Interrupted aortic arch

Disease Description (Causes and Symptoms)

• Definition summary: A condition in which the vessel between the aorta and pulmonary artery (the ductus arteriosus), which should close after birth, does not close normally and remains open (Patent ductus arteriosus, PDA).
• Pathophysiology: Increased pulmonary blood flow due to a left-to-right shunt → left ventricular overload and fluid overload. If left untreated for a long time, pulmonary vascular resistance may increase and pulmonary hypertension may progress, resulting in a right-to-left shunt (Eisenmenger phenomenon).
• Main causes (reflecting the information provided as a priority):
  • The cause is unknown in most cases. A genetic factor may be suspected based on family history.
  • It may be associated with genetic disorders such as Down syndrome.
  • Rubella infection during pregnancy and fetal exposure to alcohol or antiepileptic drugs (e.g., phenytoin) have been reported as risk factors.
  • Accounts for approximately 5–10% of all congenital heart diseases. (Provided data: incidence in males is approximately three times higher than in females.)
• Main symptoms:
  • Often asymptomatic (particularly with a small PDA).
  • A heart murmur resembling a continuous machinery sound (auscultation finding).
  • Growth retardation, frequent respiratory infections, and symptoms of heart failure (shortness of breath, fatigue)—mainly with a large PDA.
  • The timing of symptom onset varies, from several weeks after birth or later (asymptomatic into the 10s–20s).

Treatment Methods

• Medication treatment
  • In premature infants/newborns, prostaglandin synthesis inhibitors (indomethacin, ibuprofen) may be used to induce closure of the ductus arteriosus.
  • If closure is difficult with oxygen and medication, a procedure or surgery may be considered.
• Procedure (non-surgical)
  • A catheter-based cardiac procedure is used to insert a coil or closure device to block the ductus arteriosus.
  • General recommended conditions (provided information): The procedure is easier and has fewer complications when the patient weighs ≥ 10 kg and is approximately 2 years of age or older. The success rate is over 95%.
  • A small residual leak is common immediately after the procedure and often closes completely over time. If the residual leak persists, an additional device may be inserted.
• Surgery
  • If the ductus arteriosus is large and symptoms are present (such as heart failure), or if a procedure is not possible, immediate surgical ligation or division and ligation is performed.
  • In some low-weight newborns, division and ligation may be difficult, and simple ligation alone may be performed. Complete division (excision followed by suturing) is recommended for a large PDA.
• Follow-up and lifestyle management
  • After a procedure or surgery, regular echocardiography is used to check whether closure has occurred and to assess cardiac function.
  • Within 6 months after the procedure, antibiotics are recommended to prevent endocarditis for invasive dental procedures (e.g., tooth extraction, etc.) (not necessary after 6 months if complete closure has occurred). However, continued prophylaxis is recommended if a residual leak is present.
  • Activity restrictions are generally minimal (determined according to follow-up results after treatment).
• Precautions and risk of complications
  • Before and after treatment: Possible device embolization (dislodgement), vascular injury, bleeding, and cardiac rhythm abnormalities.
  • Long-term complications: If untreated, increased risk of pulmonary hypertension, right heart failure, and endocarditis.
  • Because the risks of surgery and procedures are higher in newborns and low-weight infants, consultation with a specialized center is required.

Checklist Before an Outpatient Visit (Items to Bring and Example Questions)

• Items to bring
  • A list of current medications (name, dose, and administration time)
  • Copies of previous test results (echocardiography, electrocardiography, chest X-rays, etc.) and surgical/procedure records
  • Growth records (changes in weight and height) and records of the frequency of symptoms such as shortness of breath, colds, and fever
  • Vaccination status (particularly during the newborn period and recent dental procedures)
• Items to organize for the outpatient visit (useful information to record in advance)
  • When symptoms first appeared and how they have changed
  • Whether shortness of breath or fatigue occurs during exercise, and symptoms during sleep
  • Frequent respiratory infections or history of hospitalization
• Materials to show the doctor during the outpatient visit
  • Recent echocardiography images and reports, medical certificates, and surgical/procedure reports

Examples of General Questions to Ask the Doctor

• "What is the most appropriate treatment for my condition (or my child's condition)—a procedure or surgery?"
• "What are the success rates and major complications of the procedure or surgery?"
• "What is the expected recovery period after treatment, and when can normal daily activities be resumed?"
• "Which tests should be used to monitor my condition after treatment, and how often should they be performed?"
• "Until when should antibiotics be taken to prevent endocarditis during dental treatment or other procedures?"

Examples of Disease-Specific Questions

• "Based on the size of the ductus arteriosus (or the echocardiography measurements), is closure by a procedure needed immediately? If it is safe to wait, according to what criteria will it be reassessed?"
• "My pulmonary artery pressure (or left ventricular load) is currently slightly elevated on echocardiography. How is the pulmonary artery pressure likely to change after the procedure, and what is the long-term prognosis?"