Most infants with ASD have no symptoms, and the ASD goes undiagnosed. The ASD can be an incidental finding when an echocardiogram is performed for other reasons.
The most common presentation of an ASD is that of a cardiac murmur. The murmur caused by the ASD is generally soft, and there can also be associated changes in the normal heart sounds. Less commonly, babies with large ASD can present with symptoms of heart failure such as rapid breathing and poor feeding.
The chest X-ray and electrocardiogram are often non-specific; they can be totally normal in small ASDs. In larger defects, the chest X-ray can show enlargement of the heart and increased blood vessel markings in the lungs. The electrocardiogram can sometimes shows subtle changes that lead a doctor to suspect the presence of an ASD.
The investigation of choice when an ASD is suspected is the echocardiogram. This will not only confirm the presence of the ASD, it will also allow the cardiologist to assess the number and sizes of the ASD(s), as well as it's effects on the heart. The echocardiogram can also shows any other associated cardiac defects and well as the suitability of the various treatment options. Figure 2.4 is a still frame taken during an echocardiographic study and shows the presence of an ASD. Hover your pointer over the picture for labels, or click on the picture for a short movie clip of color flow mapping showing blood flowing across the ASD.
Figure 2.4 Echocardiogram showing the presence of an atrial septal defect. Hover pointer to see labels, click to see color flow study showing blood flowing across the defect.
