Evaluation of Cardiac Hemodynamic Modifications During Temporary Left Atrial Appendage Occlusion

All patients will undergo a standard surgical procedure by the surgical team of CHU Brugmann. A transesophageal echocardiogram (TEE) will be performed and the TEE probe will stay continuously during the entire procedure, to allow all necessary measurements.

All patients will undergo a standard surgical procedure by the surgical team of CHU Brugmann.During the procedure, a thermistor-tipped catheter (model 93A-131-7F, Edwards, Santa Ana, CA) will be inserted into the pulmonary artery to measure right atrial pressure (Pra), pulmonary arterial pressure (Ppa), Ppao and thermodilution cardiac output. Ringer's lactate will be infused to maintain an occluded pulmonary arterial pressure (Ppao) of 8-10 mmHg.

All patients will undergo a standard surgical procedure by the surgical team of CHU Brugmann.During the procedure, a pressure/volume catheter (CD Leicom, Zoetermeer, Netherland) will be placed in the left ventricle through a left superior pulmonary vein purse string, in order to measure alternatively LV pressure/volume loops and LA pressure.

"A complete transthoracic echocardiography will be performed the day before the surgical procedure. It will establish the presence of the inclusion and exclusion criteria, as stipulated above. This will be done using a Philips IE33 echocardiograph (Koninklijke Philips Electronics N.V., Netherlands).~During the surgical procedure, a transesophageal echocardiogram will be performed, using an Acuson Sequoia system (Siemens AG, Germany)."