A TRIAL SEPTAL DEFECT (ASD)

Summary Intracardiac recordings in patients with primum‐ and secundum‐type atrial septal defects display no definite differences, except when the primum defect is associated with some lesion in the atrioventricular valves which produces a murmur. The intensity of the pulmonary component of the second sound grows with the pressure in the pulmonary artery. Murmurs are louder in patients with relative pulmonary stenosis than in other cases. No definite conclusions concerning the severity of the defect can he drawn from the intensity of the systolic murmur or the occurrence of a diastolic murmur. The murmur recorded most intensely in the second left intercostal space on the chest has its origin in the pulmonary artery. A case of atrioventricularis communis may be distinguished from a primum‐type defect by the holosystolic murmur heard in the ventricle of a patient with this condition. Intracardiac phonocardiography is not of clinical value for patients with atrial septal defects, except to confirm or exclude an additional lesion (e.g. ventricular septal defect).