Echocardiography and MRI have completely ... the lateral view and pulmonary artery dilation: even significant ASD often has a normal cardiac silhouette and normal pulmonary vascularity.

Diagnosis is made on transthoracic echocardiography. The 12-lead ECG will show an incomplete right bundle branch block with right axis deviation (in contrast to the priumum ASD which has a left ...

A primum atrial septal defect is diagnosed on transthoracic echocardiography. The 12-lead ECG will show an incomplete right bundle branch block and left axis deviation (in contrast to the secundum ...