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Updated: Jun 17, 2026

Quadruple-Checkerboard: A Modification of the Three-Dimensional Checkerboard for Studying Drug Combinations
Published on: July 24, 2021
Don't stop at two
John A Purvis1, Vincent Kennedy, Albert J McNeill
1Cardiac Unit, Altnagelvin Hospital, Western HSC Trust, Glenshane Road, Londonderry, BT47 6SB, UK. john.purvis@btinternet.com
Abstract:
An asymptomatic 35-year-old woman with history of coarctation repair underwent routine echo. This showed a bicuspid aortic valve with a significant gradient in the left ventricular outflow tract (LVOT). The anterior mitral valve leaflet appeared redundant. Transoesophageal echo showed thickened chordae tendineae from both mitral valve leaflets inserted into a single postero-medial papillary muscle-a parachute mitral valve. During systole, there was anterior motion of redundant mitral chordae into the LVOT producing significant obstruction. A diagnosis of partial Shone complex was made. She was referred for mitral (and possibly aortic) valve surgery. The combination of aortic coarctation with bicuspid aortic valve should stimulate a search for other levels of systemic obstruction-don't stop at two!
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