A 73-year-old man is evaluated for exertional dyspnea. His exercise tolerance has decreased over the last year, and he can barely walk 2-3 blocks without stopping. The patient also reports occasional episodes of lightheadedness and palpitations. He has had no chest pain or syncope. He was diagnosed with hypertension in the past but does not take any medications. Physical examination reveals a cardiac murmur. The patient is referred to a cardiologist for further evaluation. Cardiac catheterization is performed, and the findings are shown in the image below. Which of the following points most likely corresponds to the peak murmur intensity in this patient?

Question

A 73-year-old man is evaluated for exertional dyspnea.  His exercise tolerance has decreased over the last year, and he can barely walk 2-3 blocks without stopping.  The patient also reports occasional episodes of lightheadedness and palpitations.  He has had no chest pain or syncope.  He was diagnosed with hypertension in the past but does not take any medications.  Physical examination reveals a cardiac murmur.  The patient is referred to a cardiologist for further evaluation.  Cardiac catheterization is performed, and the findings are shown in the image below.  Which of the following points most likely corresponds to the peak murmur intensity in this patient?

Quizplus · Accepted Answer

In the absence of any aortic valve pathology, the pressure in the aorta is similar to left ventricular pressure during systole. However, this patient's hemodynamic profile shows an abnormal pressure gradient between the left ventricular and aortic pressure tracings during systole (compare to normal), indicating significant aortic stenosis (AS). The intensity of the murmur of AS is directly related to the magnitude of the left ventricle to aorta pressure gradient. The maximum pressure difference between the left ventricular and aortic pressure tracings is noted at point B and corresponds to the peak intensity of a cardiac murmur during auscultation. (Choices A and C) The murmur of AS is a systolic ejection-type crescendo-decrescendo murmur that starts after the first heart sound following the opening of the aortic valve (point A). It typically ends before the A2 component of the second heart sound (point C). At points A and C, the left ventricular and aortic pressures are nearly equal with no or minimal flow across the aortic valve, and the murmur of AS would not be appreciated. (Choices D and E) These points occur during diastole, when the aortic valve is closed and the mitral valve is open. There is no abnormally elevated pressure gradient between the left atrium and left ventricle. This is consistent with normal, unobstructed diastolic filling of the left ventricle, and no murmur would be heard during diastole. Educational objective: The murmur of aortic stenosis (AS) is a systolic ejection-type, crescendo-decrescendo murmur that starts after the first heart sound and typically ends before the A2 component of the second heart sound. The intensity of the murmur is proportional to the magnitude of the left ventricle to aorta pressure gradient during systole. __________ References: The patient with a systolic murmur: severe aortic stenosis may be missed during cardiovascular examination. (http://www.ncbi.nlm.nih.gov/pubmed/11029480)

A 73-Year-Old Man Is Evaluated for Exertional Dyspnea