Marcus Schreckenberg

Mass-spring systems for simulating mitral valve repair using 3D ultrasound images

Mitral valve (MV) diseases are among the most common types of heart diseases, while heart diseases are the most common cause of death worldwide. MV repair surgery is connected to higher survival rates and fewer complications than the total replacement of the MV, but MV repair requires extensive patient-specific therapy planning. The simulation of MV repair with a patient-specific model could help to optimize surgery results and make MV repair available to more patients. However, current patient-specific simulations are difficult to transfer to clinical application because of time-constraints or prohibitive requirements on the resolution of the image data. As one possible solution to the problem of patient-specific MV modeling, we present a mass-spring MV model based on 3D transesophageal echocardiographic (TEE) images already routinely acquired for MV repair therapy planning. Our novel approach to the rest-length estimation of springs allows us to model the global support of the MV leaflets through the chordae tendinae without the need for high-resolution image data. The model is used to simulate MV annuloplasty for five patients undergoing MV repair, and the simulated results are compared to post-surgical TEE images. The comparison shows that our model is able to provide a qualitative estimate of annuloplasty surgery. In addition, the data suggests that the model might also be applied to simulating the implantation of artificial chordae.

Heart Failure With Recovered Ejection Fraction

Recently, the term heart failure (HF) with recovered ejection fraction (HFrecovEF) was introduced for patients with a normalization of the left ventricular ejection fraction (LVEF) [(1)][1]. The question remains whether this means true recovery of systolic left ventricular function or simply

3D-Vermessung der regionalen Wandverdickung des Herzmuskels in 3D-Echokardiographiesequenzen

Die Leistungsfahigkeit des linken Herzmuskels kann direkt aus der Verdickung der Herzwand wahrend der Kontraktionsphase ermittelt werden. Von besonderem Interesse ist dabei die lokale Verteilung der relativen Wandverdickung. Sie gibt Aufschlus uber dysfunktionale Bereiche des Herzmuskels, die z.B. nach Herzinfarkt oder bei Durchblutungsstorungen der Herzkranzgefase entstehen konnen. Bisherigen Ansatzen liegt eine Messung der Wandstarken in ebenen Schnitten durch den Ventrikel zugrunde. Dabei treten grose systematische Mesfehler auf, die nur zum Teil durch Korrekturfaktoren verkleinert werden konnen.