 Welcome back to our MedSmarter question of the week, where we're taking a smarter approach to preparing future physicians. Before we get started, if you'll take just a quick minute and click that like button and also subscribe and turn the bell on so that you'll be notified when we post new videos. Let's get right into that question. As always, we start with the last sentence of the vignette and then read the rest. Based on these findings, the physician concludes that the symptoms are due to pathology of which of the following fetal structures. A 37-year-old man with no significant past medical history presents to his primary care physician complaining of shortness of breath on exertion for the past several months. The patient also acknowledges recent heart palpitations but denies cough, chest pain, lower extremity edema, nocturnal dyspnea, and weakness. He further denies any recent illness and he states that he does not smoke. Cardiac examination shows an irregularly irregular rhythm, a widely split and fixed S2, as well as a mid systolic ejection murmur over the left upper sternal border. ECG reveals that the patient is an atrial fibrillation. Based on these findings, the physician concludes that these symptoms are due to pathology of which of the following fetal structures. The first thing we want to do is figure out what is the most important thing to take away from this question before we look at our answer choices. So we have a 37-year-old man and he's having shortness of breath on exertion. Of note, he has had some heart palpitations and it does tell us later that these heart palpitations are irregularly irregular rhythm. It also has a split and fixed S2 as well as a mid systolic ejection murmur. All of those things should lead us in a very specific direction to come up with our answer choices. He is in atrial fibrillation, which is exactly what this irregularly irregular rhythm tells us. So take a minute, look at these answer choices, look back over the question, come up with an answer, and put your answer in the comment box below. Alright, so let's go through these together. Let's start with A, ductus arteriosus. The ductus arteriosus is what connects our systemic circuit backwards into the pulmonary circuit. During fetal life, that actually pushes blood away from the pulmonary circuit into the systemic circuit. And then once a baby is born, then that reverses due to the higher pressures in the systemic circuit. This however doesn't cause a mid systolic ejection murmur, it causes more of a machine like murmur. So that's going to be an option I would not choose. Option B, aorticopulmonary septum. This is going to be what separates the aorta and the pulmonary trunk. That won't cause any of these things that we're seeing here in this vignette, so that's not an option for me as well. The ductus venosis, that's actually a vessel that's between the portal circuit and the inferior vena cava, so it's not even in the heart area, so therefore that's not something I'm going to even consider. The intraventricular septum, this is going to be what we see where we have ventricular septal defects caused by problems in the intraventricular septum formation during fetal life. That usually can give us some exertional dyspnea that would match this patient's presentation. However, this doesn't usually go silent up through most of their life, like we see here with this patient that just started at 37 years of age. This is going to be a pan systolic murmur and doesn't match the mid systolic ejection murmur that is heard on this patient. Therefore D is not an answer choice. That leaves me with E foramen ovale. This is something that matches every single one of these potential symptoms and signs and is going to be my answer choice after we've already eliminated all the rest of them and it does match with what I would want to choose. So E would be my final answer. And E is the correct answer. So we are looking at a patent foramen ovale in this patient. Typically the foramen ovale closes completely shortly after the baby takes their first breath. We have that shifting of the pressures of the heart that will cause the flap with the foramen ovale to close and when it closes it slowly heals itself to a point where it is no longer open. There is a small amount of people that do have a patent foramen ovale that goes undetected up through into adulthood. In fact we had a famous musician Brett Michaels that was diagnosed with a patent foramen ovale because he had a stroke that left his lower body and ended up in his brain and the only way that something like that can happen is if we have a communication between the venous side and the arterial side of the body because the lungs would filter those clots out and you would have a pulmonary embolism rather than a stroke. So because he did have a venous occlusion that broke off, went into and caused a stroke we knew there had to be some sort of a connection there. So Brett Michaels at the age of 47 was diagnosed with a patent foramen ovale. So this patent foramen ovale can cause atrial fibrillation which is that irregularly irregular pulse that we saw discussed in this previous vignette and it can give us palpitations. That's kind of the sensation of atrial fibrillation and then like we mentioned with Brett Michaels that can cause stroke in patients that shouldn't have strokes coming from the venous side of the body. That's what's known as a paradoxical emboli. One other thing to note here, the aorticopulmonary septum this is a derivative of the truncus arteriosus from the fetal life and the truncus arteriosus is most commonly seen with the problem of the transposition of the great vessels. So what you would see with patients here is that the venous system coming into the right side of the heart gets pumped out through the aorta rather than going through the pulmonary circuit. So these patients will see early cyanosis and you're definitely going to have these symptoms show up immediately in emphysema upon birth. If you found this material helpful for your studying, please like and consider subscribing to the channel. Also, share this video so that more people can benefit from it like you have.