Figure 200g

Simultaneous base and apex phonocardiogram recorded together with the carotid pulse during with quiet respiration in a young woman with a large atrial septal defect. Wide, fixed splitting of S2 is present, and P2 is easily recorded at the apex. A prominent systolic ejection murmur (SEM) is recorded at the base and is due to the large stroke volume across the right ventricular outflow tract.