Diagnosis and Management of Adult Congenital Heart Defects

Epidemiological Evidence

The American Heart Association suggests that atrial septal defects (ASD) are more likely than patent ductus arteriosus (PDA) in adults with a heart murmur and normal vital signs, as ASD is one of the most common congenital heart defects diagnosed in adults, often incidentally in the second or third decade of life 1, 2
Approximately 57% of adults with ASD survive to adulthood without closure, and small defects (less than 10mm) may remain asymptomatic until the fourth or fifth decade of life 1, 2
The American College of Cardiology recommends that adults with ASD should be evaluated for closure, regardless of symptoms, if there is evidence of right ventricular volume overload 3, 4

The characteristic physical examination findings of ASD include fixed splitting of the second heart sound, systolic ejection murmur in the pulmonary area, and diastolic rumble due to increased flow across the tricuspid valve 2, 3, 4
In contrast, PDA typically presents with a continuous murmur ("machinery" murmur) best heard at the left infraclavicular area, and may also have a wide pulse pressure and bounding pulse 5, 6

The initial evaluation should include a thorough physical examination to confirm the presence of a heart murmur, followed by electrocardiography (ECG) and chest X-ray to assess for signs of right ventricular enlargement and pulmonary overcirculation 2, 3
Echocardiography is the gold standard for diagnosis, and can visualize the defect, demonstrate shunting, and assess right ventricular volume overload 2, 3
The American Society of Echocardiography recommends that transthoracic echocardiography be performed to confirm the diagnosis of ASD or PDA, and to assess the size and location of the defect, as well as the presence of any associated anomalies 2, 3

The American College of Cardiology recommends that adults with ASD should undergo closure, regardless of symptoms, if there is evidence of right ventricular volume overload, and that percutaneous closure is the preferred method for defects that are suitable for device closure 3, 4
The management of PDA typically involves surgical closure, although percutaneous closure may be possible in some cases, and the decision to close the defect should be made on a case-by-case basis, taking into account the size of the defect, the presence of symptoms, and the risk of complications 5, 6

The American Heart Association recommends the use of cardiac MRI to quantify the size and direction of the shunt and to clarify the anatomical structure, as stated by the Circulation guideline 7
The European Society of Cardiology notes that in patients with PDA, the development of Eisenmenger syndrome can lead to the disappearance of the continuous murmur and the appearance of differential cyanosis, as reported in the European Heart Journal 8

Cardiac MRI is used to evaluate the size and direction of the shunt and to assess the anatomical structure, with a strength of evidence based on the Circulation guideline 7