The ability of the global end-diastolic volume index (GEDVI), stroke volume variation (SVV) and pulse pressure variation (PPV) for prediction of fluid responsiveness in presence of left ventricular diastolic dysfunction is still unknown. The aim of the present study was to challenge the predictive power of GEDVI, SVV and PPV in cardiac surgery patients undergoing aortic valve replacement.

All patients receive premedication with midazolam 7.5 mg p.o.. After induction of anesthesia with sufentanil (0.5 µg/kg) and propofol (1.5 mg/kg), orotracheal intubation is facilitated with rocuronium (0.6 mg/kg). Anesthesia is maintained with sufentanil (1 µg/kg/h) and propofol (3 mg/kg/h) and patients are ventilated with an oxygen/air mixture in volume-controlled mode, using a tidal volume of 8 ml/kg related to the ideal body weight. Positive end-expiratory pressure is set at 5 cmH2O. Continuous monitoring is performed including electrocardiogram, radial arterial pressure catheter and a central venous catheter in the right or left internal jugular vein. Before placement of a transpulmonary thermodilution catheter a transesophageal echocardiography (TOE) is performed. TOE is used to detect diastolic dysfunction of the left ventricle and to exclude right ventricular dysfunction. In presence of left ventricular dysfunction a transpulmonary thermodilution catheter is placed in the femoral artery and connected to a PiCCO2 monitor (PiCCO2, Pulsion Medical Systems, Munich, Germany). Additionally capnography, urine output, temperature (blood, bladder and nasopharyngeal), airway pressure, and pulse oximetry are recorded.

Before starting operation a passive leg raising is performed. The passive leg raising maneuver (PLR) involves a leg elevation up to 45° with the trunk in a horizontal position and was performed to induce hemodynamic effects by a volume challenge, turning unstressed blood volume to stressed volume proportional to body size. In case of an increase of stroke volume index (SVI) >15% during PLR, patients were defined as responders.

All patients were studied with no changes in anesthesia management. Measurements of SVI, GEDVI, SVV and PPV are performed before, during and after PLR. Thereafter, patients receive a fluid Bolus of 500 ml crystalloids. Again, measurements are performed before and after fluid replacement.

Inclusion Criteria:

• Patients > 18 yrs of age
• Patients with a left ventricular ejection fraction ≥0.5
• Patients with left ventricular diastolic dysfunction.

Exclusion Criteria:

• Emergency procedures
• Right ventricular dysfunction
• Hemodynamic instability requiring pharmacologic Support
• Ongoing arrhythmia
• Intracardiac Shunts
• Severe mitral stenosis or insufficiency
• Aortic aneurysm > 4 cm
• Use of an artificial left ventricular assist device or intra - aortic balloon pump.