A 52-year-old man comes to the office due to a 2-week history of progressive fatigue and exertional dyspnea. The patient is a postal delivery worker and reports that he gets short of breath after walking a few blocks. He has not had chest pain or palpitations. The patient does not use tobacco, alcohol, or illicit drugs. Cardiac auscultation reveals a murmur that is best heard when the patient sits up and leans forward. He brings to the office the report from a recent cardiac catheterization (graph shown below). This patient's murmur would most likely be loudest at which of the following time points on the graph?

Question

A 52-year-old man comes to the office due to a 2-week history of progressive fatigue and exertional dyspnea.  The patient is a postal delivery worker and reports that he gets short of breath after walking a few blocks.  He has not had chest pain or palpitations.  The patient does not use tobacco, alcohol, or illicit drugs.  Cardiac auscultation reveals a murmur that is best heard when the patient sits up and leans forward.  He brings to the office the report from a recent cardiac catheterization (graph shown below).  This patient's murmur would most likely be loudest at which of the following time points on the graph?

Quizplus · Accepted Answer

11ec160b_3a78_8188_9249_6f9e6413e080_MD0001_00 This patient's cardiac catheterization shows a hemodynamic profile consistent with aortic regurgitation (AR); the characteristic decrescendo diastolic murmur is best heard with the patient leaning forward. The peak intensity of the murmur occurs just after aortic valve closure when the pressure gradient between the aorta and the left ventricle is maximal (point C). This pressure gradient falls progressively during diastole as blood regurgitates into the left ventricle, accounting for the decrescendo nature of the murmur. Notable changes to the pressure tracings that occur in AR include: (Choice A) This point corresponds to the start of left ventricular contraction, just after mitral valve closure and just prior to the opening of the aortic valve; it would mark the onset of the holosystolic murmur of mitral regurgitation. (Choice B) This is the peak systolic pressure produced by the left ventricle during systole; the peak intensity of the crescendo-decrescendo murmur of aortic stenosis is heard here. (Choice D) This point corresponds to mid-diastole. The murmur of AR is likely heard here as well, but at a lower intensity given the relatively lower pressure gradient between the aorta and left ventricle. The low-pitch rumble of mitral stenosis would also be heard at this time. (Choice E) This point marks the onset of left atrial contraction (atrial kick) just before closure of the mitral valve. Accentuation of a mitral stenosis murmur may be heard at this time (presystolic accentuation). Educational objective: Aortic regurgitation causes a decrescendo diastolic murmur with maximal intensity occurring just after closure of the aortic valve, when the pressure gradient between the aorta and left ventricle is the highest. The pressure tracing for aortic regurgitation is characterized by loss of the aortic dicrotic notch, steep diastolic decline in aortic pressure, and high-peaking systolic pressures. __________ References: The rational clinical examination. Does this patient have aortic regurgitation? (http://www.ncbi.nlm.nih.gov/pubmed/10376577)

A 52-Year-Old Man Comes to the Office Due to a 2-Week