To evaluate and to validate accuracy, precision and trending ability of blood pressure and cardiac output measurement by applanation tonometry in cardiological patients having:

• atrial fibrillation
• severe impaired leftventricular function
• severe aortic valve stenosis
• patients having left ventricular assist device

Experimental measurement: continuous blood pressure measurement and cardiac output measurement is performed by the T-Line 200 pro device (Tensys Medical Inc., San Diego, USA) Control measurement: gold-standard continuous blood pressure measurement is performed by invasive blood pressure measurement by arterial cannulation and cardiac output reference is assessed by transcardiopulmonary thermodilution

Increasing complexity of medical interventions and critical care treatment in an elderly getting population requires precise and accurate hemodynamic monitoring.(1) However, advanced invasive hemodynamic monitoring is often combined with complications by arterial or central venous catheterization. Complications such as vessel harming, infection, cardiac arrhythmias and nervous lesions are likely to occur.(2-4) Therefore, in the past various techniques of minimal- or non-invasive hemodynamic monitoring devices have been evaluated.(5, 6) One of the very promising technique is continuous non-invasive blood pressure monitoring by applanation tonometry. Published data revealed efficacy of this technique. (7) However, ability of this technique remains unclear in patients suffering from cardiological pathologies leading to changing stroke volumes as in arterial fibrillation, to highly reduces stroke volume as in severe impaired left-ventricular function or in severe aortic valve stenosis. Further, ability of applanation tonometry in patients without having pulsatile blood flow such as in patients with left-ventricular assist device remains unclear. Therefore, validation of this technique should be performed in the presented study.

Further development of applanation tonometry including pulse contour analysis now enables assessment of cardiac output. However, till now there is limited data assessing validation cardiac output measurement by this method. Cardiac output validation should also be performed in the planed clinical study.

Inclusion Criteria:

• atrial fibrillation
• severe impaired leftventricular function
• severe aortic stenosis
• LVAD Patients

Exclusion Criteria:

• Age <18 years
• pregnancy
• patients having blood pressure difference of more than 10 mmHg on both arms (measurement by "Riva-Rocci" before study enrolment)
• pre-existing on arterial vessels of the arms
• patients who are not able to give informed consent

Patients enable for study enrollement need to suffer from one of the four cardiological pathologies:

1. atrial fibrillation,
2. severe impaired leftventricular function,
3. severe aortic valve stenosis
4. patients having left ventricular assist device

All patients have to be clinically monitored by invasive blood pressure assessment and transcardiopulmonary thermodilution.