A 72-year-old female with no significant past medical histor…

A 72-year-old female with no significant past medical history passes out while exercising. She has intermittent exertional chest pains and dyspnea on exertion as well. Her physical examination reveals a III/VI late-peaking crescendo-decrescendo murmur at the right upper sternal border and a III/VI holosystolic murmur at the apex. Her S2 heart sound is very soft and her carotid upstroke is weak and delayed. Which of the following is most likely causing her symptoms?

A patient with a systolic crescendo-decrescendo murmur under…

A patient with a systolic crescendo-decrescendo murmur undergoes cardiac catheterization. The peak LV pressure is 160 mmHg. The patient’s diastolic BP is 100 mmHg and their mean arterial pressure is 110 mmHg. What is the gradient across the aortic valve (in mm Hg)?

Using the Nernest equation and typical concentrations of pot…

Using the Nernest equation and typical concentrations of potassium inside and outside of cells, the predicted Em (resting membrane potential) is -96 mV. However, the measured Em in cardiac myocytes is -90 mV. Why is the actual Em different from the predicted Em based upon potassium?