McConnell sign in Pulmonary Embolism: Mechanism
McConnell sign is hypokinesia of right ventricular free wall noted on echocardiography with sparing of the apex, seen in acute pulmonary embolism.1
Three mechanisms proposed for the McConnell sign are:
- Tethering of the right ventricular apex to the left ventricle which is hyperdynamic
- Abrupt increase in afterload causing the right ventricle to assume a more spherical shape to equalize regional wall stress
- Localized ischemia of right ventricular free wall due to elevated wall stress
- McConnell MV, Solomon SD, Rayan ME, Come PC, Goldhaber SZ, Lee RT. Regional right ventricular dysfunction detected by echocardiography in acute pulmonary embolism. Am J Cardiol. 1996; 78: 469-473.