Assessment of left ventricular function is an essential determinant of overall hemodynamics and heart function and therefore of central interest in intra-operative transesophageal echocardiography.

Currently, the most frequently used methods for quantification of left ventricular function are fractional shortening (FS) and fractional area change (FAC).

Radial strain is a new parameter to asses left ventricular function. The investigators want to assess left ventricular function with radial strain, fractional shortening (FS) and fractional area change (FAC) in non-cardiac patients during non-cardiac operations. The aim of this study is to show that radial strain is as reliable as FS and FAC in left ventricular function assessment and more robust to changes in preload and afterload conditions.

Assessment of left ventricular function is an essential determinant of overall hemodynamics and heart function and therefore of central interest in intra-operative transesophageal echocardiography.

Currently, the most frequently used methods for quantification of left ventricular function are fractional shortening (FS) and fractional area change (FAC). These parameters can be assessed in the transgastric mid papillary short axis view (TG SAX) to quantify left ventricular systolic function. Limitations of these methods are the experience of the investigator - the more experienced the investigator the more reliable and reproducible the data are, load dependency of these methods and the geometrical assumption of a one-dimensional measurement for assessment of a three-dimensional contracting left ventricle. Therefore, LV-function will either be over- or underestimated by influence of segmental wall motion abnormalities or by missing them.

Radial strain allows reliable and reproducible evaluation of left ventricular function and also allows assessment of myocardial deformation from representative segments of each wall of the left ventricle. Myocardial strain is described as the relative deformation of a myocardial fiber, normalized to its original length:L1-L0/L0(%). Strain is positive (radial thickening) if L1>L0 and negative (longitudinal shortening and circumferential thinning) if L1\

Inclusion Criteria:

• Planned non-cardiac surgery with a minimum duration of 60 minutes, where intubation is indicated
• Age above 18 years
• Signed informed consent

Exclusion Criteria:

• No patient's consent
• Subjects not able to understand study procedures
• Contraindications to transesophageal echocardiography (oesophageal-, gastric disorders, hematologic disorders with increased bleeding incidence, ENT-surgery, surgery of the oesophagus or stomach)
• Medical history of any kind of heart disease, dyspnea or angina pectoris
• Hypertension (medically treated)
• Diabetes
• Atrial fibrillation