Offline RD

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As for the dysautonomia, it partially fits - at least the part where the heart rate accelerates too quickly.  But it doesn't do it just sitting/lying still.
 There has to be some movement to start the event.
An intermittent hyperreflexia would require a trigger, not necessarily occur spontaneously.

I prevously mentioned damage to the vagus nerve (cranial nerve X) could cause cardiac dysregulation,
 damage to sympathetic spinal nerves from the thorax could be responsible for a racing heart rate.



http://en.wikipedia.org/wiki/Autonomic_nervous_system
« Last Edit: 06/07/2008 18:28:02 by RD »
 

Offline erkme73

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I will make sure I bring this up at my next Cardio and Neuro appt... thanks!
 

Offline nmunyoz

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There are some free tools in this url:

newbielink:http://www.physionet.org/physiotools/ [nonactive]

Hope it helps
 

Offline erkme73

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I was inevitably unable to get the data converted.  As an alternative, I purchased a Garmin Forerunner 305 which logs heart rate every second for up to four hours.  It's great for checking cardio health relative to exercising (see newbielink:http://www.oakstead.org/workouts [nonactive] for a few test runs).  I used the plotting to discover that I have extreme (60-100%) HR increases while I sleep -  about once every 45 minutes.  This morning I stumbled upon at least one cause...

When I sit relaxed, my resting HR is around 60 BPM.  When I 'stretch' (like you do when you first wake up) and hold that for about 10 seconds, my HR more than doubles!  As soon as I stop stretching, the HR peaks, and drops just as quickly - to about 15 BMP LOWER than it was before the stretch.

Hopefully these uploads will work:



So, in the span of 22 seconds, my HR went from 61 to 123.




It then took only 27 seconds to get back to 61.



1min 30 seconds after starting the stretch, the HR dropped down to 48.

I have a stress test tomorrow (8/11) scheduled with the cardio.  Hopefully this info and the results of the test will shed some light on my concerns.

 
 

Offline RD

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I used the plotting to discover that I have extreme (60-100%) HR increases while I sleep -  about once every 45 minutes.  This morning I stumbled upon at least one cause...

When I sit relaxed, my resting HR is around 60 BPM.  When I 'stretch' (like you do when you first wake up) and hold that for about 10 seconds, my HR more than doubles!  As soon as I stop stretching, the HR peaks, and drops just as quickly - to about 15 BMP LOWER than it was before the stretch.
 

When stretching you are holding your breath: the vagus nerve controls heart and breathing, (see diagram above).
When you stop stretching you begin breathing again, so the coincident irregularities in HR are consistent with a vagus nerve fault.

Other symptoms of vagus nerve fault (short-circuiting) may include:-
Dysphagia: difficulty swallowing, choking.
(O)esophageal spasm: chest-pain like you've got food stuck in your gullet.
Acid reflux: stomach acid in gullet throat, (i.e. frequent and/or severe "heartburn").
Irregular breathing: infrequent and/or shallow breaths. 
« Last Edit: 10/08/2008 13:30:48 by RD »
 

Offline erkme73

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It's definitely a trigger.  so you'd say that this type of 'jump' in HR is not normal, right?

Incidentally, simply holding my breath (and not stretching or tensing muscles) does not result in a change in HR.
« Last Edit: 10/08/2008 13:14:33 by erkme73 »
 

Offline erkme73

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Just repeated this... If I hold my breath to the point of panic - no change.  If I stretch and flex all muscles for 10 seconds (but intentionally keep breathing) I can duplicate the spike.
 

Offline RD

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Your HR graphs look like someone performing the Valsalva manoeuvre, (straining while holding breath)...

Quote
the Valsalva maneuver is performed by forcibly exhaling against a closed glottis (a closed airway).
This maneuver with slight modifications can be used as a test of cardiac function and autonomic nervous control of the heart



http://en.wikipedia.org/wiki/Valsalva_maneuver

HR Increasing from 60 to 120 bpm in 10-15 seconds, (straining and holding breath).

If you do have dysautonomia, medication used to treat epilepsy (anti-convulsants) can be effective.
« Last Edit: 10/08/2008 14:28:17 by RD »
 

Offline RD

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Graph of heart rate while sleeping (of athlete)...



http://www.jssm.org/vol2/n4/2/v2n4-2pdf.pdf
 

Offline erkme73

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Here's mine when sleeping:

 

Offline RD

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Your "sleeping2" graph superimposed on sleeping athlete graph...



This illustration is an approximate comparison of HR: your average HR is actually lower than the athlete's.
« Last Edit: 11/08/2008 09:35:22 by RD »
 

Offline jkent

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Can you send me your .cfg file ? I don't know the specific package needed to
interpret the data but I can have a look, starting at the .cfg. No guarantees of course.
 

Offline erkme73

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Sure, in fact you can download the data here:

newbielink:http://www.dilo.com/eric/medical/hm.zip [nonactive]

I thought it was a GE monitor, but have been since told it was not.  Given the BRENT file name, the GE specialist I talked to said it is likely a competing model.

FWIW, I had my visit with second cardiologist yesterday, who said she "was not impressed" with the results - which, in cardio-humor, is a good thing.  She said that the 11 min it took to get to 160, and the 5 min it took to get below 100 is completely normal, and that I'm probably just expecting too much of myself.

Admittedly the HR did climb slowly, and drop quickly - but upon biking, it jumps from 80 to 130 in < 1 min.  She said not to be concerned.  This is now the second doctor saying the same thing, so I guess I'm ok (famous last words).  Just don't want to pull a Tim Russert.
 

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