A 33-year-old man comes to the office due to fatigue and decreased exercise tolerance over the past 6 months. The patient was diagnosed with infective endocarditis in the setting of intravenous drug use a year ago and completed a course of antibiotic therapy. He has not used drugs since then. The patient has no other medical problems and takes no medications. A cardiac murmur is heard on auscultation. Both carotid arteries demonstrate a rapid rise and fall of the arterial pulse. Partial compression of the femoral arteries by the stethoscope elicits a systolic-diastolic bruit. Which of the following sets of pressure findings is most likely to be observed during cardiac catheterization of this patient?

Question

Quizplus · Accepted Answer

11ec160b_3c85_b68b_9249_03157564f626_MD0001_00 This patient's presentation is consistent with aortic regurgitation (AR), which likely developed as a complication of infective endocarditis. AR is characterized by a rapid loss of aortic pressure during diastole due to backflow of blood into the left ventricle. The left ventricle becomes dilated with an increase in end-diastolic volume and undergoes eccentric hypertrophy that allows for a compensatory increase in stroke volume and cardiac output. The result of these effects is a characteristic high-amplitude, rapid rise-rapid fall pulsation with each ventricular contraction that manifests as widened pulse pressure, rapid distension and collapse of the carotid arteries (Corrigan sign), and a "to-and-fro" bruit appreciated over the femoral arteries (Duroziez sign). The hemodynamic changes in AR are evident on cardiac catheterization and include reduced aortic diastolic pressure and elevated left ventricular (LV) diastolic pressure due to backflow of blood during diastole. In addition, aortic and LV systolic pressures are increased due to high stroke volume and a compensatory increase in cardiac contractility. (Choice A) LV systolic pressure that is higher than aortic systolic pressure is consistent with aortic stenosis. Patients with aortic stenosis have weak and delayed pulses (pulsus parvus et tardus) and pulse pressure may be reduced due to restricted stroke volume. The LV often undergoes concentric hypertrophy (wall-thickening) due to pressure overload. (Choice B) These are normal LV and aortic pressure findings on cardiac catheterization. (Choice C) Normal LV systolic and aortic pressures but elevated LV end-diastolic pressure is consistent with compensated heart failure. The left ventricle often undergoes eccentric hypertrophy due to volume overload. (Choice E) Elevated aortic pressures with no systolic pressure gradient across the aortic valve and normal LV diastolic pressure is consistent with systemic hypertension. Concentric hypertrophy may develop due to pressure overload. Educational objective: Aortic regurgitation causes a rapid fall in aortic pressure during diastole with an increase in left ventricular end-diastolic volume and a compensatory increase in stroke volume. These hemodynamic changes create characteristic pressure changes, including reduced aortic diastolic pressure, increased aortic systolic pressure, and increased left ventricular diastolic and systolic pressures. __________ References: Clinical practice. Aortic regurgitation. (http://www.ncbi.nlm.nih.gov/pubmed/15470217)

A 33-Year-Old Man Comes to the Office Due to Fatigue