Incidental Finding of Systolic Murmur in an Asymptomatic Adult

A 35-year-old woman presents for a periodic physical exam with Pap and HPV testing. She states she's feeling well without complaint and has excellent exercise tolerance, running about 30 miles per week. Her current medications include an levonagestrel IUD for contraception. Physical exam includes vital signs within normal limits, a BMI of 23, and no unusual findings, save for a mid-systolic click followed by a grade two, mid to late systolic murmur with a honking quality. The murmur moves forward into systole with position change from supine to standing and does not radiate beyond the precordium. These findings most likely represent:

A. A physiologic murmur

B. The murmur of aortic stenosis

C. The murmur of mitral valve prolapse

D. The murmur related to tricuspid valve incompetency

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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 Dr. 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 35-year-old woman presents for a periodic physical exam with pap and HPV testing. She states she's feeling well without complaint and has excellent exercise tolerance, running about 30 miles per week. Her current medications include a levonorgestrel IUD for contraception. Physical exam includes vital signs within normal limits, a BMI of 23, and no unusual findings, save for a mid-systolic click, followed by a grade two mid to late systolic murmur with a honking quality. The murmur moves forward into systole with position change from supine to standing and does not radiate beyond the precordium.

These findings most likely represent:

A. A physiologic murmur
B. Murmur of aortic stenosis
C. The murmur of mitral valve prolapse
D. A murmur related to tricuspid valve incompetency

The correct answer is C, the murmur of mitral valve prolapse.
Where should you start? First, determine what kind of a question this is. Given we are provided with a clinical finding and asked what this represents, this is a diagnosis question, or at least a working diagnosis question.

A bit of background information. The condition mitral valve prolapse is most likely the most common valvular heart problem, and it's been estimated to be present in up to 10% of the population. And if you're saying to yourself, "Gee, one in 10 people, that seems like a lot," it's often missed, or else it's picked up for the first time in the course of a physical exam in a person who's well into their adult years and has probably had this all their lives. The murmur described in this case study is classic for the murmur of mitral valve prolapse. I've said it before, I'll say it again: the presentation of conditions on the boards will be right out of the textbook like this is.

To understand this murmur, consider the following: with mitral valve prolapse, one of the two mitral valve leaflets is longer than is typical. Therefore, when the valves approximate, the longer of the two leaflets prolapses into the left atrium, and this results in the characteristic mid-systolic click followed by a mid-to-late systolic murmur, and it is often described as having a honking quality. The murmur will move forward into systole with position change from supine to stand. It doesn't get louder; it just takes up more of systole.

If you're still having difficulty conceptualizing this, here's a visual that I find helpful and I've shared with many people over the years as I've taught classes on honing your cardiac exam. Let's say that you have a size 8 foot and somehow or another you're able to take your size 8 foot and squeeze it into a size 6 and a half shoe. You get both the toe and your heel of your foot into this shoe that is clearly way too small for you. What is the middle part of your foot going to do? It's going to buckle or prolapse. And that's what happens with the murmur of mitral valve prolapse.
The majority of people with mitral valve prolapse, which is far more common in females, do not have any symptomatology—no chest pain, no activity intolerance, or the like. And that's what we have in this case scenario. She is a long-distance runner, does this every week, no exercise intolerance, no chief complaint. In other words, this murmur was an incidental finding on an otherwise normal exam. And just to make sure you have a definition of an incidental finding, that's something that you encounter on physical exam that you just weren't expecting.

The degree of distress, such as chest pain and dyspnea, which is sometimes reported in people with mitral valve prolapse, is really quite dependent on the degree of mitral regurgitation. Although some studies have failed to reveal any differences in the rates of chest pain in patients with or without mitral valve prolapse. However, there is this smaller group of patients with mitral valve prolapse that has systolic displacement of one or more of the mitral valve leaflets into the LA with valve thickening and redundancy, usually accompanied by mild to moderate mitral regurgitation. This group typically has additional health problems such as Marfan syndrome or other connective tissue disease and often have issues with activity intolerance and non-ischemic chest pain. However, that's not what we have here. So the people who are symptomatic with mitral valve prolapse are often classified as having mitral valve prolapse disease, and they're a very small subsection of people who have the murmur of mitral valve prolapse. And what we have in this scenario is a woman who is well, no chief complaint, excellent activity tolerance.

With this background information, let's take another look at the question. A 35-year-old woman presents for a periodic physical exam with pap and HPV testing. She states she's feeling well without complaint and has excellent exercise tolerance, running about 30 miles a week. Her current medications include a levonorgestrel IUD for contraception. Physical exam includes vital signs within normal limits, a BMI of 23. No unusual findings save for a midsystolic click followed by a grade two mid to late systolic murmur with a honking quality. The murmur moves forward into systole with position change from supine to standing and does not radiate beyond the precordium.

So just before we get into the answers here, a couple of comments on what I just read off. "Does not radiate beyond the precordium" means the murmur doesn't radiate to the axilla. It doesn't radiate to the neck. In other words, it's within the precordium or the chest region.

All right. So back to looking at the responses here. These findings most likely represent:

A. A physiologic murmur. This is incorrect. Please recall, anytime you pop the term "physiologic" in front of anything, it implies that this finding is noted in the absence of pathology. A physiologic heart murmur is noted in a person with a structurally normal heart without signs or symptoms of cardiac issues, including shortness of breath, activity intolerance, or the like. The physiologic murmur is described as an early to midsystolic murmur that does not radiate beyond the precordium, usually grade two in intensity, and softens or just plain disappears with position change from supine to standing. Clearly, that's not what is being described here. And it might be tempting to go with the answer physiologic murmur because this woman really is quite well, but obviously this is not the correct response. Physiologic murmurs are often called flow murmurs, and the better term is in fact physiologic murmur. And often the patient will report that they "had a heart murmur as a child, but I outgrew it." The commonality this case study shares with the person who has a physiologic murmur is, one more time, great activity tolerance, unimpaired by the presence of the murmur, which makes sense because there's nothing structurally wrong with the heart in a person with a physiologic murmur. Truthfully, if we could put a group of healthy adults in soundproof rooms and have expert cardiac auscultators examining these folks, we would find a much higher percentage of people with physiologic murmurs than we do in the regular population. So why do we miss physiologic murmurs so often? Lots of times it's because they're a grade one murmur, and a grade one murmur is really hard to hear. One last point on physiologic murmurs: they're also very common in children and teens. And as I mentioned, often they can't be heard by the time the person is in their 20s and 30s. And part of this is simply related to the fact that the chest wall usually gets thicker as people get older, even when they're only in their 20s or 30s, and therefore you can't hear that murmur anymore.

Option B, the murmur of aortic stenosis. I've mentioned this numerous times in this podcast. Always think who is most at risk for a given condition before you answer an exam question. Who is most likely to have aortic stenosis? Well, this gets back to pathophysiology. And the pathophysiology of aortic stenosis is as such: the aortic valve becomes stenotic due to aging. And with that aging of the valve, that can be really accelerated by hypertension, particularly poorly controlled hypertension, dyslipidemia, and a number of other comorbidities. Therefore, the most common person with an age-related murmur of aortic stenosis is a person who is 70-plus years old with some kind of comorbidity like long-standing high blood pressure. Obviously, that doesn't describe this woman. In addition, the murmur of aortic stenosis is heard during systole, often with a crescendo-decrescendo pattern. In other words, it gets louder then it gets softer, starting in early systole, and there is radiation to the neck. In other words, you hear the murmur in the chest, but then you also hear it up in the carotids. With high-grade aortic stenosis, there is usually a complaint of activity intolerance and the notation of a narrow pulse pressure on blood pressure. It might be something like 105 over 90 and other components of low cardiac output. Is there such a thing as a congenital aortic stenosis where the aortic valve doesn't open to its natural orifice because of a valve issue present at birth? Yes, that's rather uncommon and typically is diagnosed in early childhood. I'll do a podcast on that at a later time because I've picked up the murmur of congenital aortic stenosis over the years a number of times, to be honest with you, that was missed by other examiners.

C. The murmur of mitral valve prolapse. This is, of course, the correct answer. With the murmur of mitral valve prolapse, it's often an incidental finding on an otherwise normal physical exam. And you might well say, "Well, she's in her 30s. How come no one has picked this up before?" This sometimes happens in clinical practice where you end up being the most astute, skilled cardiac auscultator that has ever listened to the person's heart. And one of the things that's really important to consider is when you pick up something that truthfully other providers should have picked up in the past, they should have. There is no sense in saying, "Well, I found it and everyone else missed it." Just share your finding with the patient and say, "This is what I'm concerned about," and kind of leave it at that. Play down the fact that other people have missed it because sooner or later, you're going to miss something on a physical exam. It's not attractive to throw other providers under the bus. And I'll do another podcast on follow-up in mitral valve prolapse.

Option D, the murmur related to tricuspid valve incompetency. One more time, you are probably tired of me saying this because I've only said it about a bazillion times, but common diseases occur commonly. Keep in mind where the tricuspid valve is. It's on the right side of the heart, and most abnormalities found on the cardiac exam will arise from the left side of the heart. Therefore, on the boards, a test of entry-level NP competency in primary care, they are unlikely to throw you a curveball such as a right-sided heart valve problem. Indeed, I have been a nurse practitioner for more than three and a half decades now, and I'm not even going to get into how many years I've been an RN. I have literally seen one, count it, one person with tricuspid valve incompetency leading to the murmur of tricuspid regurgitation. In addition, the murmur of tricuspid regurgitation is a high-pitched, holosystolic murmur, meaning it takes up all of systole and is the same intensity throughout systole. I would say this is a zebra answer. Don't go for the zebras. Look for the horses. By the way, that one patient of mine who has a problem with her tricuspid valve, it is as a result of a congenital cardiac defect. It was picked up in early childhood. And it's interesting, whenever she is in the office, she's very gracious about this and she'll always say to me, "Do you have any students around today that want to listen to my heart?" because she appreciates that her murmur is not all that common and the students benefit from listening to it, and she greatly enjoys that role. By the way, she's totally asymptomatic with her murmur of tricuspid regurgitation.

Key takeaway: look at the entire scenario prior to choosing the correct answer. This is key to NP board success. Here we had a woman who truly appears well but had an incidental finding of a heart murmur. Look for the more common, look for the conditions that are typically more benign, and this is going to help you with NP board and clinical practice success.

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