A 75-year-old man comes to the office due to worsening dyspnea and fatigue on exertion over the last 6 months. Recently, he has had severe lightheadedness during physical activity. Blood pressure is 125/65 mm Hg and pulse is 65/min and regular. Physical examination reveals a harsh ejection-type systolic murmur at the base of the heart radiating to the neck. The second heart sound is diminished in intensity. A fourth heart sound is heard at the cardiac apex. Which of the following is the most likely cause of this patient's heart condition?

Question

A 75-year-old man comes to the office due to worsening dyspnea and fatigue on exertion over the last 6 months.  Recently, he has had severe lightheadedness during physical activity.  Blood pressure is 125/65 mm Hg and pulse is 65/min and regular.  Physical examination reveals a harsh ejection-type systolic murmur at the base of the heart radiating to the neck.  The second heart sound is diminished in intensity.  A fourth heart sound is heard at the cardiac apex.  Which of the following is the most likely cause of this patient's heart condition?

Quizplus · Accepted Answer

This patient's presentation (fatigue, progressive dyspnea, presyncope with exertion, and a cardiac murmur) is suggestive of aortic valve stenosis (AS).xa0 In AS, the heart is unable to adequately increase cardiac output during exercise, causing pulmonary vascular congestion and reduced mean arterial pressure.xa0 These changes cause dyspnea and lightheadedness, respectively.xa0 AS can also chronically lower cardiac output, causing an increased tendency toward fatigue in general.xa0 AS murmur is usually a harsh ejection-type systolic murmur heard best at the base of the heart in the "aortic area" (second right intercostal space) with radiation to the carotid arteries.xa0 Second heart sound (S2) is diminished in intensity due to reduced mobility of the aortic leaflets, and a fourth heart sound (S4) may be heard due to decreased compliance of the hypertrophic myocardium. Calcific degeneration of the trileaflet aortic valve is the most common cause of valvular AS in developed nations.xa0 AS is characterized by progressive aortic valve leaflet thickening and calcification, leading to restricted leaflet excursion and mobility.xa0 Congenital heart disease, such as bicuspid aortic valve, can also lead to AS due to accelerated valve degeneration.xa0 On the other hand, rheumatic valve disease is a common cause of AS in developing nations and is characterized by fusion of valve commissures due to repetitive inflammation (Choice B).xa0 Rheumatic valve disease usually presents at an earlier age and involves the mitral valve as well. (Choice C)xa0 Hypertrophy of the basal interventricular septum with subaortic obstruction is the pathophysiologic process in patients with hypertrophic cardiomyopathy.xa0 Physical examination reveals a harsh crescendo-decrescendo murmur heard best at the apex and lower sternal border.xa0 The murmur does not radiate to the neck, and S2 is usually normal. (Choice D)xa0 Infective endocarditis can lead to aortic regurgitation (AR) due to inadequate coaptation of the aortic leaflets.xa0 AR murmur is an early, decrescendo, high-pitched, blowing diastolic murmur that begins immediately after A2.xa0 It is best heard along the left sternal border at the third and fourth intercostal spaces. (Choice E)xa0 Myxomatous degeneration of the mitral valve leaflets leads to mitral valve prolapse.xa0 Cardiac auscultation usually reveals a non-ejection click and mid-to-late systolic murmur of mitral regurgitation. Educational objective: Calcific degeneration of the trileaflet aortic valve is the most common cause of aortic stenosis (AS) in developed nations.xa0 AS is characterized by progressive aortic valve leaflet thickening and calcification, leading to restricted leaflet excursion and mobility.xa0 AS murmur is usually a harsh ejection-type systolic murmur heard best at the base of the heart in the "aortic area" (second right intercostal space) with radiation to the carotid arteries.

A 75-Year-Old Man Comes to the Office Due to Worsening