Exertional Syncope Evaluation

A 17 yo male presents for follow up on a “fainting” episode that occurred during football practice at the end of a running exercise. He states, “I do not know what happened. We finished a set of running sprints and next thing I knew, I was on the ground.” He denies injury from the event and history of prior episodes. His physical examination reveals a crescendo-decrescendo systolic murmur heart best at the apex, increasing in intensity with position change from supine to standing position.  

This most likely represents: 

A. Mitral regurgitation 

B. Physiologic murmur 

C. Hypertrophic cardiomyopathy

D. Aortic stenosis 

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Transcript

Voiceover: Welcome to NP certification Q&A presented by Fitzgerald Health Education Associates. This podcast is for NP students studying to pass their NP certification exam. Getting to the correct test answers means breaking down the exam questions themselves. Leading NP expert Doctor Margaret Fitzgerald shares her knowledge and experience to help you dissect the anatomy of a test question, so you can better understand how to arrive at the correct test answer. 

So, if you're ready, let's jump right in. 

Margaret Fitzgerald: A 17-year-old male presents for follow-up on a “fainting” episode that occurred during football practice. At the end of a running exercise, he states, “I don't know what happened. We finished a set of running sprints and the next thing I knew, I was on the ground." He denies injury from the event and history of prior episodes. 

His physical exam reveals a crescendo-decrescendo systolic murmur heard best at the apex, increasing with intensity from position change from supine to standing. This most likely represents: 

A: Mitral regurgitation.  

B: Physiologic murmur.  

C: Hypertrophic cardiomyopathy.  

D: Aortic stenosis. 

And the correct answer is C: Hypertrophic cardiomyopathy. Where should you start with a question like this? First, determine what kind of a question it is. 

And given that we're provided with an abnormality on this teen's health history, what would that be? That's the fainting after running. And also find an abnormality on the physical exam. This is a differential diagnosis question. I know some might argue well, we don't have enough information here to make a diagnosis. You know what? You're right on that one. 

But here we're dealing with developing that working differential diagnosis. I'll get to the confirmatory testing in a few minutes. A bit of background information: hypertrophic cardiomyopathy, usually abbreviated HCM, is a disease of the cardiac muscle, and this condition of the ventricular septum is thickened and asymmetric. And that leads to potential outflow tract blocking of the heart. HCM can result from a variety of causes and this varies across the lifespan. 

But here we're talking about a teen and invariably when you're talking about teens and younger adults the HCM is genetic in origin. Patients will often exhibit symptoms of cardiac outflow obstruction with activity because the hypertrophic ventricular walls approximate with the increased force of myocardial contractility associated with exercise. However, most of the time the symptoms are post exertional, i.e., once the exercise has stopped and this teen is describing post-exertional syncope. 

And whenever you hear something like this, you should go like ding, ding, ding, ding, ding. Not many things cause somebody to truly faint after exertion. Indeed HCM is identified as the cause of at least one-third of all sudden cardiac deaths among younger athletes almost always, either during or immediately post-exertion. And this is again due to the cardiac outflow tract obstruction and or lethal ventricular rhythms. 

At the same time, patients with HCM are often without symptoms, particularly when not participating in increased physical activity. By the way, you're probably thinking how can avoiding something potentially life-threatening like this on the physical exam and when you're doing the sports clearance. And you know what? I know that there are some providers that say, oh, a sports clearance physical exam is uncomplicated. 

It's quick. You can get the kid in and out of the exam room in no time. You really do need to be aware that there can be some pitfalls to that abbreviated sports physical exam. How to avoid missing something. Dynamic auscultation, which means performing the cardiac exam while the patient either performs certain actions like the vowel sounds in maneuver, or is in different positions, such as supine to stand, squat to stand. 

There are a number of different maneuvers to summarize the impact of select components of dynamic auscultation with supine to stand and vowel sounds in the user. There's a decrease in cardiac preload, which means less blood is coming into the heart with squat position. There's an increase in preload, and I'll elaborate on these a little bit more with discussing the correct answers. 

With this in mind, let's take another look at the question. And I appreciate in real life, in the exam room with this young adult, we would dig more deeply into his HPI more into getting details on the single episode he's reporting, prior history of symptoms with exertion and at rest and a number of other issues. But as you probably have noticed from these podcasts, the boards give you just enough to answer the question and not much more. 

And that's what we have here. Again, let's take a look at the question. A 17-year-old male presents for follow-up on a "fainting” episode that occurred during football practice at the end of a running exercise. He states, “I don't know what happened. We finished a set of running sprints and the next thing I knew, I was on the ground.” 

He denies injury from the event and history of prior episodes. This physical exam reveals a crescendo-decrescendo systolic murmur best heard at the apex, increasing in intensity with position change from supine to stand. This most likely represent: A: Mitral regurgitation. This is incorrect. First of all, the murmur of mitral regurg is holosystolic, meaning it takes up all of systole-the same intensity throughout systole. 

Changing position from supine to stand usually has little, if any, influence on the intensity of the murmur. The other part is I've mentioned in many podcasts, is what would an athletic teen's reason be for developing the murmur of mitral regurgitation? Far more often found in older adults with advanced structural cardiac conditions such as left ventricular hypertrophy, heart failure, decades of poorly controlled hypertension. 

The list goes on and on. And in addition, with mitral regurg, there are seldom episodes of syncope reported, such as we have here. And the syncope should make you think if it's cardiac in origin, it's transient cardiac outflow tract obstruction. We'd get that in hypertrophic cardiomyopathy, but not in mitral regurgitation. B: Physiologic murmur. Also not the correct answer. 

Physiologic murmurs are noticed in the absence of cardiac structural abnormality. These are sometimes called innocent murmurs, functional murmurs. Or you might hear from a patient, "I had a heart murmur when I was a kid, but I outgrew it.” This term, the term that's most likely to pop up on boards and in practice is the term physiologic murmurs. 

How common are physiologic murmurs? Well, there have been studies that documented, if we had a group of healthy adults placed in soundproof booths with highly skilled clinicians, and we probably would find a grade I systolic murmur that's physiologic in nature in the majority of these folks. So why don't we hear physiologic murmurs more often is because, first, a grade I murmur is really hard to hear. 

Another is exam rooms are noisy. I know there's one exam room that I often use that has the ventilating system. Sounds like a jet airplane kind of taking off. In fact, sometimes both exam rooms. So I'm trying to do a really detailed cardiac exam because the blow of the ceiling in that room is so loud. I remember another time I was trying to pick up-and I did pick up-mitral valve prolapse murmur on a younger woman who was very healthy and all, and her 3-year-old was taking great exception to me, checking his mom's heart.  

Great exception. And he started telling me that I shouldn't be examining his mom and that kind of thing. So sometimes it's just noisy in exam rooms. 

So, the other thing is sometimes people's chest walls are just too thick. Obesity, tremendous physical conditioning that leads to thickened pectoral muscles. The list goes on and on. One of the key features of a physiologic murmur is as follows. When you go from supine to standing position, either the murmur softens or it disappears. So always remember that was dynamic auscultation with a physiologic murmur. Supine to stand the murmur softens or goes away. 

It is also early to mid systolic murmur. And you would also, with a physiologic murmur, not get an episode of syncope reported. You might also say to yourself yes, but remember. “Yes, but” are the two most dangerous words to introduce to your vocabulary during the NP boards, because it might mislead you. But let's get back to this. 

Yes, but this was a teen at football practice. He said he's been running. He was doing running sprints. He could be dehydrated, not having enough fluid that days. Perfectly logical thinking. But remember what would dehydrate have led to pre-syncope or a lightheadedness, not a fainting episode where he describes suddenly being on the ground and not remembering what happened. 

Remember, with true syncope, people go down. They often will have a minor injury from going down because they did nothing to stop their going down and becoming unconscious, and they will report I woke up on the ground or I woke up on the floor. I didn't know what happened. That's classic with syncope. So just to recap, dehydration, dizziness with exertion, pre-syncope, whole other condition. 

And you need to think of something pathologic like C: Hypertrophic cardiomyopathy. This is of course the correct answer. One key point of this very brief health history that we're given on this young adult is that he has a heart murmur that gets louder with going from supine to standing. The murmur associated with HCM is one of the very few murmurs that has this characteristic. 

The other part, and this is critical to making the correct assessment. Here is the post-exertional syncope because as I mentioned earlier, it's too often no good with HCM. Next step would be to order an echo. And if by chance this young adult came in to get his sports physical exam form signed so he can continue the football practice, he should not be participating in physically exerting activities until he's had cardiac clearance. 

And I know that breaks my heart. I've had to do that with some kids over the years, and it's painful because they just want to get back on the playing field, but it's too dangerous until this kid has received the cardiac workup. So the other part of it is, be aware in your community what resources you would have for getting a kid like this in to getting an appropriate cardiac workup. I know I'm very fortunate that the clinic where I practice, we have pediatric cardiology come up from Boston.  

It's about 30 miles and they come up and do a cardiac clinic a couple of times a month, particularly for kids. And all I have to do with a kid like this, and I realize this is incredibly fortunate situation is, lift up the phone, talk to the coordinator of that clinic, shoot over a clinical note and say, we need to get this kid cleared ASAP and they'll get them in the next time they're in town. 

So learn what your local resources are. D: Aortic stenosis. One more time. Think of who's most at risk for developing aortic stenosis. And aortic stenosis of course, is when the aortic valve does not open adequately. The vast majority of, as we'll see in clinical practice, is older adults, particularly as a result of advancing age and calcification, that of the aortic valve that again keeps it from opening to its full potential for long standing hypertension. 

Long standing dyslipidemia, particularly if poorly controlled, contributes to the development of aortic stenosis, which is characterized by a systolic murmur that radiates to the neck. The murmur remains unchanged or becomes a bit softer when going from supine to standing position. And just to recap: supine more blood in the heart; standing, less blood coming out of the heart. And that's why you'll see a lot of murmurs get softer when going from supine to standing. 

I grant you, about 1% of the general population will actually have congenital aortic stenosis. When one of the valve leaflets they remember this is a three cast valve doesn't open properly. And that could be in a 17-year-old coming for a sports physical who had a systolic murmur that radiates to the neck. But generally these folks are without worrisome symptoms like post-exertional syncope. 

Plus the murmur sounds quite different than the murmur of hypertrophic cardiomyopathy. Key takeaway: taking a history of activity tolerance or intolerance, including asking about any episodes of post-exertional syncope or chest pain coupled with dynamic auscultation, will really help the clinician find the patient who has hypertrophic cardiomyopathy. This truly can be potentially life saving. 

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