Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Acyanotic heart defect:

This text is part of the article's lead section, so referencing it may be optional. Please see WP:CITELEAD for more information.

"

An acyanotic heart defect, is a class of congenital heart defects. In these, blood is shunted (flows) from the left side of the heart to the right side of the heart, most often due to a structural defect (hole) in the interventricular septum.[1] People often retain normal levels of oxyhemoglobin saturation in systemic circulation.[citation needed]