A 52-year-old man comes to the office with concerns about a "heart problem." Three years ago, the patient was told during a routine physical examination that he had a heart murmur. Currently, he has no specific complaints, but he mentions that he has become tired more easily in the past year. He has no chest pain or lower extremity swelling or significant medical history. The patient was healthy as a child and received all his childhood vaccinations. Blood pressure is 145/90 mm Hg and pulse is 80/min and regular. Physical examination reveals a holosystolic murmur best heard at the apex of the heart that radiates to the axilla. The lungs are clear on auscultation and abdominal examination is unremarkable. Which of the following is the best indicator of the severity of this patient's valve disease?

Question

A 52-year-old man comes to the office with concerns about a "heart problem."  Three years ago, the patient was told during a routine physical examination that he had a heart murmur.  Currently, he has no specific complaints, but he mentions that he has become tired more easily in the past year.  He has no chest pain or lower extremity swelling or significant medical history.  The patient was healthy as a child and received all his childhood vaccinations.  Blood pressure is 145/90 mm Hg and pulse is 80/min and regular.  Physical examination reveals a holosystolic murmur best heard at the apex of the heart that radiates to the axilla.  The lungs are clear on auscultation and abdominal examination is unremarkable.  Which of the following is the best indicator of the severity of this patient's valve disease?

Quizplus · Accepted Answer

A holosystolic murmur at the apex with radiation to the axilla is consistent with mitral regurgitation (MR). The murmur is generated by regurgitant blood flow from the left ventricle back to the left atrium during systole. This results in elevated pressure and blood volume in the left atrium, which increases the amount of blood reentering the left ventricle during diastole; an audible S3 gallop occurs when the left ventricle is unable to accommodate the excess blood flow. An S3 is generated by the sudden cessation of blood flow into the left ventricle during the passive filling phase of diastole. A higher volume of blood flow or a more dilated left ventricle is more likely to produce an S3, and although an S3 can be a normal finding in healthy young adults, it is usually a pathologic finding in older adults that is classically associated with heart failure. In patients with MR, an S3 is the best indicator of severe MR with left-sided volume overload; the absence of an S3 can be used to exclude severe chronic MR. (Choice B) An S4 is a low-frequency diastolic sound that occurs during the atrial kick of ventricular diastole, and it reflects blood colliding with a stiff ventricular wall. It often indicates pathology such as hypertrophic cardiomyopathy or concentric left ventricular hypertrophy (eg, due to hypertension or aortic stenosis). (Choice C) A mid-systolic click is characteristic of mitral valve prolapse. It is caused by sudden tensing of the chordae tendineae as they are pulled taut by the valve leaflets ballooning into the left atrium. The timing of the click varies with left ventricular volume; it occurs earlier in systole with physical maneuvers that decrease left ventricular volume. (Choice D) An opening snap is an early diastolic sound heard after S2 in patients with mitral or tricuspid stenosis. The S2-to-opening snap interval is the time between the closure of the aortic valve and the abrupt halting of leaflet motion during opening of a stenotic mitral valve; a shorter S2-to-opening snap interval is indicative of more severe mitral stenosis. (Choice E) Pulmonic valve stenosis delays pulmonic valve closure leading to widened splitting of S2. The splitting is further accentuated by the increase in venous return to the right side of the heart that occurs with inspiration. Educational objective: Patients with severe mitral regurgitation develop left-sided volume overload with an S3 gallop due to the large volume of regurgitant flow reentering the ventricle during mid-diastole. The absence of an S3 gallop excludes severe chronic MR. __________ References: Diastolic properties of the left ventricle in normal adults and in patients with third heart sounds. (http://www.ncbi.nlm.nih.gov/pubmed/6713611)

A 52-Year-Old Man Comes to the Office with Concerns About