Patients received a MitraClip procedure because of a leakiness of their mitral valves. During this procedure the atrioventricular valves were stuck together permanently via a clip which leads to a reduction of leakiness. As a result of this procedure a small hole remains at the cardiac septum which is called an atrial septal defect (ASD). In most cases the hole will close after a few weeks or months, but in many other cases not. Until now there is no exact data about the effect of this hole on the filling pressure in the heart or on the blood flow behaviour. So the aim of this study is a precise analysis of the blood flow mechanics during and after the MitraClip procedure to identify criteria to get more informations for a better strategy and regulation of the MitraClip procedure.

The percutaneous mitral valve reconstruction (PMVR) using the MitraClip system has become an established therapeutic alternative for patients with symptomatic mitral regurgitation and high operative risk. The MitraClip technology represent a catheter-based non-surgical procedure in which a metal cramp (clip) is transported to the place of the defective mitral valve. At the same time, it occurs also a 3-dimensional transesophageal echocardiogram (3D-TEE) with a transseptal puncture to control this procedure. After removal of the guiding catheter a new atrial septal defect can develop which can close spontaneously after weeks or months.

In this study criteria for a standardized evaluation about the effect of the new ASD on hemodynamic parameters - before and after the MitraClip procedure - shall be validated for the first time. The investigators expect to obtain new findings through the exact analysis of the newly formed ASD for the planning, regulation and follow-up of the mitral insufficiency treatment.

Inclusion Criteria:

• patients in which a percutaneous mitral valve reconstruction via the MitraClip system shall be performed due to severe mitral insufficiency because a conventional surgery would be too stressful for them
• legal age (≥18 years)
• written informed consent prior to study participation
• subjects who are contractually capable and mentally able to understand and follow the instructions of the study personnel

Exclusion Criteria:

• malignant diseases
• varicose veins of the esophagus
• patients with central nervous system dysfunction
• pregnant and lactating females
• subject has been committed to an institution by legal or regulatory order
• dependency or working relationship with the investigator
• participation in a parallel interventional clinical study