82 yom CC: chest pain

Here's an interesting case I pulled off the LIFENET Receiving Station.

Update: ECGs were retrieved from the archives of the LP12 for better data quality.

82 year old male complaining of chest pain.

PMH: HTN, including pulmonary hypertension

Meds: Unknown antihypertensives, ASA

Vital signs:

Resp: 20
Pulse: 60
BP: 120/73
SpO2: 96 on RA

Breath sounds: clear

Skin is cool, pale, and diaphoretic. The patient admits to mild dyspnea. He also admits to slight nausea but he has not vomited. He describes his pain as pressure and 6/10 in severity.

The cardiac monitor is attached.


A 12 lead ECG is obtained.


What is your interpretation of this ECG?

Update: Here is the 12 lead ECG obtained on arrival at the ED.

Do you see why serial 12 lead ECGs are important?

Agonal breathing predicts survival from cardiac arrest

A recent report by heartwire gives an overview of:

Bobrow BJ, Zuercher M, Ewy GA, et al., Gasping during cardiac arrest in humans is frequent and associated with improved survival. Circulation. Published online before print November 24, 2008.


Among the highlights:

Someone stricken with out-of-hospital cardiac arrest might still be gasping for air, but that's no reason for witnesses to avoid jumping in with chest compressions, according to researchers who studied the phenomenon. On the contrary, that initial period of distressed breathing might last only minutes but provides the best chance for resuscitation efforts to succeed and allow the patient to survive to hospital discharge.

According to coauthor Dr Gordon A Ewy (University of Arizona Sarver Heart Center):

The gasping is a sign of poor but marginally adequate cerebral perfusion, and it is promising whether it starts as the patient collapses or only after the beginning of CPR [...] Lay people who initiate CPR tend to be startled if gasping occurs, believing the patient is 'waking up,' and then often stop what they are doing [...] but, 'gasping is an indication that you're doing a great job and you shouldn't stop.'

The article goes on to explain:

Ewy is among the principal advocates of what he calls cardiocerebral resuscitation for arrest of cardiac origin, characterized most notably by an emphasis on chest compressions uninterrupted by assisted breathing. The technique [...] was recently endorsed by the American Heart Association as being about as effective as the traditional method involving compressions plus "mouth to mouth" resuscitation.

But proponents of the chest-compression-only method say it is superior, not only in being more successful but in encouraging bystanders to attempt it in the first place. In fact, Ewy said, the current study was designed, in part, to help get the public and providers to see abnormal breathing as a reason to initiate or continue CPR rather than a reason to stop or avoid it.

See also:

The case for continuous chest compressions

Paramedics save more lives when they don't follow the rules

Prehospital Advanced Airway - Should Paramedics Be Intubating?

It's a shame that so little attention was paid to the 2003 ACLS Reference Textbook and Experienced Provider Manual. Part of the problem was the delayed release. By the time it finally came out, everyone knew the 2005 update was around the corner, so why incur the expense? In my opinion, it was the best set of ACLS books the AHA has ever published.

One of the best things about the ACLS Reference Textbook is Chapter 8 - Airway, Airway Adjuncts, Oxygenation, and Ventilation. I wish it was required reading for every paramedic in the United States. It would save a lot of time, because we spend entirely too much time rehashing the same ground in the debate about prehospital tracheal intubation.

Here are some highlights:

The ECC Guidelines 2000 emphasize the need for training of healthcare providers in bag-mask ventilation [...] This emphasis on use of bag-mask ventilation should reduce the perceived need for urgent insertion of advanced airways [...] Bag-mask ventilation can prevent the potential deleterious consequences of attempted intubation by inexperienced providers and complications of undetected tube misplacement or displacement [...] The emphasis on bag-mask ventilation is particularly useful for caregivers working in out-of-hospital settings where opportunities for experience in intubation are extermely limited. This emphasis is especially appropriate when transport times are short (Class IIa).

Tracheal intubation, once the "gold standard" of assisted ventilation, remains the advanced airway of choice only for experienced providers who working in programs with careful performance monitoring, defined requirements for skills maintenance (e.g., establishment of minimal number of intubations to be accomplished per year), and an atmosphere of continuing quality improvement [...] In the absence of quality improvement programs, the probability of lethal complications from tracheal intubation become unacceptably high.

See also:

2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care - Part 7.1: Adjuncts for Airway Control and Ventilation

Does your EMS system observe careful performance monitoring?

Do you QA/QI every intubation attempt?

Is there a defined requirement for skills maintenance?

Do you rotate through the OR if necessary?

Are you breathing in the sweet atmosphere of continuing quality improvement?

If so, then you are in that minority of paramedics that has any business attempting tracheal intubation in the prehospital setting.

Unfortunately, there is still a tremendous amount of denial on the part of paramedics in EMS systems all over the country. I'm not talking about King County Medic One, Austin-Travis County EMS, Hennepin County EMS, Wake County EMS, Boston EMS, Miami-Dade Fire Rescue, or any of the other EMS systems that meet the above captioned criteria. I'm talking about the ones that don't. In other words, the vast majority of EMS systems in the country.

The first step is to admit you have a problem.

It is no longer enough to claim you don't have a problem. It must be demonstrated. Why? Because tracheal intubation is a difficult and dangerous invasive procedure that kills patients when it is performed poorly. You need to demonstrate that you have the psychomotor skills to intubate, and the patient assessment skills to maintain the tube once it is properly placed. In addition, you should be able to demonstrate that your patients do better with intubation than without it.

A recent podcast at EMS Garage did a fantastic job of presenting both sides of the debate. (Fast forward to 26:05). I especially approved of a couple of comments made by Skip Kirkwood (Chief of Wake County EMS). Here are some exerpts from an exchange he had with another guest on the program (I think it was Will Dunn but I'm not certain. If someone knows for sure, please send me an email.)

Skip Kirkwood:

"I will tell you that based on the data that in our service the medics themselves are using the King airway as the airway of choice in cardiac arrest 80% of the time because they can have the airway in and the patient ventilated in the time that it takes to unfold the laryngoscope and put air in the syringe for the ET tube. Of choice; not of mandate, and not throwing the laryngocope and ET tubes off the ambulance. Same thing -- low and behold -- in cardiac arrest with IV access. You come to our system and run the next 25 cardiac arrests and if you see somebody with a catheter in their hand, you'll be with somebody who's probably a very tenured paramedic, because the rest of the folks will have two EZ-IOs in before you can unwrap the manual catheter. So, when you said you think it's an inferior airway method, our belief is that the data shows to the contrary; that patients who get a King airway have better outcomes, and our data shows that."

Other guest:

"Why wouldn't you intubate? [...] If all things are equal, and I'm not saying that they are, but if all things are equal, isn't an endotracheal tube the gold standard? [...] it seems to me that the King doesn't necessary protect the airway in certain situations where the endotracheal tube does. So, that's what I'm struggling with, and I think there's technology out there [...] where we can increase our success rates with intubation rather than thow it away like we did with the MAST pants."

Skip Kirkwood:

"[W]e shouldn't throw [tracheal intubation] away [...] I'm an old guy, I was very proud of being able to drop ET tubes at the drop of a hat, but we're not tubing as many people anymore, so the opportunity to gain that proficiency is not there, our protocols have changed so we're not getting an airway immediately, it's not the first thing we do in a cardiac arrest -- we compress and we defibrillate -- and so I don't feel a need to save [tracheal intubation] because there's just kind of no reason to. In a very high percentage of patients we can control an airway with kind of a "wham bam thank you sir, here's your airway" without having to put up with all the stuff that is involved in endotracheal intubation particularly after CPR has been done for a while."

Other guest:

"I hate to see something that I think is a valuable tool in airway management, whether you're convinced it's the end-all-be-all or not, go by the wayside when I think for a long time, it's kind of what defined us as paramedics was our ability to manage the airway."

Skip Kirkwood:

"I think that's true, and I hate to say this, but shame on us, because we are the only health care provider group that defines ourself by what we can do that's unique rather than what good we do the patients."

Other guest:

"But in a cardiac arrest, if it's your loved one, and you're there, and you've got a King and an ET tube, and you've been doing this for 20 years...?"

Skip Kirkwood:

"If it's me or my loved one, I will pray that you will put that King airway down, because you can do so in two seconds, without interrupting compressions, and uninterrupted compressions are now the gold standard for saving people in cardiac arrest."

That, ladies and gentlemen, is enlightened leadership.

Computerized interpretive statements and bundle branch blocks

Here's an ECG that I've used in my 12 lead class for many years. It's usually good for a laugh!

I show this ECG right after I teach students to identify LBBB on the 12 lead ECG.

I explain that it was captured on an emergency call for a 80 year old male who was out jogging when he became acutely ill. EMS finds the man sitting down on a bike path. He is alert and oriented to person, place, time, and event; but he's cool, pale, and diaphoretic with absent radial pulses. He states to the EMS crew that he has a history of high blood pressure. His medications include Norvasc, a daily aspirin, and a statin.

At this point I ask them to identify the heart rhythm.

No one speaks up right away. No one wants to look stupid in front of the class (one of the things you find out about adult learners).

Finally, I prompt them.

Do you see any P waves?

"No," they all say in unison.

Is it regular or irregular?

"It's regular."

What's the rate?

Someone says, "32."

So what is it?

"Junctional."

Hmmm........

Are the QRS complexes wide or narrow?

"Wide."

So what is it?

"Junctional with left bundle branch block."

Before you learned how to read a 12 lead ECG and identify LBBB, what did you call slow, regular rhythms without P waves and wide QRS complexes?

"Idioventricular rhythm."

Okay.... so what's changed?

My point is simple. Wide complex rhythms are ventricular until proven otherwise. Granted, this rule of thumb is typically used for rhythms that are wide and fast. However, the rule is equally valid for rhythms that are wide and slow!

"But the computerized message at the top says it's a left bundle branch block."

Yes, it does. It also says "undetermined rhythm."

The computer is saying, "I don't know what rhythm this is, but the morphology matches LBBB."

Is it possible that this rhythm is junctional with LBBB? Yes! It's possible. But do you assume that it's junctional? No. You assume the worst. You assume that it's an idioventricular rhythm.

Then I pose a challenge to the class. Is there an experiment you could perform to help determine if the rhythm is junctional or ventricular? What I'm looking for is a student to say, "Well, you could try o.5 mg Atropine."

If the rhythm responds to Atropine, there's a good chance it isn't ventricular. If it doesn't respond to Atropine, it really doesn't prove anything.

A few years back I asked my hypothetical question, and a hand went up in the back of the class (that should have been my first clue that I was dealing with a trouble-maker). I was really hoping he was going to suggest 0.5 mg Atropine. So I called on him.

With a dead-pan look on his face he says, "If the Lidocaine kills him, it was ventricular."

Touché.

Transcutaneous Pacing (TCP) - The Problem of False Capture

2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care - Part 7.3: Management of Symptomatic Bradycardia and Tachycardia:

"If bradycardia produces signs and symptoms (eg, acute altered mental status, ongoing severe ischemic chest pain, congestive heart failure, hypotension, or other signs of shock) that persist despite adequate airway and breathing, prepare to provide pacing. For symptomatic high degree (second degree or third degree) atrioventricular (AV) block, provide transcutaneous pacing without delay."

Transcutaneous pacing (TCP) is perhaps the most underutilized and misunderstood Class I intervention in all of ACLS. Why? Simple. Because it's impossible to simulate during training.

Be honest. In paramedic school, when you went through the bradycardia station, and you were given a scenario with a patient who was experiencing a hemodynamically unstable bradycardia, what happened when you told the instructor that you wanted to immediately attempt transcutaneous pacing?

If you're like hundreds of other paramedic students all over the country (and for all I know, the world) you were told "the pacer is broken." That was your cue to say, "Okay, then I'd give 0.5 mg Atropine rapid IV push." Never mind that the rhythm might have been 3rd degree AV block with wide complexes (for which Atropine is not indicated).

Is it any wonder that so many paramedics (and to be fair, other health care providers) perform this skill poorly or not at all?

Let's look at a case study.

This was an elderly male that the treating paramedic found supine on the floor with an altered level of consciousness. Radial pulses were present, but slow and irregular. The cardiac monitor was attached and the following ECG was obtained.


I don't remember any other details about the history or clinical presentation, but it's irrelevant to the central point of this case study.

The treating paramedic elected to perform immediate transcutaneous pacing (TCP). The combopads were attached and the pacer was turned on.

As you can see in the ECG strip below, the computer began tracking QRS complexes and the pacer was set for 60 PPM.


I would also like to point out that this particular LP12's pacer had a default setting of "non-demand mode". This is somewhat unusual, but it turns out to be the key to solving this case.

The treating paramedic increased the current to 40 mA.


60 mA.


90 mA


At this point, the paramedic reported radial pulses that corresponded to the pacer and an improved level of consciousness. The rate was changed from 60 to 70 PPM.


Does the paramedic have capture? Be honest! It looks like it, right?

Unfortunately, no. The paramedic does not have capture.

Then what in the Wide World of Sports are the QRS complexes after the pacer spikes?

The answer is that the monitor is showing "phantom" QRS complexes or "false capture".

Don't believe it? Let me prove it to you.

Here is the same rhythm strip. The underlying rhythm appears to be junctional at approximately 40 beats/min.


In the next strip, you can see the underlying rhythm marching through the absolute refractory period of a (presumed to be) paced QRS complex. That's not scientifically possible!


In the next strip, you can see a (presumed to be) paced QRS complex in the absolute refractory period of a QRS complex from the underlying rhythm. That's also impossible!


Finally, you will notice that the SpO2 monitor is counting the pulse rate at 42 BPM, not 70 BPM.


Whatever these complexes are that follow the pacer spikes, they do not represent ventricular depolarization.

So what are they?

Artifact.

What kind of artifact?

Electrical artifact.

Let's look at a side-by-side comparison of the "phantom" QRS complexes as the current was dialed up.


As you can see, the QRS complexes look essentially the same (QS complexes with an almost vertical downstroke and slightly curved upstroke back to the isoelectric line, non-distinct ST segment and a virtually absent T wave). The only difference is the size. As the current was dialed up, the complexes got larger.

As you can see in the following graph, there's an almost linear relationship between the amount of current and the amplitude (or depth) of the "phantom" QRS complexes.


Where does this electrical artifact come from? Why didn't anyone tell us it would be there?

Good questions!

I discussed this case at length with a Sr. Clinical Specialist from Medtronic Physio-Control. He told me that the LP12 essentially closes its eyes for approximately 40 ms (one small block) after each pacer spike (a pacer spike is nothing more than a graphic representation that an electrical current is about to be sent between the combopads).

To understand why the LP12 "closes its eyes" when it delivers an electrical impulse, you need only ask yourself one simple question. What does an ECG monitor measure?

Electrical activity!

If it didn't "close its eyes" so to speak, the ECG recording would go right off the paper! So the idea is that the monitor closes its eyes while the current is delivered, and then "opens them" in time to see the QRS complex it creates.

Do you see where this is going?

If the monitor "opens its eyes" too soon, the electrical signal has not yet returned to baseline. The result is a "phantom" QRS complex on the ECG.

It certainly doesn't help that the ACLS textbook has shown the exact same rhythm strips for transcutaneous pacing for as long as I've been a paramedic!

Let's take a look.


The first strip shows sinus bradycardia. The second strip shows sinus bradycardia and pacer spikes without capture. The third strip shows a beautiful paced rhythm!

Ta-da!

If only it was this simple in the real world!

I know what you're thinking. Why did the paramedic report pulses that corresponded with the pacer?

Think about it!

The patient has an underlying rhythm, so some pulse waves are going to be felt. In addition, do not underestimate the combination of skeletal muscle twitching and wishful thinking! You are being visually stimulated with every pacer spike, and it's impressive!

Ever heard of cough-CPR? I am convinced that the contraction of pectoral muslces, intracostal muslces, and other intrathoracic structures produces some type of arterial pulse wave.

But you said the paramedic also reported an improved level of consciousness!

That's true, but something tells me you'd be more alert, too, if someone started to shock you once a second for a couple of minutes! Your blood pressure might even go up.

Here are some clinical pearls to get you through the procedure.

• The most common cause of failure with transcutaneous pacing (TCP) is poor pad placement combined with insufficient milliamperes! Remember, the pacer goes up to 200 mA! If you lose your nerve at between 70-90 mA, there's a good chance you're not going to achieve capture. Consider anterior/posterior pad placement to "sandwich" the left ventricle between the pads and reduce transthoracic resistance.

• Look for a tall, broad T wave that is the telltale sign of true electrical capture.

• Perform, but do not rely solely on a manual pulse check. Consider using an instrument like an SpO2 monitor, doppler, or bedside 2D echo (for inhospital patients) to verify mechanical capture.

• Run a continuous rhythm strip that shows the transition from "false" capture to true electrical capture. Be able to document the exact milliamperes that capture is gained, and capture is lost. (Note: one of the "quirks" of the human heart is that once you gain capture it is harder to lose. In other words, you might achieve capture at 120 mA, but then you might have to dial it back down to 80 mA to lose it again). Many protocols state that you should add 10 mA as a "safety margin" once capture is achieved. In my experience this is unnecessary for the reason stated.

• Finally, you can consider placing the pacer in "non-demand" mode and examine the absolute refractory periods of the underlying rhythm and the (presumed to be) paced rhythm. If the paced rhythm and the underlying rhythm are marching through each others' absolute refractory periods, you don't have true electrical capture.

See also:

Pacing Artifact May Masquerade as Capture (Phsyio-Control website)

Large block method for heart rate calculation

I've noticed that some paramedics are not proficient at estimating the heart rate using the large block method for heart rate calculation. This is unfortunate. I realize that modern ECG machines calculate the heart rate, but I my attitude toward machines is similar to Ronald Reagan's attitude toward the Soviet Union. "Trust but verify."

I created the following image using nothing but PowerPoint.


You only have to remember 6 numbers. 50, 60, 75, 100, 150, and 300.

Or, if it helps you to remember it fast-to-slow, 300, 150, 100, 75, 60, and 50.

Why is this important? Simple. A "normal" heart rate for an adult is 60 to 100. In other words, there should be between 3 and 5 large blocks between R waves. If there are less than 3, it's a tachycardia. If there are more than 5, it's a bradycardia.

Many tachyarrhythmias (or tachydysrhythmias for you purists out there) present at rate of about 15o. Atrial flutter with 2:1 conduction, for example (since flutter waves often occur at a rate of 300 or 1 large block). I would actually like to flog the person who started the rumor than if a heart rate exceeds 150, then it can't be sinus tachycardia.

If a heart rhythm is so fast that it only shows 1 large block between R waves, then you know the rate is about 300, and you need to suspect an accessory pathway. Sometimes this turns out to be atrial flutter with 1:1 conduction. If the rhythm is atrial fibrillation, and the shortest R-R interval is 1 large block or less (actually 6 small blocks or less) then leave the drugs for rate control in the drug box! You're probably looking at atrial fibrillation with WPW, and almost all drugs for rate control are contraindicated.

Anytime you're holding a rhythm strip in your hand, take a good look at the R-R intervals, and get a feel for how many large blocks are between the R waves. Before long, you'll be able to estimate the heart rate at a glance!

ACC/AHA 2008 Statement on Performance Measurement and Reperfusion Therapy

The ACC/AHA 2008 Statement on Performance Measurement and Reperfusion Therapy was published on 11/10/08.

Here are some highlights (from the prehospital perspective) with comments:

"Acute reperfusion therapy, either with fibrinolytic therapy or percutaneous coronary intervention (PCI), is one of the most important treatments for patients with ST-segment elevation myocardial infarction (STEMI)...The timeliness of reperfusion therapy is of central importance, because the benefits of therapy diminish rapidly with delays in treatment."

How rapidly? Consider this graph from Early thrombolytic treatment in acute myocardial infarction: reappraisal of the golden hour. Lancet 1996;348:771-775.


As you can see, with fibrinolytic therapy, the highest benefit is in the first hour. After 3 hours, the benefit drops off rapidly.

How important is prompt, expertly performed PCI? Consider this graph from Time to Treatment in Primary Percutaneous Coronary Intervention, N Engl J Med 2007;357:1631-1638.

As you can see, there is a significant increase in mortality for every 15 minutes of delay past 90 minutes.

"Thus, ACC/AHA guidelines recommend that fibrinolysis be provided within 30 minutes of first medical system contact and that primary PCI be provided within 90 minutes of first medical system contact for patients presenting with STEMI..."

That only makes sense. The ideal situation would be to measure from the time of symptom onset, but considering the average patient delay and the difficulty in pinpointing the exact moment of symptom onset, "time from discovery" is the most logical option.

"Beginning in 2004, the ACC/AHA STEMI guideline recommendations for both fibrinolysis and primary PCI recommend that patients receive therapy within a limited time from first medical system contact rather than from the time of presentation at an acute care facility."

It's almost 2009, so we're coming up on 5 years since the 2004 guidelines came out. We should have made some serious progress toward measuring EMS-to-balloon (E2B) times, right?

Wrong.

"However, the current time-to-reperfusion measures reported by CMS and the Joint Commission and those endorsed by the ACC/AHA use the time of hospital presentation as the 'start time.'"

I'm confused. Why the discrepancy?

"The time of hospital presentation at a healthcare institution has been used as the index time for several reasons. Practically, systematic approaches to collecting data on the time of first system contact have not been assessed or validated, whereas the time of presentation at an institution is routinely available in records."

What could be simpler than looking at the EMS run sheet? I'm trying to be polite here, but what would the authors consider "validation" that EMS times are accurate?

"Furthermore, the appropriate definition of first medical system contact (eg, emergency medical services system activation versus time of first in-field ECG) is a topic of substantial debate."

Interesting that no footnotes appear after this comment. Questions? Sure. But substantial debate? If you're that worried about it, capture both time stamps.

"The use of time of presentation, the standard that has been used in previous measures, also provides consistency across time."

All you have to do is capture the arrival time at the hospital. Then you're free to continue your apples-to-apples comparisons. In fact, you could even measure the in-hospital impact of the out-of-hospital 12 lead ECG.

"Finally, issues of accountability with the time of first system contact are substantially more complicated than those surrounding the current reperfusion measures. Specifically, because current public reporting efforts focus on institutions rather than systems, measures that include the time from first system contact could potentially penalize institutions for issues beyond their control."

If the current public reporting efforts focus on institutions and not systems, then how could they be punished? According to Dr. Alice Jacobs, non-PCI hospitals are already being punished by Medicare when they lose STEMI patients to hospitals capable of primary PCI.

Show me the hospitals that have tried to work with their local EMS systems and were frustrated by a complete lack of cooperation. I'm thinking they're few and far between. From what I've seen, EMS wants to be engaged.

"The work group acknowledges, however, that the goal of evolution toward measuring the time of first system contact to reperfusion is appropriate for several reasons."

The evolution toward measuring the time of first system contact, which the guidelines recommended in 2004? How many more years need to go by?

"First, with evolving health information technology, determining the time of first system contact is likely to become easier and more consistent."

Because EMS hasn't been documenting our call received time, arrival time, and so on, until recently?

"Second, the measures should remain consistent with guidelines whenever possible, presuming that practical barriers can be overcome."

Does this really need to be verbalized?

"Finally, as systems of care to provide reperfusion proliferate, an understanding of the performance of these systems becomes increasingly important."

Then get with the times! (No pun intended).

"Measuring the performance of systems is likely to foster the collaboration among multiple systems, including emergency medical services, that is necessary to ensure optimal quality of care."

Exactly. So...?

"Although the work group agrees that performance measurement should migrate toward an approach of using the time of first system contact, it currently advocates the development of such measurement for quality-improvement purposes rather than for public reporting, with an explicit goal of addressing the issues described above as part of the implementation process. Such implementation testing would lay the foundation for the use of measures of time from first system contact to reperfusion as measures for the purposes of public accountability."

EMS-to-balloon (E2B) is an idea whose time has come. Hopefully the success of those STEMI systems that are already following the guidelines will prove once and for all that it can be done.

Honoring Our Veterans

To all the brave veterans of America's wars, the Prehospital 12 Lead ECG blog says "Thank you for your service to our country!"


Today Engine 6, Medic 6, and Truck 6 had the honor of attending the Veteran's Day Memorial service at Shelter Cove Community Park.

The keynote speaker was Medal of Honor recipient Major General James E. Livingston - Retired. To my knowledge, this is the first time I've seen a Medal of Honor recipient in real life. Like all Medal of Honor recipients, the citation for his medal is amazing (see link).

The Parris Island Marine Band was also in attendence, and did a fantastic job (as always). Oorah!

Remembering the sacrifice of America's heroes gave me pause to consider the sacrifices that I haven't made in the service of my country.

I remember the quote from the 2002 adaptation of The Four Feathers. "Dr. Johnson once said, 'Every man feels meanly about himself for not having been a soldier.' Well, that's something no one here tonight need fear."

I do feel meanly about myself for not having been a soldier. I often wish I would have joined the military right out of high school. I serve my community as a firefighter and a paramedic, and while the job can be dangerous, no one's shooting at me (at least not yet).

In WWII, every man, woman, and child sacrificed. My father once told me a story that illustrates this point. The year was 1942 or 1943 and my father was in the 1st or 2nd grade at St. Gabriel Elementary School in Detroit, Michigan (near Dearborn). The school was run by the Dominican nuns of Adrian. During WWII, scrap metal drives were common, so in the front yard of the rectory, there was a pile of scrap metal. One day when the pile was big enough, a truck came by to pick it up. Before it was taken away, the nun who was the principal of the school (my dad thinks her name was Sister Alphonse) threw the school bell on top of the pile.

Are you listening, Steven Spielberg?

My father went on to mention ration cards. When I asked what they were, he explained they "allowed you to buy things that were hard to get." You know. Things like butter.

The most I've sacrificed in the war on terror is longer lines at the airport and perhaps higher fuel prices.

There's something wrong with that.

My dad went on to serve his country in the U.S. Army. Fortunately for him (and perhaps for me), the Korean War ended while he was in boot camp. He was stationed in Fort Richardson, Alaska.

My heartfelt gratitude goes to all who served, and all who still serve; especially those who were killed, those who were wounded, and those who were left behind.

Thank you for my freedom.

ECG Challenges from AACN Advanced Critical Care

In my recent post the problem of ST segment elevation we discussed the difficulty of distinguishing between acute STEMI and the various mimics of acute myocardial infarction.

Here are some articles from the American Association of Critical Care Nurses that are worth reading.

ECG Challenges - Myocardial Infarction Mimics Q Waves
AACN Advanced Critical Care, Volume 18, Number 4, pp. 440-444

ECG Challenges - ECG Diagnosis of Acute Coronary Syndrome
AACN Advanced Critical Care Volume 19, Number 1, pp. 101-108

ECG Challenges - Myocardial Infarction Mimics ST Segments
AACN Advanced Critical Care, Volume 19, Number 2, 245-248

If you have access to the medical journals, these are also worth checking out:

Electrocardiographic ST-segment elevation: correct identification of acute myocardial infarction (AMI) and non-AMI syndromes by emergency physicians. Acad Emerg Med. 2001 Apr;8(4):349-60. PMID: 11282670

ST-Segment Elevation in Conditions Other Than Acute Myocardial Infarction. N Engl J Med. 2003 Nov 27;349(22):2128-35. PMID: 14645641

You can test your ability to identify the STEMI mimics by taking the ACC-D2B ECG Challenge here.

63 yom CC: chest pain

Here's an interesting case submitted by my friend Lt./NREMT-P Chris B. This is all the information I have, so I won't be able to answer any questions about the history, clinical presentation, or physical exam.

You are dispatched to a 63 year old male complaining of chest pain.

On arrival you find the patient lying supine in bed, alert and oriented to person, place, time and event. His general appearance is poor. He is pale, but not diaphoretic. Skin temp is normal. His chest pain is substernal 6/10 and non-radiating.

Vital signs:
Resp: 12 non-labored
Pulse: 68
BP: 97/55
SpO2: 81 RA
Breath sounds: clear

Past medical history:
CABGx4 approx 6 years ago
End stage renal disease
Diabetes

The cardiac monitor is attached and shows this heart rhythm:

A 12 lead ECG is performed:

How sick is this patient?

What do you think is going on?

What is your treatment plan?

Precordial Leads - The Transition, R-Wave Progression, R/S Ratio in Lead V1

Since we covered the first 6 leads of the 12 lead ECG in the 6-part tutorial on axis determination, a few words about the precordial leads might be in order. These are leads V1-V6, the unipolar leads that are placed directly on the patient's chest.

The heart is a 3 dimensional object, and calculating the heart's electrical axis in the frontal plane tells us nothing about whether or not the heart's electrical axis is anterior or posterior, for example. This 3rd dimension that can be calculated using the precordial leads is sometimes referred to as the Z-axis (think of the Cartesian coordinate system).

I'm never one to say "you don't need to know that". The words will never come out of my mouth, at least not in an educational setting. However, I will say that I have not found an exact calculation of the Z-axis to be clinically useful. Maybe it is useful to cardiologists. I really don't know, and it's possible that my opinion will change in this matter.

The following image comes from The Textbook of Medical Physiology 9e; © 1996 Guyton AC, Hall JE; WB Saunders.

Here's what I teach my students.

The QRS complex should start out negative in lead V1. The QRS complex should end up positive in lead V6. Somewhere in between, there should be an equiphasic QRS complex and this is referred to as the transition. This most often occurs in lead V3 but is highly dependent on lead placement. When the transition happens in lead V1 or V2 it is referred to as an early transition. When it happens in leads V4, V5, or V6 it is referred to as a late transition.

In addition, there should be a gradual increase in the amplitude of the R-wave between leads V1-V4. This is referred to as R-wave progression. Lead V1 may or may not have an R wave, but one should show up by lead V2 and get a little taller in lead V3 and reach its maximum height in lead V4 or V5. Again, this is highly dependent on lead placement.

With an early transition, the R wave is sometimes taller than the S wave in lead V1. This is referred to as an R/S ratio > 1, and it could indicate a serious problem. Even when this finding is in lead V2 you should take a second glance. We'll cover this in more detail on another day, but for now, here is the differential diagnosis of tall R waves in lead V1. This is taken from Mattu, Brady, et al. Prominent R Wave in Lead V1: Electrocardiographic Differential Diagnosis; Am J Emerg Med 2001;19:504-513:

• Right bundle branch block
• Left ventricular ectopy
• Right ventricular hypertrophy
• Acute right ventricular dilation
• Wolff-Parkinson-White syndrome Type A
• Posterior myocardial infarction
• Hypertrophic cardiomyopathy
• Progressive muscular dystrophy
• Dextrocardia
• Misplaced precordial leads
• Normal variant

As a side note, for the past 2 consecutive weekends I helped teach ACLS to a group of PA students in Savannah, GA. I taught Asystole, PEA, bradycardia, and ACS. I absolutely despise the new DVD driven format of ACLS. I'm sure the AHA had their reasons, but the class should be re-named "Introduction to ACLS" or "ACLS Awareness" because the DVDs simplify things to a fault. Anyway, I couldn't help but notice during the ACS video that the "paramedics" placed leads V1 and V2 one intercostal space too high! That's ironic, because that is by far the most common mistake clinicians make when placing the electrodes for the precordial leads. When they are placed in this manner, the result is often abnormal R-wave progression on the 12 lead ECG.

Poor R-wave progression (or "poor anterior R-wave progression") is a non-specific finding on the 12 lead ECG. However, it could be an indicator of a more serious problem.

Why is this an issue? Simple. Do we transport every patient to the hospital? No. Do we usually have an old ECG for comparison? No. Do most 80 year old patients have a normal ECG? No. I hear all the time how paramedics don't need to know how to interpret a 12 lead ECG to a high level. Of course we do! How else can we correctly advise Mrs. Smith of the risk she's taking when she refuses care?

In addition, it's impossible to interpret ST segment depression, ST segment elevation, and T wave abnormalities if you don't understand the various conditions that cause them.

Take for example the ECG used in Part IV of the axis determination tutorial. This ECG was captured on an emergency call of a 16 year old girl with a congenital heart defect. The call was for "acute shortness of breath" and the family advised dispatch that she was in "heart failure". Look at the T waves in the right precordial leads. They're inverted! And the ST segments are depressed! That's acute coronary ischemia, right? Wrong. It's a strain pattern from right ventricular hypertrophy. Note the tall R waves in lead V1. It turns out the girl was having a panic attack. Do you see why paramedics need to understand 12 lead ECGs?

Here are some parting words from Chou's Electrocardiography in Clinical Practice, Fifth Edition, © 2001 Saunders, ISBN: 0-7216-8696-4:

"The widely used term "poor R wave progression" is not helpful. In many cases the abnormally low R amplitude extending from the right into the mid or left precordial leads indicates myocardial infarction of the anterior wall. Such a pattern occurs also in the presence of left ventricular hypertrophy and in normal subjects without cardiac or pulmonary disease. It may be caused by a shift of the transitional zone to the left or by an atypical (abnormally high) placement of the mid-precordial chest electrodes. For this reason it is advisable to report the most likely cause of "poor R wave progression" in each case."

Fishin' with Fuzzy

I apologize for my absence, but I have a good excuse! Yesterday, my crew and I took advantage of a rare opportunity to fish with the legendary Captain Fuzzy Davis!

The result? Lots of fish.

D2B times at Parma Community General Hospital

Last week I was browsing around the D2B Alliance website and clicked on a section called Hospital D2B Stories. The very first listing was Parma Community General Hospital, Parma, OH - learn how PCGH achieved 85% of patients treated within the 90 minute goal. This caught my eye. It just so happens that I graduated from PCGH's paramedic program in 1995.

Here are some highlights:

"[T]he hospital was struggling to achieve door-to-balloon times under 90 minutes (2004 average was 119 minutes). After identifying physician champions, the multidisciplinary Code STEMI team was identified and includes the ED physician and staff, on-call interventionalist, cath lab staff (including on-call), registered nurse and the surgical intensivist from the heart center, respiratory therapist, a lab phlebotomist and supervisor of the quality department.

"The hospital team at Parma Community committed to and implemented all of the D2B strategies (i.e., ED physician activation of the cath lab, one call activation, cath lab team ready in 20-30 minutes, prompt data feedback, senior management commitment and team-based approach) beginning January 1, 2006. Some additional procedures and strategies the hospital developed include designation of an on-call interventionalist and commitment from the clinical departments to provide staff on an immediate basis 24 hours per day. The hard work of the hospital team paid off as average D2B times decreased from 119 minutes in 2004 to 68.9 minutes in 2006 with 85% of patients treated within the 90 minute time goal."

It goes on to explain some of the barriers they had to overcome to achieve these impressive results.

I have a confession to make. My first reaction to this success story was that the emergency medical services were conspicuously absent from the multidisciplinary Code STEMI team. In addition, it said that PCGH implemented all of the D2B strategies, but it didn't list the optional strategy of activating the cardiac cath lab based on the prehospital 12 lead ECG.

A few days later, I chanced upon an article at Cath Lab Digest entitled Parma Hospital's "Code STEMI" success story.

This article did mention EMS.

"The Code STEMI process continues to evolve and produce outstanding door-to-balloon times through effective partnerships and communication. The “Touch-and-Go STEMI” is a phrase that has been used to describe the process by which a patient is brought directly to the ED by the EMS squad for confirmation of the 12-lead ECG results by the ED physician, then is immediately transported to the cath lab (while still on the EMS stretcher). This method has allowed our center to achieve 15- and 16-minute door-to-balloon times.

"In a Touch-and-Go STEMI, the cath lab inherits many of the ED’s responsibilities such as blood draws and administration of medications. The Heart Center RN gathers data, including the patient’s name, height, weight and allergies. The hand-off is completed with direct communication between the ED physician and the cardiologist and the ED and cath lab nursing staff..."

"The Code STEMI process and performance measures are reviewed at committee meetings, and revisions to the process are implemented. Door-to-balloon time feedback is provided to the fire chiefs to share with the EMS squads to demonstrate how their actions in the field directly save heart muscle and improve patient outcomes..."

"Physician and nursing leaders have presented this striking data to local EMS departments to provide continuing education on the current guidelines and to reinforce that our center is the best in the area for treatment of STEMI patients..."

"Partnership with local EMS providers who have 12-lead ECG transmission equipment, utilization of a coordinated one-step notification process, and establishment of well-defined roles and performance measures with feedback have significantly improved door-to-balloon times at Parma Community General Hospital."

I still had some questions, so I followed up with an email to PCGH. I was very impressed with the response I received! It turns out the communications specialist who received my email has a husband who is also a graduate of PCGH's paramedic program. Now he's an RN who works with STEMI patients in the Heart Center!

I also received an email from the data coordinator for cardiac services. Here's what she had to say.

"The ER receives a 12 lead EKG via cell phone transmission. The LikePak 20 [sic] is connected to the patient then to a cell phone and transmitted to our ER. The ER physician calls the Code STEMI (CS) team based on the 12 lead ekg (emphasis added). No cardiologist interpretation is necessary. The CS team assembles prior to the arrival of the patient to the ER. Upon arrival, the 12 lead ekg is confirmed by the ER physician, the patient is registered and taken immediately to the Cath Lab. On many occasions the patient has been met at the ER door by the cardiologist and the CS team which accounts for our 16 minute door to balloon times. Our process is the same day or night, weekdays or weekends or holidays. All area EMS systems are able to transmit 12 lead EKGs (emphasis added).

A Code STEMI poster is distributed to the depts usually within 24 hours of the event. The door to balloon time is noted and all of the staff in the ER, ED and our Heart Center are recognized. On a monthly basis, the fire chiefs of each surrounding community are emailed a report with the door to balloon times which includes all of the communities times. Our EMS coordinator is in regular contact with the communities and serves as a resource."

That's awesome! Congratulations to the Code STEMI team at Parma Community General Hospital!

I knew I came from good stock! :)

P.S. I emailed the Cath Lab Manger to ask about their rate of false positive activations, but so far I have not received a reply.

*** UPDATE 12/19/08 ***

To download a podcast with Parma Mayor Dean DePiero and Fire Chief John French, right click this link and select "save as". Note: I had to download the file, right click it, and change the file extension to .mp4 in order to listen to the podcast with MS Media Player.

The honor formerly known as the Superior Scribbler Award

Rogue Medic has bestowed upon Prehospital 12 Lead ECG the Superlative Hieroglyphicist Award (also known as the Superior Scribbler Award).

Here's what Rogue Medic had to say:

"Prehospital 12 Lead ECG by Tom B. is a great blog about cardiology from a prehospital perspective. He understands 12 leads, how to teach them, and he is always trying to learn more. Many medics will take the approach that nobody needs to learn that much about cardiology. These are not people you want to have caring for you or for anyone you care about. If you want to understand 12 leads, Tom B. can help you."

Rogue Medic was the first person to link to my blog, and I appreciate it. Thank you, Rogue Medic!

The rules state that "every Superior Scribbler will name 5 other Super Scribblers. If you are named you must link to the author & the name of the blog that gave you the award. Then you must display the adorable award and link to THIS POST, which explains the award. The same post also allows you to add your link. Then they will have a record of all the people who are Super Scribblers!"

I'm embarassed to admit it, but I'm not sure I can name 5 additional blogs! I just started blogging and Rogue Medic and JB on the Rocks have already been named as recipients; but I'm re-naming them because the "rules" appear to be flexible (for example, the arbitrary re-naming of the award by Ambulance Driver).

As I noted in my introduction, Capnography for Paramedics was my inspiration to start blogging. That blog has been inactive for the last 2 years, but apparently the author still blogs at Street Watch: Notes of a Paramedic.

I recently learned (through statcounter) that EMS Haiku links to me. That's good, since I admire Japanese culture (at least the version I read about in Shogun) and I enjoyed writing haiku poems in high school. So I can't help but be impressed with a poem like this:

Cruising the dark streets
Radio, MDT beep
Light them up again

The only other blog I follow on a regular basis is Thick As Thieves. Bobbe Edmonds is an incredibly skilled martial artist and instructor of Pencak Silat and Kali. I found him on YouTube and his video clips have added much to my understanding. His blog has nothing to do with medicine. In fact, I'm not sure how I'd classify it. Regardless, I generally find his perspective interesting, perhaps because it's different!

That makes five! Let it not be said that I don't obey the rules!

Sort of.

October 18, 2008: Dr. Jacobs and Dr. Gibson Discuss Mission: Lifeline - The AHA STEMI Initiative

Click here to see Dr. Alice Jacobs and Dr. C. Michael Gibson discuss Mission: Lifeline.

One part that I found interesting:

05:19 Dr. Jacobs: "In addition to the fact that only 50% of patients dial 9-1-1 and activate EMS, we know 10 to 15% of [EMS] vehicles have prehospital [12 lead] ECGs...although it's said 70 to 80% of the population live within an hour of a PCI facility, 43 million people in the rural areas do not. We know that there are disincentives...cardiac patients are profitable, and something I learned by doing all of this is that Medicare reimburses a hospital based on an acuity index, and cardiac patients have a high acuity index, and if you lose them, your acuity index drops, so you're reimbursed less for everything else...so all of those are disincentives or difficulties in establishing these regional networks...one of the unique things about Mission: Lifeline is we preserve a role for the non-PCI community hospital -- they're called STEMI referral hospitals -- and our hope is that working with the payers and the policy makers, that they [receive an incentive] to treat by the guidelines and rapidly transfer patients to a PCI facility..."

So, non-PCI hospitals are punished by Medicare when they transfer patients for primary PCI. It's no excuse for letting politics trump patient care, but it's wrong, and it needs to change.