Heart Sounds Research Lab
Arterial Septal Defect (ASD)
The Heart Sounds and Murmurs Laboratory | 6560 Fannin St, Suite 1836| Houston, Texas 77030 | 832-355-2937
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Delay of the pulmonary closure component of the second heart sound (S2) may occur with a multitude
of different alterations in right heart dynamics. When right ventricular emptying is delayed because of a
volume overload, such as that produced by an atrial septal defect (ASD), the aortic and pulmonary
components will be widely split and will vary little or not at all during respiration. Splitting of S2 may
persist in intervals of 0.03 to 0.06 second magnitude.
Wide, Fixed Split S2 (ASD)