A 32-year-old primigravida at 28 weeks gestation is referred from the obstetrics clinic due to shortness of breath. She is an immigrant from Mexico. Her pregnancy has thus far been uncomplicated except for nausea in the first trimester. Over the last four weeks, she has been feeling tired and becomes short of breath with activities that she was previously able to perform with ease, such as walking several blocks or climbing stairs on the subway. She denies chest pain, wheezing, cough, or nocturnal symptoms. Her other medical problems include obesity and mild intermittent asthma. Cardiac auscultation findings can be heard in the exhibit.
Which of the following is the most likely diagnosis?

Question

A 32-year-old primigravida at 28 weeks gestation is referred from the obstetrics clinic due to shortness of breath.  She is an immigrant from Mexico.  Her pregnancy has thus far been uncomplicated except for nausea in the first trimester.  Over the last four weeks, she has been feeling tired and becomes short of breath with activities that she was previously able to perform with ease, such as walking several blocks or climbing stairs on the subway.  She denies chest pain, wheezing, cough, or nocturnal symptoms.  Her other medical problems include obesity and mild intermittent asthma.  Cardiac auscultation findings can be heard in the exhibit.
Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

Cardiac auscultation reveals a loud first heart sound (S1). Following the second heart sound (S2), there is a high frequency, early diastolic sound (opening snap), with a trailing mid-diastolic murmur due to turbulent flow across the atrioventricular valves. These are the characteristic auscultatory findings of mitral stenosis. The murmur of mitral stenosis is described as a low pitched diastolic rumble, which is heard best at the apex using the bell of the stethoscope while the patient lies on their left side with their breath held at end expiration. As mitral stenosis becomes more severe, the opening snap (OS) occurs earlier after S2 (shorter A2-OS interval). In patients in sinus rhythm, there is also an increase in the intensity of the diastolic murmur during atrial contraction, a phenomenon termed "presystolic accentuation." (Choice A) Aortic stenosis in younger patients is typically due to the presence of a bicuspid aortic valve. Cardiac auscultation typically reveals a prominent systolic ejection click after S1 followed by a mid-systolic murmur. (Choice C) Normal pregnancy is associated with an increase in blood volume and cardiac output. This can result in a short and soft systolic ejection murmur due to increased flow across the normal aortic and pulmonary valves. (Choice D) This patient has the classic cardiac auscultation findings of mitral stenosis. Peripartum cardiomyopathy, by definition, has to meet certain criteria. certain criteria (Choice E) A ventricular septal defect causes a loud holosystolic murmur along with a palpable thrill. It is best appreciated along the left sternal border over the third or fourth intercostal space. Educational objective: Cardiac auscultation findings in patients with mitral stenosis include an accentuated first heart sound (S1), an opening snap after the second heart sound (S2), and a mid-diastolic murmur or rumble with presystolic accentuation. The diastolic murmur of mitral stenosis is best heard at the cardiac apex using the bell of stethoscope while the patient lies in the left lateral decubitus position with their breath held at end expiration. __________ References: On the mechanism of accentuation of the first heart sound in mitral stenosis. (http://www.ncbi.nlm.nih.gov/pubmed/6723317)

A 32-Year-Old Primigravida at 28 Weeks Gestation Is Referred from the Obstetrics