Classic and Novel Echocardiographic Signs: A Review

Echocardiography is an important imaging modality in the assessment of cardiovascular diseases. Several echocardiographic signs have been described to aid in the diagnosis of specific clinical conditions and to help clinicians remember the key sonographic features. This review summarizes five classic signs in echocardiography, including the McConnell's Sign, the D-Sign, the 60:60 Sign, the SAM Sign, and the Swinging Heart Sign, as well as three novel signs, the Three Pipes Sign, the LTS Sign, and the LTI Sign. This review aims to provide an overview of the classic echocardiographic signs, focusing on their naming logics, definitions, and clinical implications to facilitate a better understanding of them, and to first propose three novel signs, the Three Pipes Sign, the LTS Sign, and the LTI Sign, which may aid in diagnosis and serve as teaching aids in echocardiography.