incomplete closure in a sentence

Examples

1. Regurgitation in or near the heart is often caused by valvular insufficiency ( insufficient function, with incomplete closure, of the heart valves ); for example, aortic valve insufficiency causes regurgitation through that valve, called aortic regurgitation, and the terms " aortic insufficiency " and " aortic regurgitation " are so closely linked as usually to be treated as metonymically interchangeable.