Typical bedside findings of an atrial septal defect include equally prominent "a" and "v" waves, reflecting equal right and left atrial pressures; prominent pulmonary artery and right ventricular impulses, a systolic ejection murmur at the upper left sternal edge; wide, fixed splitting of the second heart sound; and a mid diastolic murmur at the lower left sternal edge. These findings are due to right ventricular volume overload.