Haemodynamic normal values: reference values for precise cardiovascular diagnostics
Haemodynamic normal values form the basis for assessing cardiovascular function in modern cardiac catheterisation laboratories. These standardised reference values enable cardiologists to identify pathological changes and make therapeutic decisions. The recording and evaluation of intracardiac and intravascular pressure values are an essential part of every cardiac catheter examination, with precise haemodynamic reference values serving as a guide for clinical assessment.
Basics of haemodynamic reference values
Haemodynamics describes the flow of blood in the blood vessels depending on the forces responsible. However, haemodynamic reference values are not uniformly defined, which is why the literature sometimes contains widely differing figures.
Haemodynamic target values must always be determined individually depending on the overall clinical situation. The progression is often more decisive than absolute values, as the parameters determined are subject to numerous influencing factors.
Cardiac output normal values
Cardiac output (CO) is the volume of blood ejected by the heart per minute, with normal values ranging from 4 to 8 litres per minute. The cardiac index is expressed in relation to body surface area and is normally 2.5 to 4 (litres/minute)/m².
The stroke volume in adult patients is between 40 and 80 ml per beat. Significantly lower values are normal in newborns, where the stroke volume is between 3 and 5 ml per beat.
Normal blood pressure values in cardiac catheterisation
The heart rate in adults is normally between 60 and 100 beats per minute. A normal blood pressure value is around 120/80 mmHg, whereby the systolic value should not exceed 120 mmHg and the diastolic value should not exceed 80 mmHg.
Mean arterial pressure (MAP) is an important parameter for assessing organ perfusion and is continuously monitored during haemodynamic measurements.
Pulmonary haemodynamics normal values
Pulmonary arterial pressure (PAP) has characteristic normal values: systolic 25 ± 7 mmHg, diastolic 9 ± 4 mmHg, mean pressure 15 ± 5 mmHg. These values are essential for the diagnosis of pulmonary hypertension.
Pulmonary artery occlusion pressure (PAOP) corresponds approximately to left atrial and left ventricular end-diastolic pressure. An increase in PAOP > 25 mmHg confirms the diagnosis of heart failure with corresponding symptoms.
Systemic vascular resistance (SVR)
The systemic vascular resistance index (SVRI) is normally between 1400 and 2500 dyn*s/cm5/m². This parameter reflects the afterload of the heart and describes the relationship between systemic pressure and blood flow.
The central venous pressure (CVP) has a normal range of 0–5 mmHg, whereby changes in values over time are more important than absolute values.
Volume parameters and fluid status
The Extravascular Lung Water Index (ELWI) has a normal value of 3–7 ml/kgBW and is used to assess pulmonary oedema. A stroke volume variation (SVV) of 9.5% indicates a 5% increase in stroke volume after a fluid infusion of 100 ml.
The pulse pressure variation (PPV) is normally below 13%, while the systolic blood pressure variation (SPV) should remain below 10%.
Oxygen transport and tissue oxygenation
Central or mixed venous oxygen saturation is a parameter for indirectly assessing tissue oxygenation. Normal values are 65-75% for central venous oxygen saturation and 70-75% for mixed venous oxygen saturation.
A drop in oxygen saturation is due to an increase in oxygen consumption or a decrease in oxygen supply.
Contractility parameters
The velocity index (VI) corresponds to the maximum velocity of blood flow in the aorta and serves as a contractility parameter. The acceleration index (ACI) describes the maximum acceleration of blood flow.
The pre-ejection period (PEP) represents the duration of the isovolumetric contraction of the ventricle during electrical systole.
Special features in paediatric patients
Different haemodynamic reference values apply to newborns. For example, the cardiac index (CI) is 2.4 L/min/m², which is appropriate for this age group. The cardiac output in newborns is approximately 0.37 L/min.
These significant differences between adult and paediatric patients highlight the need for age-adjusted reference values.
Clinical evaluation and interpretation
The findings of haemodynamic monitoring must always be evaluated in conjunction with the overall clinical picture. Haemodynamic target values must be determined individually, with the overall clinical situation being decisive.
To avoid serious complications, the cause of haemodynamic instability should be identified and corrected as quickly as possible.
Technical aspects
Correct zero point adjustment and the operating principle of the pressure transducer are essential for accurate measurements. All pressure values in the heart are clearly presented in tabular overviews.
This is followed by methods and formulas for calculating the most important parameters for diagnosis, such as determining cardiac output, pressure gradients and valve opening areas.
Modern measurement systems and standard values
Haemodynamic recording systems for measuring and calculating invasive blood pressure, cardiac output and all relevant vital parameters offer interfaces to all X-ray providers and compact amplifiers with excellent signal quality.
Systems such as the evolution from Schwarzer Cardiotek offer a smart keyboard that enables intuitive operation with haptic feedback, while automatic measurement algorithms support the precise determination of haemodynamic standard values.
Precise haemodynamic normal values for reliable diagnostics
Haemodynamic reference values are indispensable reference values for modern cardiovascular diagnostics and form the basis for well-founded therapeutic decisions. The continuous further development of measurement technology and the refinement of reference values contribute to improving patient care.
The correct interpretation of haemodynamic parameters in conjunction with established normal values enables cardiologists to detect pathological changes at an early stage and initiate targeted therapies. Modern measurement systems support this with automated calculations and precise data acquisition.
Note: This article is for informational purposes only and does not replace professional advice from qualified cardiologists. Haemodynamic normal values can vary from person to person and must always be evaluated in a clinical context.