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.