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Fun and games with response time reporting

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As I've mentioned on several different occasions, it's a huge mistake to wait until a tragedy occurs to explain the truth about response times to your community.

Response times should be measured from the patient's perspective. In other words, from the moment the dispatcher picks up the phone and says, "9-1-1 what is your emergency?" to the moment a professional rescuer arrives at the patient's side.

Any other sub-interval is smoke and mirrors (see HERE and HERE for previous posts on EMS response time reporting and other system failures).

There is no excuse for allowing our real response times to be ambiguous. It doesn't matter if some other organization does the dispatching. It's the EMS system’s responsibility to figure it out because we are ultimately responsible for the community's chain-of-survival.

In other words, if our chain-of-survival is broken (and it surely is if we have no idea how long call processing takes) then it's our responsibility to educate our citizens and our elected officials of that fact.

Remember, millions (perhaps tens or even hundreds of millions) of dollars in 9-1-1 taxes are collected each year in the United States. Where does the money go? Our inability (or unwillingness) to measure "9-1-1 call received" to "patient's side" is completely unacceptable and patients die because we pretend that our response times are better than they actually are.

Where's the accountability?

We must never allow ourselves to become acclaimated to things that would outrage members of the general pulbic once the facts become known.

Explaining why EMS wasn't there "in 4 minutes" to treat a child in cardiac arrest is not a particulary good backdrop to have this conversation with the taxpayers.

Posted by on June 30, 2011 • Filed under: ems-topics, patient-management • Tagged: , , , , , , ,

13 year old female CC: Syncope – Discussion

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This is the discussion for 13 year old female CC: Syncope.

You may wish to go back and familiarize yourself with the details.

The short of it is that on a very hot and humid day a 13 year old female passed out after looking at her sister's scraped knee. She had passed out at the sight of blood before.

The parents were not the ones who contacted 9-1-1 and they were not interested in having the patient transported to the hospital by ambulance.

However, the family history was very concerning as the father's brother died (many years ago) at age 16 from a "seizure disorder." 

Prudently, the treating paramedics obtained consent for an exam and obtained a 12-lead ECG.

I had posed the following questions:

  • Why did the paramedics ask questions about the family history?
  • Why did the paramedics perform a 12-lead ECG?
  • Do you see anything that would suggest this patient is at-risk of anything life-threatening?
  • Is it okay for the parents to refuse transport to the emergency department?

Paramedics asked about the family history because early, unexplained deaths in the family could suggest some kind of inhereted disorder like Prolonged QT Syndrome, Wolff Parkinson White Syndrome, Brugada Syndrome or Hypertrophic Cardiomyopathy.

The fact that the father's brother died at age 16 is important (and would be even if the patient hadn't experienced a syncopal eposide).

Paramedics performed a 12-lead ECG because they knew the parents did not want their daughter transported to the hospital but they saw it as an opportunity to screen the patient for these disorders.

Now, some of you may think this kind of screening is dangerous or poses liability to the paramedics or EMS system because the paramedics haven't been formally trained in how to detect these abnormalities.

However, there's one easy rule you can follow to make sure you always do the right thing in EMS.

Treat every patient like a member of your own family.

A member that you like (preferrably).

I think we all understand (or at least I hope we all understand) that paramedics are not board certified emergency physicians, let alone pediatric cardiologists or electrophysiologists.

So, part of the risk of refusing care for any patient is that a paramedic's assessment is not equivalent to a qualified physician's assessment (complete with all the diagnostic tests they have at their disposal).

Let's break down these abnormalities one at a time.

  • Is the QT/QTc prolonged? No. 
  • Are there delta waves suggestive of WPW? No.
  • Is there a Brugada pattern? No.
  • Is it suspicious for HOCM? It's close to meeting the voltage criteria for LVH (for adults) in the precordial leads. But no.

If you saw the recent case on Burned-Out Medic's blog then you know the most difficult ECG-diagnosis in all of medicine is "Normal ECG"! 

However, one of the really cool things about Web 2.0 and blogging is "peer sourcing" and I do my best to make sure I'm giving out correct information.

So, I had this ECG reviewed by two people I respect a whole heck of a lot.

The first is Stephen Smith, M.D. from Dr. Smith's ECG Blog. Here's what he had to say.

It looks pretty normal to me. I get a QTc of 460 at most, not dangerous. Also, the history strongly suggests vasovagal.

Then, when specifically questioned about the voltage in the precordial leads:

I did notice that there is more voltage than usual, and thought about HOCM, but it is certainly not highly suggestive of it. And the patient was not exercising when this happened, and she had a classic vasovagal from looking at blood. I wouldn’t worry about it. On the other hand, if you sent her to the right ED (like ours) we would do a bedside ultrasound to look for LVH and septal hypertrophy. If you sent her to one that doesn’t do that, she would be sent home without any further workup (most likely) or possibly be admitted, and possibly get a formal echo at some point. It’s just playing the odds, and the odds of this kid having something bad are not zero, but they are very low.

I also had the case reviewed by Mark P. of the Electrophysiology Fellow blog. Here's what he had to say.

The ECG is normal. History is classic for vasovagal. The dead 16 year old necessitates followup for the extended family in any case (ECG as a first procedure). But there is no danger in this young girl not going to hospital. Reading the comments, almost all of the ECG changes noted by people are related to her age.

As a closing thought, some paramedics are quick to say that ECG transmission means that an EMS system doesn't trust its paramedics, and over and over again I've suggested that simply isn't true. There is nothing wrong with getting a second (or third) set of critical eyes on a 12-lead ECG, especially when the stakes are high (as they are for a possible STEMI patient).

There's no shame in transmitting an ECG like this to the hospital to get a second opinion (or even a first opinion if, like so many other paramedics, you have never been trained to look for prolonged QT, WPW, Brugada or HOCM). Discussing this case with Medical Control (as suggested by Ken Grauer, M.D. in the comments) is a great idea!

If you had a 13 year old daughter, sister or niece, how would you want the case to be handled by EMS?

Posted by on June 30, 2011 • Filed under: ems-topics, patient-management • Tagged: , , , , , , , , , , ,

Discussion to 63 year old male: chest pain – Wellens’ Syndrome? Or something else…

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This is the discussion for 63 year old male: Chest Pain.

Many of you thought the original 12 leads showed Wellens' Syndrome. 

Lets review some key points about the T wave inversions of Wellens' for a moment:

  • They occur when an occluded artery is reperfused, spontaneously or otherwise
  • They are always recorded during a pain free period
  • They are most prominent in V2-V4, rarely extending out to V6
  • QTc is usually greater than 425
  • T wave in III is usually upright

Let's take a look at the 12 Lead:

Initially, I also thought this was Wellens'.  I decided to seek the opinion of Stephen Smith, M.D. of  Dr. Smith's ECG Blog, and with his permission, here's what he had to say:  

"I don't think this is Wellens'. I think it is benign T-wave inversion. QT on the short side, distinct J-waves, extension out to V5-V6. It is a baseline of benign TWI followed by LAD occlusion."  Indeed, the QTc in the first two 12 leads were 422 and 418 respectively.  In his experience, the QT is prolonged in Wellens', and this is one way to differentiate it from benign T wave inversion (BTWI), which normally has a QTc < 400-425."

Now for the obvious STEMI:

Due to the deterioration of the patient's condition upon arrival to the hospital, he was brought directly to the acute area. Through translators, they were able to explain that patient was working out earlier this morning and developed right shoulder pain, which prompted the first EMS response. His symptoms resolved by EMS' first arrival and he sent them away. He subsequently took a shower and again began to feel the right shoulder pain, shortness of breath and lightheadedness again, which prompted him to recall EMS.  

A hospital ECG at 10:01 revealed improvement in patient's ST elevation (no copy was retained). Heparin was administered, and the patient was moved to the cath lab. The angiogram revealed single vessel coronary artery disease. The mid LAD had 95% acute plaque disruption. A thrombectomy was performed, and a white and pink thrombus was retrieved. The artery was stented, and TIMI-3 flow was restored.  Door-to-Balloon time was 34 minutes.

Here are the before-and-after angiograms:

Posted by on June 28, 2011 • Filed under: ems-topics, patient-management • Tagged: , , , , , , ,

13 year old female CC: Syncope

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EMS is called to a local hardware store for a 13 year old female with a possible seizure.

On arrival the patient is found sitting outside at a picnic table. Her mother and father are both present. The ambient temperature is hot and humid.

The patient's skin is very warm and moist but chalky. Her cheeks are pink which may be attributable to sunburn.

The patient's mother explains that the patient's sister had fallen off her bike and skinned her knee. The patient looked at the wound and fainted. She has fainted at the sight of blood before.

Neither the mother nor the father are interested in having their daughter transported to the hospital. A third party contacted 9-1-1.

They do, however, consent to an exam by EMS.

The patient is awake, alert, conversant, and oriented to person, place time and event.

Speach is clear and appropriate.

Equal smile, no arm drift, equal grip strengh, no pass pointing.

  • Past medical history: Healthy
  • Medications: None.

When questioned about family history (specifically about any history of a relative passing away unexpectedly from sudden cardiac arrest) the patient's father states that his brother died of a cardiac arrest at the age of 16.

When asked for specifics he states, "Some kind of seizure disorder. I was young."

Vital signs are assessed.

  • RR: 20
  • Pulse: 84
  • BP: 114/59
  • SpO2: 99 on RA
  • Temp: 99.1

The cardiac monitor is attached.

A 12-lead ECG is obtained.

The patient's skin color is now improved and she states she feels "fine".

Questions:

1.) Why did the paramedics ask questions about the family history?

2.) Why did the paramedics perform a 12-lead ECG?

3.) Do you see anything that would suggest this patient is at-risk of anything life-threatening?

4.) Is it okay for the parents to refuse transport to the emergency department?

See also:

13 year old female CC: Syncope – Discussion

Posted by on June 27, 2011 • Filed under: ems-topics, patient-management • Tagged: , , , , , , , , , , ,

64 year old male CC: Indigestion

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One of our faithful readers, Nicholas Eisele, sent in this interesting case study. As always, changes have been made to protect patient confidentiality.

After a long night of car wrecks, you get dispatched right before shift change on a Sick Person call.

As you arrive, your partner states she may have been here once or twice, usually for chest pain. A woman is waiting for you outside.

You meet the patient's wife on the porch and she leads you inside to her husband, sitting in a recliner, holding his chest. He appears to be in mild distress with moist, pale skin. As you kneel beside him to begin your assessment he speaks up.

"I said don't call the ambulance, it is just indigestion."

Deftly you obtain a history while your partner grabs a set of vitals.

  • Bypass x 5
  • Stent placement, "last Christmas"
  • Hypertension
  • Hypercholesterolemia
  • Type 2 Diabetes

You nod your head while the patient explains his reluctance, "to miss a good tee time this morning". You coax a medication list from him as well.

  • Lisinopril
  • Metoprolol
  • Metformin
  • NitroTabs

His wife adds that he was up all night and vomited more than once. She also informs you he has, "serious morphine and PCN allergies."

Your partner taps you on the leg before she quickly runs down the vitals.

  • Weak radials, "barely palpable"
  • Pulse: 80, regular
  • BP: 88/46
  • RR: 24
  • SaO2: 95% on room air

The cardiac monitor is attached.

The patient remains adamant that he does not need to go to the hospital. However, he consents to a 12-Lead ECG.

Due to his diaphoresis, it takes multiple attempts to acquire a readable ECG.

What is the rhythm?

What does the 12-Lead show?

Should this patient be allowed to refuse?

Posted by on June 25, 2011 • Filed under: ems-topics, patient-management • Tagged: , , , , ,

Discussion to 60 year old male CC: “I don’t feel well”

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This is the discussion for 60 year old male CC: "I don't feel well".

Go back and familiarize yourself with the history and clinical presentation because it's important to the case (as it always is).

Here is the rhythm strip and 12-lead ECG that was presented.

You may recall from my series on ineffective or inappropriate ICD shocks rhythm analysis for patients with an implantable cardioverter-defibrillator can be challenging.

That's because patients with sick hearts often suffer from both atrial fibrillation and bundle branch blocks which predisposes them to "wide and fast" rhythms.

If you've taken nothing else away from the EMS 12-Lead blog I hope you've taken away the message that "wide and fast" is VT until proven otherwise! 

Granted, irregular wide and fast rhythms are a special case. In the first place you avoid adenosine according to the 2010 AHA ECC Guidelines. That's because atrial fibrillation is unlikely to respond to adenosine, not to mention that giving adenosine to a patient with WPW and atrial fibrillation can precipitate VF.

So let's look at the differential diagnosis of the wide complex tachycaria.

Could it be VT?

Sure. It's rare for VT to be irregular but it's certainly not impossible. We need to remember that the patient has received an ICD so one assumes the patient is at high risk for malignant ventricular arrhythmias. "But the axis is normal!" you might say. Yes, but as I've mentioned so many times before, it's an EMS myth that VT always shows an extreme axis deviation. In fact, LBBB in lead V1 with a normal frontal plane axis is normal for VT orignating in the right ventricular outflow tract.

Could it be AF with LBBB and RVR?

Yes. This is entirely possible. Quite often irregular wide complex tachycardias turn out to be AF with RBBB, LBBB, or nonspecific IVCD. It's a bit unusual but certainly not impossible for LBBB to show a normal frontal plane axis.

So, if it could be either VT or "SVT" (a term I don't care for) with aberrancy (or preexisting bundle branch block) then how should we treat the patient? Should we treat the patient at all?

When faced with a situation like this I think it's far more important to "risk stratify" the tachycardia rather than "diagnose" it. In other words, remember the first rule of medicine: "Do No Harm!"

Above all else, avoid IV medications that could kill the patient if it turns out to be VT.

So why isn't the ICD shocking? Because the rate isn't fast enough. It's not unusual at all for patients with an ICD to present with a wide complex tachycardia below the rate limit that initiates cardioversion or defibrillation.

So what else happened in this case?

En route to the hospital an additional 12-lead ECG was captured and several more rhythm strips.

This 12-lead ECG reveals an important problem with prehospital 12-lead ECGs. They often crop the S-wave, especially in the right precordial leads (V1-V3) which can makes it impossible to compare the ST-segments to the depth of the S-waves (rule of proportionality).

The patient was delivered to the emergency department where the following 12-lead ECG was taken.

Now we can see the depth of the S-waves in leads V1-V3 and there's a problem (beyond the fact that the precordial leads have been placed differently on the patient's chest).

If this is a left bundle branch block then excessively discordant ST-elevation is present in leads V2 and V3 which indicates acute STEMI.

So what was the outcome?

All we know for certain is that the patient received successful synchronized cardioversion in the emergency department. The paramedic who submitted the case was told by the RN in the emergency department that the QRS complexes were narrow after the cardioversion (which would support a ventricular origin). However, we don't have a post-cardioversion 12-lead ECG to confirm.

We also don't know whether or not the patient ruled-in for AMI. But I certainly wouldn't be surprised! 

Posted by on June 24, 2011 • Filed under: ems-topics, patient-management • Tagged: , , , , , , , , , , ,

New device allows you to assess BP with iPhone

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h/t Ubergizmo

A new device by Withings will allow you to plug a BP cuff directly into an iPhone, iTouch or iPad. This could be very good for millions of people in the world who suffer from high blood pressure.

See YouTube video HERE.

We recently reported on the iCard ECG that will allow patients to monitor their own electrocardiogram with an iPhone, iTouch, iPad, Droid or Tablet. 

See YouTube video HERE.

Other devices like the iBGStar turn the iPhone into a blood glucose monitor. 

See video HERE.

 

You could imagine a scenario where a physician (or other health care provider) could work in a very remote region of the World and assess blood pressure, an electrocardiogram and blood glucose with a very small kit.

It also seems obvious that people with a history of high blood pressure, heart rhythm disorders and diabetes will be able to track their medical condition much more effectively and without much regard to location.

We're on the verge of a new era of mobile health (also referred to as mHealth).

The Wikipedia defines mHealth this way:

mHealth (also written as m-health or mobile health) is a term used for the practice of medical and public health, supported by mobile devices. The term is most commonly used in reference to using mobile communication devices, such as mobile phones and PDAs, for health services and information. The mHealth field has emerged as a sub-segment of eHealth, the use of information and communication technology (ICT), such as computers, mobile phones, communications satellite, patient monitors, etc., for health services and information. mHealth applications include the use of mobile devices in collecting community and clinical health data, delivery of healthcare information to practitioners, researchers, and patients, real-time monitoring of patient vital signs, and direct provision of care (via mobile telemedicine).

There's a lot of hype out there with regard to mobile health and many of the apps are completely delusional. However, apps that convert smartphones into medical devices are, in my view, simply awesome! 

Keep up with the latest trends in mHealth by following the mHealth page on Facebook and the Wireless Health group at LinkedIn.

Posted by on June 21, 2011 • Filed under: ems-topics, patient-management • Tagged: , , , , ,

63 year old male: chest pain

11 comments

David here, posting my first case on the blog… hope you enjoy, and Happy Father's Day! Here's an interesting case submitted by "Mike from Mass".  Some minor details have been changed to preserve patient confidentiality.

EMS is dispatched to a residence for a 63 year old male with chest pain. Dispatch advises that a different crew had responded about 30 minutes earlier, but the patient refused transport against medical advice.

Upon arrival, the crew finds a 63 year old male walking towards them, in no apparent distress. There is a moderate language barrier, but the the crew is able to understand that the patient began experiencing right back pain while taking a shower about an hour ago. He may also have experienced shortness of breath and chest discomfort, but the crew is less certain of this due to the language barrier.  Patient is alert and oriented X 4, with clear lung sounds.  The crew obtains the following vital signs:

  • BP: 142/70
  • HR: 52 bpm, regular
  • RR: 14
  • SpO2: 98%
  • BGL: 137

While trying to obtain the patient's medical history, the crew learns that the patient has not received regular medical care until one year ago. The patient is able to deny any allergies, but regular medications and any past medical history are unclear. The patient is given 324 mg baby ASA, but nitrates are withheld due to unclear PDE5 inhibitor (ED drugs) status. Prior to transport to a PCI capable hospital, IV access is established and  the following 12 lead is acquired:

Enroute, another 12 lead is acquired:

Upon arriving at the hospital, the patient becomes acutely anxious and tremulous.  The crew observes that the patient now appears to be in moderate discomfort, with a rising heart rate. A third 12 lead is acquired by the crew:

What do you think is going on?

What do you think about the change in the patient's presentation?

How would you treat this patient?

 

Posted by on June 19, 2011 • Filed under: ems-topics, patient-management • Tagged: , , ,

AliveCor’s iCard ECG for iPhone 3G, iPad and Android

9 comments

You may recall my previous reporting on the incredible iPhonECG (subsequently re-named the iPhone ECG) which caused quite a stir in the medical and gadget blogosphere.

It's the third-most visited page in the history of the EMS 12-Lead blog (behind the lead placement charts and the notice that the 572 pound spokesman for the Heart Attack Grill died of a sudden cardiac arrest).

The original invention was a simple cell phone case that turned the iPhone 4 into a clinical quality ECG monitor. The ECG is stored locally on the smart phone and can be transmitted anywhere in the world.

Incredibly, the device can capture a high-quality ECG through a cotton t-shirt!

What paramedic or nurse wouldn't want one of those?

That's not to say there aren't any naysayers. A small handful either can't see the potential or have some doubts.

I gave this explanation of a possible use for the iPhone ECG in a discussion on the Wirelss Health group on LinkedIn.

Consider this scenario. An acute care NP is having dinner with her husband and they notice a commotion in the corner of the restaurant. Someone is "down". She comes over and and assesses the patient. His pulse is slow and weak. Out comes the iPhonECG and she captures third degree AV block. By the time EMS arrives the arrhythmia has resolved. She says to the paramedics, "Here's my phone number. Have the ED physician call me and I'll transmit the ECG for the patient's medical record." Now, instead of being blown off as "vaso-vagal syncope" they know the patient has a significant conduction problem in his heart.

You could imagine dozens of other scenarios. Indeed, the iPhone ECG is an incredible device. I can't wait to get my hands on one! 

Dr. Dave Albert, the inventor of the iPhone ECG, recently gave this entertaining talk at TEDxOKC explaining how the iPhone ECG went "viral" on the internet.

Unfortunately, I no longer own an iPhone. I lost my iPhone 3G at Disney World last year and replaced it with a Droid X.

I'm generally happy with the Droid X, but the iPhone ECG is only for the iPhone. It would be too difficult to make it work for Android because Android isn't a phone, it's an operating system.

Dozens of different phones run on Android so AliveCor would have to design dozens of different cases to make this invention work with a Droid phone, let alone the Ipad or a Tablet. Right?

Wrong! 

In walks the iCard ECG!

With the iCard ECG any of these devices can be converted instantly into a clinical quality ECG monitor. I realize that Dr. Dave did not specifically mention Droid phones in the YouTube video for the iCard ECG but he did clarify the point on Twitter.

So, who else wants one?

As @scottthemedic posted on Twitter….

See also:

Universal iCard ECG attachment for your iPhone & iPad – The Rohan Aurora

iCard ECG Turns Any iPhone/iPad Into a Powerful Electrocardiograph – MedGadget

Posted by on June 17, 2011 • Filed under: ems-topics • Tagged: , , , , ,

60 year old male CC: “I don’t feel well”

49 comments

Here's an interesting case from an faithful reader who wishes to remain anonymous. Some changes have been made to help preserve patient confidentiality.

This is a 60 year old male, who activated EMS for not feeling well.

The call came in from a home way out in the county, and although it was dispatched as a low acuity sick call, the responding unit ran emergency traffic to the home.

On arrival, a BLS fire unit was on scene, triaging the patient green.

Report from the firefighter EMT was as follows: Patient contacted EMS for slight shortness of breath, we have him on 15 liters O2 NRB mask, he just had a pacemaker put in three days ago.

Patient is alert and oriented x4,

VS as follows:

  • BP-180/90
  • RR-28
  • O2 sat- 98% on non rebreather (RA sat was 92%)
  • Pulse- around 100

Patient contact reveals the patient sitting upright in his recliner, speaking in full sentences.

He states that she is absolutely not going to the hospital no matter what!

On further questioning, patient says he has been feeling a “funny feeling” in addition to a little shortness of breath for the past hour.

  • Onset of one hour
  • Exertion makes it worse  
  • Severity is a 2/10 
  • Was walking to the restroom when the funny feeling started 

It feels like its getting better as long as he stays still. He hasn’t taken any of his meds today.

Questioning of family members reveals that he received multiple prescriptions but hasn’t had them filled yet. He has been off all of his meds since he left the hospital two days ago.

They are unsure of all of the medications but know that they included:

  • Coumadin
  • Amiodarone
  • Lasix 

Patient has no drug allergies.

Hx of:

  • Diabetes
  • HTN
  • CAD
  • A-fib
  • Pacemaker/ICD placed three days ago

Ate a big meal last night

Bilateral breath sounds are clear and slightly diminished.

EMS crew convinces patient to go to the local hospital 20 minutes away just to get checked out.

Patient finally agrees but is adamant about walking to the truck or else he is not going.

During the trip to the truck, patient begins to experience severe dyspnea and says that he needs to sit down.

The patient sits down on the cot for transport to the unit. Audible rales are heard when the patient begins complaining of the severe dyspnea.

In the truck, patient is attached to the cardiac monitor and a 12 lead is performed.

What is the differential diagnosis for this heart rhythm?

What do you think is going on?

How would you treat this patient?

See also:

Discussion to 60 year old male CC: "I don't feel well"

Posted by on June 14, 2011 • Filed under: ems-topics, patient-management • Tagged: , , , , , , , , , , , ,

57 year old female CC: Shortness of breath and chest pressure – Discussion

8 comments

This is the discussion for 57 year old female CC: Shortness of breath and chest pressure.

Let's take another look at the 12-lead ECGs.

I posed the following questions for this case:

  • What do you think of these 12-lead ECGs?
  • What is the most likely cause of the ST-depression and T-wave inversion.

These ECGs show a "strain pattern" (or secondary repolarization abnormality) due to left ventricular hypertrophy which is one of the most common STEMI mimics.

A strain pattern often presents with significant ST-elevation in the right precordial leads (V1 – V3) which is the main reason that it can mimic acute anterior STEMI. Often the ST-elevation can be quite dramatic.

Consider this case from Dr. Smith's ECG Blog for an example.

Also consider this ECG from the 12 Lead EKG blog (with permission).

Here the ST-elevation in the right precordial leads (V1-V3) is impressive. However, the S-waves are very deep! This is the big tip-off that we're dealing with a STEMI mimic.

In this case the patient was cathed because he experienced a VF arrest while on the treadmill at cardiac rehab. You can't blame anyone for sending a patient like that to the cardiac cath lab! 

What they found was extensive coronary artery disease and chronically occluded vein grafts but no acute thrombosis in the LAD.

Interestingly, Stephen Smith, M.D. from Dr. Smith's ECG Blog has stated that he has only seen one or two LAD occlusions in his entire career that met the conventional LVH criteria in the right precordial leads! Why should this be?

He theorizes that perhaps acute STEMI attenuates the S-wave voltage in the right precordial leads in the setting of pre-existing LVH.

Interesting theory! 

Consider this ECG from the previous case of the 55 year old male with (possible) chest pain.

In this case the patient was cathed and ended up having a 100% chronic occlusion of the LAD. However, the T-waves do appear to be hyperacute in this ECG and there was a modest rise and fall of cardiac biomarkers.

We were unable to obtain an "old" ECG for comparison, but based on the appearance of lead V1 it certainly looks as if this ECG met the LVH criteria in the precordial leads prior to the development of pathological Q-waves in leads V2 and V3.

A "strain pattern" (evidenced by ST-depression and T-wave inversion) is still present in the high lateral leads (I and aVL).

Now let's get back to the case of the 57 year old female with shortness of breath and chest pressure.

Does it meet the voltage criteria for left ventricular hypertrophy?

Absolutely!

The S-wave depth measures 23 mm in lead V1 and 29 mm in lead V2! The R-wave amplitude measures 12 mm in lead V5 and 13 mm in lead V6. So, if we add the S-wave depth in lead V2 and the R-wave height in lead V6 we get 44 mm (cut-off is 35 mm) so this meets the most commonly used voltage criteria for LVH.

Here's how I'm measuring the S-waves (see comments).

Here's a close-up of the right precordials from another ECG that was submitted with the case study that I didn't publish earlier due to poor data quality in the limb leads. Here you can see the separation a little bit better.

Based on this I would expect a significant ST/T wave abnormality in the opposite direction! To me the most striking thing about this case is the absence of significant ST-elevation in leads V1 and V2.

Having said that, the ST-depression and T-wave inversion in leads with an upright QRS complex are almost certainly due to left ventricular hypertrophy.

Posted by on June 6, 2011 • Filed under: ems-topics, patient-management • Tagged: , , , , , , , , , ,

Conclusion to 60 year old male CC: Sudden cardiac arrest

1 comment

This is the conclusion to 60 year old male CC: Sudden cardiac arrest.

As you may recall the resuscitation was implemented using the choreographed or "pit crew" model.

This is characterized by:

  • Leadership
  • Skills and competencies
  • Teamwork and communication
  • Best practices
  • Rehearsal

Special emphasis is placed on:

  • Minimally interrupted chest compressions
  • Controlled ventilations
  • Defibrillation
  • Appropriate timing (e.g., pre-charging the defibrillator, shocking every 2 minutes, miminizing delays between stopping compressions and shocking)

This is not meant to miminize the importance of the chain-of-survival, including early activation of 9-1-1 and bystander CPR. Those links were intact for this case and that is extremely important.

As you might recall return of spontaneous circulation (ROSC) was achieved, the patient was loaded for transport, and a 12-lead ECG was captured.

Let's take another look.

The obvious question (and the one I usually ask) is whether or not this 12-lead ECG shows STEMI.

However, before we look at that, let's review some important comments from:

Regional Systems of Care for Out-of-Hospital Cardiac Arrest – A Policy Statement From the American Heart Association. Circulation 2010;121:709-729

Up to 71% of patients with cardiac arrest have coronary artery disease, and nearly half have an acute coronary occlusion. There is a high incidence (97%) of coronary artery disease in patients resuscitated from OOHCA who undergo immediate angiography and a 50% incidence of acute coronary occlusion. However, the absence of ST elevation on a surface 12-lead electrocardiogram after resuscitation of circulation from cardiac arrest is not strongly predictive of the absence of coronary occlusion on acute angiography (emphasis added). A case series of patients with unsuccessful field resuscitation suggested that in such patients, VF is more likely to be due to coronary disease than is asystole or pulseless electric activity. An autopsy study compared case subjects who died within 6 hours of symptom onset due to ischemic heart disease and who were not seen by a physician within 3 weeks with control subjects who died within 6 hours of symptom onset due to natural or unnatural noncardiac causes…Collectively, these studies suggest that patients who are resuscitated from out-of-hospital VF have a high likelihood of having an acute coronary occlusion (emphasis added).

The feasibility and efficacy of primary PCI in patients who survive cardiac arrest with STEMI have been well established. The combination of mild therapeutic hypothermia with primary PCI is feasible, may not delay time to start of primary PCI in well-organized hospitals, and is associated with a good 6-month survival rate and neurological outcome…Patients resuscitated from OOHCA with STEMI should undergo immediate angiography and receive PCI as needed. Immediate coronary angiography is reasonable for patients resuscitated from VF and may be considered in patients resuscitated from other initial rhythms who do not have a clear noncardiac cause of cardiac arrest (emphasis added).

Does the first 12-lead ECG look like it might be an acute anterior STEMI? I would have to say yes (the 12-lead ECG captured on arrival at the hospital does not look like a classical STEMI — we'll get to that in a minute). However, my question for you is, should it matter?

The patient has been resuscitated from sudden cardiac arrest of presumed cardiac etiology. That alone is enough reason to send the patient emergenty to the cardiac cath lab, IMHO. That (along with other important post-resuscitation care like therapeutic hypothermia and ICDs) is why the AHA is advocating regional systems of care for out-of-hospital cardiac arrest.

Now let's look at the 12-lead ECG acquired on arrival at the hospital.

Now rather than ST-elevation in the anterior leads we see a different ECG abnormality that is also concerning. Namely, ST-elevation in lead aVR and V1 with ST-depression in leads I, II, III, aVL, aVF, V3, V4, V5 and V6.

(Side note: remember the "rule of proportionality" when you look at ST-elevation or ST-depression. The QRS complexes in the limb leads are very small. Hence, even a tiny bit of ST-elevation or ST-depression is significant).

This could indicate left main coronary occlusion, 3-vessel disease, or subendocardial ischemia. Again, this is just academic since you could argue that all patients resuscitated from VF arrrest should be emergently cathed.

On arrival at the hospital the attending ED physician grabbed the Code Summary out of the treating paramedic's hand and saw this rhythm strip.

As a happy coincidence this rhythm strip (which was captured in monitor mode) exaggerated the ST-elevation in lead V1. Perhaps the ED physician would have called the Code STEMI anyway. At any rate, the Code STEMI was called immediately.

Angiography revealed severe atherosclerotic disease that was not amenable to catheterization. The patient was taken emergently to the OR where he received a 5-vessel CABG.

The patient was discharged from the hospital a week later neurologically intact.

Posted by on June 3, 2011 • Filed under: ems-topics, patient-management • Tagged: , , , , , , , , , , , ,