Atrial Septal Defect Type 2: What You Need to Know About Size and Treatment

Atrial Septal Defect (ASD) Type 2, also known as secundum ASD, refers to a hole in the atrial septum located within the fossa ovalis. This type of defect typically occurs due to incomplete development of the septum secundum or excessive absorption of the septum primum during fetal development. In some cases, if the base of the foramen ovale presents with a sieve-like structure, multiple small openings may be present.

Understanding the Size Range of Secundum ASD

The size of a secundum atrial septal defect can vary significantly, ranging from less than 3 millimeters to over 20 millimeters in diameter. This variation plays a crucial role in determining the potential for spontaneous closure and the likelihood of requiring medical intervention.

Prognosis and Spontaneous Closure

In younger patients, particularly children, smaller defects measuring less than 7-8mm in diameter may spontaneously close or decrease in size without medical intervention. However, larger defects are much less likely to close on their own and may lead to noticeable symptoms before the age of 40. Common symptoms include shortness of breath, fatigue, and heart palpitations.

Diagnosis and Treatment Options

Secundum ASD can be accurately diagnosed using transthoracic echocardiography, a non-invasive imaging technique that provides detailed views of the heart's structure. For defects that do not close spontaneously, especially those that are moderate to large in size, early surgical intervention or catheter-based closure is often recommended to prevent long-term complications such as pulmonary hypertension or heart failure.