The aims of the study is to investigate the right ventricular responses to mild hypercarbia after mitral valve prolapse repair surgery by the measurements obtained on pulmonary arterial catheter and transesophageal echocardiography.

The aims of the study is to investigate the right ventricular responses to mild hypercarbia after mitral valve prolapse repair surgery by the measurements obtained on pulmonary arterial catheter and transesophageal echocardiography. Investigators hypothesize that induced mild hypercarbia (PaCO2 7.5 kPa) cause elevated mean pulmonary arterial pressure and pulmonary vascular resistance, and this reflect to the right ventricle, both volume and function. And this right ventricle effect could be noticed by echocardiography.

Inclusion Criteria:

• scheduled mitral valve prolapse repair surgery
• able to give informed consent

Exclusion Criteria:

• preoperative right ventricular dysfunction or pulmonary hypertension
• significant tricuspid regurgitation
• congenital heart defect
• ventricular dyssynchrony or wide QRS-complex on ECG (> 130 ms)
• prior myocardial infarction (within tree months) or pericardial constriction
• preoperative left ventricular (LV) dysfunction, i.e. LV ejection fraction under 40 %
• if the scheduled repair by plastic procedure has been converted to mitral valve replacement