Mitral annulus distortion during beating heart surgery: a potential cause for hemodynamic disturbance—a three-dimensional echocardiography reconstruction study

Background. Positioning for access to the coronary arteries leads to hemodynamic instability during off-pump cardiac surgery. External changes have been well described, but a description of the intracardiac structures in humans has not been described. Methods. With multiplane intraoperative echocardiography, the mitral annulus at end diastole was reconstructed in the different positions and correlated with hemodynamic changes in the right heart and left atrium. Results. Significant distortion of the mitral annulus with enlargement of the left atrium and pulmonary veins was demonstrated, which correlated with high left atrial pressures. Conclusions. Mitral valve distortion can significantly contribute to hemodynamic instability during positioning for off-pump cardiac surgery.