Cardiology · Valvular Heart Disease
The facts most likely to be tested
The classic clinical triad of Aortic Stenosis consists of exertional syncope, angina, and dyspnea (SAD).
Physical examination reveals a systolic crescendo-decrescendo murmur heard best at the right upper sternal border that radiates to the carotids.
The pulse character in severe Aortic Stenosis is described as pulsus parvus et tardus, meaning a weak and delayed carotid upstroke.
The murmur intensity of Aortic Stenosis decreases with Valsalva maneuver and handgrip exercise.
Echocardiography is the gold standard diagnostic test to confirm the diagnosis and assess the aortic valve area and mean pressure gradient.
Surgical Aortic Valve Replacement (SAVR) or Transcatheter Aortic Valve Replacement (TAVR) is the definitive treatment for symptomatic severe aortic stenosis.
Bicuspid aortic valve is the most common cause of Aortic Stenosis in patients younger than 70 years of age.
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A 72-year-old male presents to the clinic complaining of lightheadedness and chest tightness during his daily morning walks. On physical exam, he has a harsh systolic crescendo-decrescendo murmur heard at the right second intercostal space that radiates to the neck. Carotid palpation reveals a weak and delayed upstroke. He has no history of rheumatic fever, but his father had a heart valve replacement at age 55.
What is the most appropriate next step in the management of this patient?
Transthoracic echocardiogram
The patient presents with the classic triad of symptomatic aortic stenosis (syncope, angina, murmur). An echocardiogram is required to confirm the diagnosis and quantify the severity of the stenosis.
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Etiology / Epidemiology
Most common in elderly due to calcific degeneration; younger patients often have a congenital bicuspid valve.
Clinical Manifestations
Classic triad: Angina, Syncope, Dyspnea (SAD). Murmur is a harsh systolic crescendo-decrescendo at the right upper sternal border.
Diagnosis
Transthoracic echocardiogram is the gold standard. Mean transvalvular gradient >40 mmHg or valve area <1.0 cm² confirms severe disease.
Treatment
Surgical aortic valve replacement (SAVR) is the definitive treatment. Avoid vasodilators in severe symptomatic cases.
Prognosis
Once symptoms develop, survival is poor without intervention. 3-year mortality is high if left untreated.
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Epidemiology & Etiology
In patients >65, calcific degeneration is the primary cause. In patients <70, a congenital bicuspid valve is the most frequent etiology. Rheumatic heart disease remains a significant cause in developing nations.
Pertinent Anatomy
The aortic valve typically has three leaflets. Stenosis creates a fixed left ventricular outflow tract (LVOT) obstruction, forcing the heart to generate high pressures to maintain cardiac output.
Pathophysiology
Chronic pressure overload leads to concentric left ventricular hypertrophy (LVH) to maintain wall stress. Eventually, the ventricle fails, leading to diastolic dysfunction and reduced coronary perfusion. This creates a fixed cardiac output state, limiting the ability to increase flow during exertion.
Clinical Manifestations
Patients present with the SAD triad: Syncope, Angina, and Dyspnea. Physical exam reveals a harsh systolic crescendo-decrescendo murmur radiating to the carotids and a pulsus parvus et tardus (weak and delayed carotid upstroke). Sudden cardiac death is a major risk in symptomatic patients.
Diagnosis
Transthoracic echocardiogram is the diagnostic test of choice. Severe stenosis is defined by a valve area <1.0 cm², a mean gradient >40 mmHg, or a peak velocity >4.0 m/s. Exercise stress testing is contraindicated in symptomatic patients.
Treatment
Surgical aortic valve replacement (SAVR) or Transcatheter aortic valve replacement (TAVR) are the only definitive treatments. Medical management is palliative; avoid nitrates and ACE inhibitors in severe cases as they can cause precipitous hypotension. Patients must be monitored with serial echos.
Prognosis
Prognosis is dismal once symptoms appear; average survival is 2-3 years for heart failure, 3 years for syncope, and 5 years for angina. Annual follow-up is required for asymptomatic patients with mild-to-moderate disease.
Differential Diagnosis
Hypertrophic Cardiomyopathy: Murmur intensity increases with Valsalva
Mitral Regurgitation: Holosystolic murmur at the apex
Aortic Sclerosis: No LVOT obstruction or symptoms
Pulmonic Stenosis: Murmur heard best at the left upper sternal border
Mitral Valve Prolapse: Mid-systolic click