Changes in Cardiac Deformation Following Physiologic Alterations and Inotropic Support.
Changes in Cardiac Deformation Following Physiologic Alterations and Inotropic Support.
The investigators want to compare the effects of two drugs, levosimendan and milrinone, on
 cardiac muscle, both in terms of contractility and relaxation. Half of the participants will
 be randomized to each drug. The effects will be measured through echocardiographic
 deformation analyses.

 Since deformation analyses could be dependent on different loading conditions of the heart, a
 second purpose of the study is to investigate the changes on deformation parameters after
 applied changes in preload and afterload, but also heart rate.
Aortic stenosis is associated with myocardial hypertrophy and diastolic dysfunction. In
 patients undergoing open aortic valve replacement surgery due to stenosis, the investigators
 want to compare the effect on myocardial relaxation between two commonly used drugs,
 levosimendan and milrinone, using catheter-based measurements in combination with
 echocardiographic evaluation.

 Standard anaesthesia and surgical care for these patients is performed. After surgery is
 completed and the participant is transferred to the intensive care unit, the studies are
 performed during general anaesthesia and the participants still connected to a respirator
 with controlled ventilation.

 Echocardiographic data will be collected simultaneously with hemodynamic parameters - first
 at two control measurements, then after each of two different doses of the drug. Preload,
 afterload and heart rate will be kept stable during this intervention. The echocardiographic
 data is later analyzed offline for strain and strain rate.

 To further investigate the dependency of strain and strain rate on changes in preload,
 afterload, and heart rate, these variables are consecutively changed prior to drug
 administration. For this purpose, all patients first have their baseline data recorded,
 thereafter are paced at two different rates, then preload and afterload is altered by passive
 leg elevation and phenylephrine, respectively. Hemodynamic and echocardiographic data are
 collected simultaneously at baseline and after each intervention. Before administration of
 the drugs, baseline conditions are restored.
Inclusion Criteria:

 -  Subject has aortic valve stenosis

 -  Subject is scheduled for open heart aortic valve replacement with or without
 simultaneous coronary artery bypass grafting

 Exclusion Criteria:

 -  Less than normal systolic function, defined as ejection fraction less than 0,5

 -  Non-sinus rhythm

 -  Any major surgical complication

 -  Problems understanding the informed consent