Arteriovenous fistula dysfunction

1) Disease Description (Causes and Symptoms)

• Definition: Aortic valve insufficiency is a condition in which the aortic valve does not close completely, causing blood to flow backward from the aorta into the left ventricle during diastole (the ventricular filling phase).
• Pathophysiology summary: As the regurgitant volume increases, the left ventricle becomes overloaded, resulting in volume overload (eccentric hypertrophy). Over time, this may progress to left ventricular dilatation and reduced left ventricular systolic function. In acute severe cases, the left ventricle has no time to adapt, and left ventricular diastolic pressure rises rapidly, leading to pulmonary edema and heart failure.
• Main causes: Degenerative valve changes (aging), congenital bicuspid aortic valve, aortic root dilatation (connective tissue diseases such as Marfan syndrome), aortic dissection or dilatation, infective endocarditis, and, rarely, rheumatic changes.
• Main symptoms: Asymptomatic (early stage), easy fatigue and shortness of breath during exercise, shortness of breath at rest (as the condition progresses), chest pain (angina-like), paroxysmal nocturnal dyspnea, cough and sputum, and rarely syncope. In acute severe cases, acute dyspnea, pulmonary edema, and hypotension may occur.
• Physical examination findings (for reference): Wide pulse pressure, a bounding pulse (e.g., Corrigan pulse), a diastolic decrescendo murmur (tending to diminish rapidly), and other changes in accessory heart sounds.

2) Treatment Methods and Precautions

• General principles
  • Chronic mild to moderate disease: If there are no symptoms, regularly monitor changes in left ventricular size and systolic function through follow-up examinations (echocardiography).
  • Valve surgery (replacement or repair) is recommended in cases of severe disease, the development of symptoms, or left ventricular dilatation or reduced systolic function exceeding the threshold criteria.
  • Acute severe disease: Immediate surgery (usually urgent valve replacement) after emergency stabilization, including hemodynamic support and vasodilation.
• Drug treatment (symptomatic and supportive)
  • Blood pressure control and reduction of preload/afterload: ACE inhibitors/ARBs and calcium channel blockers (e.g., nifedipine) may be used to control symptoms or delay surgery and reduce risk, but they are not definitive treatments. In acute severe cases, IV vasodilators (e.g., sodium nitroprusside) may lower afterload and improve the condition before surgery.
  • Diuretics, oxygen, and mechanical ventilation are supportive treatments for pulmonary edema and acute heart failure.
  • Appropriate antibiotic treatment in cases of an infectious cause.
• Surgical treatment
  • Valve repair: Considered when possible, such as when the valve structure is preserved and correction can be performed together with treatment of an aortic root problem.
  • Valve replacement: Performed in most patients with severe disease. The choice between a mechanical valve (semi-permanent but requiring lifelong anticoagulation) and a tissue valve (less need for anticoagulation but limited durability) takes into account age, plans for pregnancy, indications for and risks of anticoagulation, and other factors.
  • Percutaneous treatment (such as TAVR): Its application to pure aortic regurgitation is currently limited, although it may be considered in some high-risk patients.
• Self-care and lifestyle management (including before and after surgery)
  • Strict blood pressure control, a low-salt diet, weight management, regular aerobic exercise (avoid overexertion), and no smoking or excessive alcohol consumption.
  • Prevention of infective endocarditis during dental or surgical procedures: Antibiotic prophylaxis may be recommended during dental treatment for people with prosthetic valves or a history of endocarditis (follow the doctor's instructions).
  • Patients with mechanical valves: Lifelong use of anticoagulants (such as warfarin) and regular INR monitoring are necessary.
• Complications and precautions
  • As the condition progresses, possible complications include reduced left ventricular systolic function, heart failure, pulmonary edema, infective endocarditis, arrhythmia, and sudden death.
  • Delayed surgery may result in a poor prognosis because reduced left ventricular function may not recover even after surgery.

3) Checkpoints Before an Outpatient Visit (Including items to bring and examples of questions the doctor may ask)

• Items/documents to bring
  • List of current medications (including prescriptions, OTC medications, and herbal medicines) and allergy records
  • Results and dates of previous echocardiography examinations (if possible, bring the images and reports)
  • Recent records of changes in blood pressure and weight (self-measured values)
  • Records of symptom changes (whether shortness of breath is present, when it occurs, triggering factors, chest pain, syncope, etc.)
  • History of surgery, hospitalization, or bleeding; if currently taking anticoagulants, recent INR results
  • Recent dental procedures or infection-related procedures
• Questions the doctor is likely to ask during the outpatient visit (examples)
  • "When did your symptoms start, and how have they changed?"
  • "Do you become short of breath or have difficulty breathing during exercise? Does this also happen at rest?"
  • "Have you recently gained weight suddenly or developed swelling in your ankles or legs?"
  • "What medications are you currently taking, and are you taking blood pressure medication?"

4) Examples of General Questions to Ask the Doctor

• "Based on my current echocardiography results, how severe is my valve dysfunction? Do I need surgery?"
• "What are the expected side effects and precautions for this medication (e.g., an ACE inhibitor or anticoagulant)?"
• "Among the surgical options (replacement versus repair), which do you recommend for me, and what is the basis for that recommendation?"
• "If I need to take anticoagulants, what should I be careful about in daily life (exercise, diet, and dental treatment)?"
• "How often should I have follow-up examinations? What should I do immediately if my condition worsens urgently?"

5) Examples of Disease-Specific Questions (1–2 specialized questions)

• "What are my recent echocardiography measurements for left ventricular internal diameter (LVEDD and LVESD) and left ventricular ejection fraction (EF)? Do I currently meet the indications for surgery (e.g., exceeding the LV threshold or having a reduced EF)?"
• "If I am planning to become pregnant, would a tissue valve or a mechanical valve be more suitable for me when undergoing valve surgery? What would the anticoagulation management plan be?"