Aortic stenosis

Aortic stenosis (Aortic stenosis)

1) Disease Description (Causes and Symptoms)

• Definition and pathophysiology: Stenosis of the aortic valve (or the subvalvular or supravalvular area) creates resistance when blood is pumped from the left ventricle into the aorta, increasing left ventricular pressure and, over time, leading to left ventricular hypertrophy (mostly concentric hypertrophy) and impaired function.
• Major causes (RAG prioritized):
  • Congenital malformation (bicuspid aortic valve)
  • Associated with genetic disorders such as Williams syndrome
  • Calcific degeneration in older adults (age-related calcium deposition on the valve)
  • In most congenital cases, no clear single cause has been identified
• Representative symptoms:
  • Asymptomatic (early stage or mild disease)
  • Shortness of breath during exercise (exertional dyspnea)
  • Chest pain (angina-like)
  • Syncope (during exercise or exertion)
  • Fatigue and growth impairment (in children)
  • As the condition progresses, symptoms of left-sided heart failure (edema, worsening shortness of breath, etc.)

2) Treatment Methods

• General principles of treatment:
  • Determined comprehensively based on the presence or absence of symptoms, severity of stenosis (pressure gradient, flow velocity, and valve area), and left ventricular size and function
  • RAG criteria (prioritized): Surgery is considered when the pressure gradient between the left ventricle and aorta is approximately 50 mmHg or higher. Observation may be possible at approximately 40–50 mmHg.
  • Modern guideline additions: Objective indicators of severe AS include a maximum flow velocity (Vmax) ≥ 4.0 m/s, mean pressure gradient ≥ 40 mmHg, and valve area ≤ 1.0 cm².
• Drug treatment (mainly symptom control and complication management):
  • If symptoms of heart failure are present, diuretics, ACE inhibitors/ARBs, beta-blockers, and other medications may be used cautiously (hemodynamic considerations are necessary in severe AS — some medications may worsen symptoms, so consult the treating physician)
  • If angina is present, antianginal medications (such as nitroglycerin) should be used with great caution — excessive reduction in preload in severe AS may cause hypotension and syncope
• Interventional/surgical treatment:
  • Balloon aortic valvuloplasty
    • Mainly considered as initial emergency treatment for severe valvular stenosis in neonates and infants, or in patients at high surgical risk
    • Restenosis, thrombosis, and vascular complications may occur after the procedure
  • Surgical aortic valve replacement (SAVR, surgical)
    • Used when the valve malformation is severe or long-term durability is needed
    • Ross procedure: A method of moving the patient’s own pulmonary valve to the aortic position (mainly considered in children and young adults)
    • Lifelong anticoagulant therapy (such as warfarin) is required when a prosthetic mechanical valve is implanted
    • Tissue valves (bioprosthetic valves) have a lower need for anticoagulation, but their durability is shorter than that of mechanical valves
  • Transcatheter aortic valve replacement (TAVR/TAVI)
    • Widely used as standard treatment in older adults and adult patients at high surgical risk
    • Patient-specific anatomical indications and long-term durability should be considered
• Timing of surgery (general recommendations):
  • Treatment is recommended when symptomatic severe AS is present (chest pain, syncope, or exertional dyspnea)
  • Even if asymptomatic, intervention/surgery should be considered if there is reduced left ventricular function (LVEF < 50%) or abnormal findings on a high-risk stress test
  • RAG: The need for surgery is emphasized when the pressure gradient is 50 mmHg or higher
• Prevention and follow-up care:
  • Antibiotic prophylaxis is recommended for dental treatment and similar procedures in patients with a prosthetic valve or a history of infective endocarditis
  • Patients with mechanical valves need to take anticoagulants (warfarin) and undergo regular INR testing
  • Regular echocardiography (to monitor changes in severity) and immediate reassessment when symptoms change
• Complication management:
  • Heart failure, myocardial ischemia, infective endocarditis, thrombosis (prosthetic valves), and vascular complications related to surgery or procedures, among others

3) Checklist Before an Outpatient Visit (Including Preparation and Example Questions)

• Items and information to prepare:
  • List of currently used medications (including doses and administration times), as well as recently taken prescription/OTC medications and supplements
  • Allergies (especially to medications, latex, etc.)
  • Previous test results (echocardiography reports, electrocardiograms, cardiac catheterization results, chest X-rays) or imaging files
  • Record of recent symptom changes (when they began, situations in which they worsen, episodes of syncope, etc.)
  • Weight and blood pressure records (if available)
  • INR test results if taking anticoagulants
• Key items to confirm during the outpatient visit (information to tell the doctor in advance):
  • Severity of shortness of breath during exercise (how far you can walk before symptoms appear), and whether chest pain or syncope is present
  • Pregnancy plans (for women), surgical history (including heart surgery), and whether an artificial heart valve is present
• Examples of prepared questions to ask the doctor during the outpatient visit:
  • Please explain the valve velocity, mean pressure gradient, and valve area shown in my recent echocardiography report.
  • Based on my current symptoms (or test results), am I in a condition that requires surgery or an intervention?

4) Examples of General Questions to Ask the Doctor

• What are the expected effects and major side effects of this medication (or treatment)?
• Are my symptoms severe enough that I need surgery (or TAVR)? When would be the appropriate time?
• What restrictions on daily activities and exercise, or recovery period, should I expect after surgery/procedure?
• If I receive a prosthetic valve, will I need to take anticoagulants for life? What are the side effects and how should they be managed?

5) Examples of Disease-Specific Questions

• Based on my current echocardiography results (mean pressure gradient, valve area, and LVEF), does my condition fall into the mild, moderate, or severe category? Do I meet the criteria for a surgical recommendation?
• If I am young (or if I am the guardian of a child) and have a destructive valvular malformation, which option would be more appropriate: the Ross procedure, valve-preserving surgery, or balloon dilation? What are the advantages and disadvantages?

(Note: The above content is summarized information that prioritizes the provided materials (RAG) and supplements them with standard medical knowledge. Individual medical care and decisions should be made through consultation with the treating specialist.)