A 58-year-old female presents to her primary care physician with complaints of chest pain and palpitations. A thorough past medical history reveals a diagnosis of rheumatic fever during childhood. Echocardiography is conducted and shows enlargement of the left atrium and narrowing of the mitral valve opening. Which of the following should the physician expect to hear on cardiac auscultation?

Continuous, machine-like murmur

High-pitched, blowing decrescendo murmur in early diastole

A 2-year-old girl is brought to the physician by her mother for a well-child examination. Cardiac auscultation is shown. When she clenches her fist forcefully for a sustained time, the intensity of the murmur increases. Which of the following is the most likely cause of this patient's auscultation findings?

Defect in the ventricular septum

Failure of the ductus arteriosus to close

Fusion of the right and left coronary leaflets

A 72-year-old man presents to his primary care physician for a general checkup. The patient works as a farmer and has no concerns about his health. He has a past medical history of hypertension and obesity. His current medications include lisinopril and metoprolol. His temperature is 99.5°F (37.5°C), blood pressure is 177/108 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for a murmur after S2 over the left sternal border. The patient demonstrates a stable gait and 5/5 strength in his upper and lower extremities. Which of the following is another possible finding in this patient?

Murmur that radiates to the carotids

Wedge pressure lower than expected

Rumbling heard at the cardiac apex

Audible click heard at the cardiac apex

A 61-year-old man comes to the physician because of a 3-month history of fatigue and progressively worsening shortness of breath that is worse when lying down. Recently, he started using two pillows to avoid waking up short of breath at night. Examination shows a heart murmur. A graph with the results of cardiac catheterization is shown. Given this patient's valvular condition, which of the following murmurs is most likely to be heard on cardiac auscultation?

High-pitched, holosystolic murmur that radiates to the axilla

High-frequency, diastolic murmur heard best at the 2nd left intercostal space

Harsh, late systolic murmur that radiates to the carotids

Blowing, early diastolic murmur heard best at the Erb point

Rumbling, delayed diastolic murmur heard best at the cardiac apex

A 47-year-old man presents for a routine physical examination as part of an insurance medical assessment. He has no complaints and has no family history of cardiac disease or sudden cardiac death. His blood pressure is 120/80 mm Hg, temperature is 36.7°C (98.1°F), and pulse is 75/min and is regular. On physical examination, he appears slim and his cardiac apex beat is of normal character and non-displaced. On auscultation, he has a midsystolic click followed by a late-systolic high-pitched murmur over the cardiac apex. On standing, the click and murmur occur earlier in systole, and the murmur is of increased intensity. While squatting, the click and murmur occur later in systole, and the murmur is softer in intensity. Echocardiography of this patient will most likely show which of the following findings?

Prolapse of a mitral valve leaflet of ≥2 mm above the level of the annulus in systole

Left atrial mass arising from the region of the septal fossa ovalis

Doming of the mitral valve leaflets in diastole

Retrograde blood flow into the right atrium

High pressure gradient across the aortic valve

A 32-year-old male presents for a new patient visit. He states that he is in good health but has had decreasing exercise tolerance and increased levels of shortness of breath over the past 5 years. He believed that it was due to aging; he has not seen a doctor in 10 years. On auscultation, you note an early diastolic decrescendo blowing murmur that radiates along the left sternal border. In the United States, what is the most likely cause of this patient's condition?

Congenital bicuspid aortic valve

A 43-year-old woman presents to the emergency department complaining of palpitations, dry cough, and shortness of breath for 1 week. She immigrated to the United States from Korea at the age of 20. She says that her heart is racing and she has never felt these symptoms before. Her cough is dry and is associated with shortness of breath that occurs with minimal exertion. Her past medical history is otherwise unremarkable. She has no allergies and is not currently taking any medications. She is a nonsmoker and an occasional drinker. She denies illicit drug use. Her blood pressure is 100/65 mm Hg, pulse is 76/min, respiratory rate is 23/min, and temperature is 36.8°C (98.2°F). Her physical examination is significant for bibasilar lung crackles and a non-radiating, low-pitched, mid-diastolic rumbling murmur best heard at the apical region. In addition, she has jugular vein distention and bilateral pitting edema in her lower extremities. Which of the following best describes the infectious agent that led to this patient’s condition?

A bacterium that induces complete lysis of the red cells of a blood agar plate with an oxygen-sensitive cytotoxin

A bacterium that induces partial lysis of red cells with hydrogen peroxide

A bacterium that requires an anaerobic environment to grow properly

A bacterium that does not lyse red cells

A bacterium that induces heme degradation of the red cells of a blood agar plate

Valvular heart disease for USMLE Step 1: High-Yield Pathology Lessons

Aortic Stenosis & Regurgitation - Gate Problems

Aortic Stenosis (AS): Obstruction of LV outflow.
- Causes: Senile calcification (>60 yrs), bicuspid aortic valve (<60 yrs), rheumatic heart disease.
- Murmur: Systolic crescendo-decrescendo, radiates to carotids.
- Symptoms: 📌 SAD Triad: Syncope, Angina, Dyspnea.
- Hemodynamics: ↑LV pressure, concentric hypertrophy, narrowed pulse pressure.
Aortic Regurgitation (AR): Retrograde flow into LV.
- Causes: Aortic root dilation (Marfan, syphilis), endocarditis, rheumatic fever.
- Murmur: Diastolic decrescendo, high-pitched, blowing.
- Signs: Wide pulse pressure, water-hammer pulse, de Musset's sign (head bobbing).

⭐ Gallavardin phenomenon: In AS, the murmur's musical component can radiate to the apex, mimicking mitral regurgitation.

Pressure-volume loops for valvular heart disease

Mitral Stenosis & Regurgitation - Doorway Drama

Mitral Stenosis (MS): Valve won't open
- Etiology: Rheumatic heart disease is the primary cause.
- Auscultation: Mid-diastolic rumble with a preceding opening snap, best heard at the apex.
- Pathophysiology: ↑ LA pressure → LA enlargement → pulmonary hypertension & atrial fibrillation risk.
- 📌 Mnemonic: OS-DR (Opening Snap, Diastolic Rumble).
Mitral Regurgitation (MR): Valve won't close
- Etiology: Mitral valve prolapse, ischemic heart disease, infective endocarditis.
- Auscultation: Holosystolic (pansystolic) murmur, high-pitched, loudest at the apex, radiating to the axilla.
- Pathophysiology: LA & LV volume overload → LV dilation & failure.

⭐ In acute MR (e.g., papillary muscle rupture post-MI), the sudden volume load on a normal-sized LA/LV leads to prominent pulmonary edema and hypotension.

Echocardiogram showing mitral stenosis and regurgitation

Mitral Valve Prolapse & Right-Sided Lesions - Clicks & Whispers

Mitral Valve Prolapse (MVP):
- Sound: Mid-systolic click, late systolic murmur.
- Patho: Myxomatous degeneration → floppy leaflets balloon into LA.
- Maneuvers: ↓ Preload (Valsalva, standing) → earlier click, longer murmur. ↑ Preload/Afterload (squatting, handgrip) → later click, shorter murmur.
- Associated with Marfan & Ehlers-Danlos syndromes.

Mitral valve prolapse murmur changes with maneuvers

Right-Sided Murmurs:
- 📌 RILE: Right-sided murmurs ↑ with Inspiration.
- Tricuspid Regurgitation: Holosystolic murmur.
- Pulmonic Stenosis: Systolic ejection murmur.

⭐ Maneuver Paradox: The MVP murmur starts earlier and lasts longer with maneuvers that decrease preload (e.g., Valsalva, standing), unlike most other murmurs.

Murmur Maneuvers - The Sound Symphony

Inspiration: ↑ venous return → ↑ Right-sided murmurs (TS, TR).
- 📌 RILE: Right-sided Increase, Left-sided Expiration.
Valsalva / Standing (↓ Preload): ↓ most murmurs.
- Increases: HOCM, MVP.
Squatting (↑ Preload/Afterload): ↑ most murmurs (AS, MR).
- Decreases: HOCM, MVP.
Handgrip (↑ Afterload): ↑ regurgitant murmurs (AR, MR, VSD).
- Decreases: HOCM, AS.

⭐ HOCM & MVP are exceptions: their murmurs behave opposite to most others with preload changes (Valsalva/squatting).

Cardiac Murmurs: Type, Accentuation, and Location

High‑Yield Points - ⚡ Biggest Takeaways

Rheumatic fever is the primary cause of mitral stenosis.

Aortic stenosis presents with Syncope, Angina, and Dyspnea (SAD) on exertion.

Mitral regurgitation causes a holosystolic murmur that radiates to the axilla.

Aortic regurgitation has a blowing diastolic murmur and widened pulse pressure.

Mitral valve prolapse, the most common disorder, has a characteristic mid-systolic click.

IV drug use is a key risk for endocarditis, typically affecting the tricuspid valve.

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