From the Guidelines
The cardiac reservoir is not directly defined in the provided evidence, but based on the context, it can be inferred to refer to the left ventricular (LV) volume, with normal values for LV end-diastolic volume (EDV) being approximately 74 mL/m2 for men and 61 mL/m2 for women, as recommended by the American Society of Echocardiography and the European Association of Cardiovascular Imaging 1.
The concept of a cardiac reservoir in the context of cardiac function is crucial for understanding how the heart operates under different conditions. The left ventricle, being the main pumping chamber, has a specific volume that it can hold at the end of diastole (when the heart is fully relaxed and filled with blood), known as the end-diastolic volume (EDV). This volume is a critical determinant of cardiac performance because it influences the stroke volume (the amount of blood pumped out of the ventricle with each heartbeat) according to the Frank-Starling mechanism.
Key points about the cardiac reservoir, in this context, include:
- The normal values for LV EDV are 74 mL/m2 for men and 61 mL/m2 for women, as per the recommendations for cardiac chamber quantification by echocardiography in adults 1.
- These values are indexed to body surface area (BSA) to account for variations in body size among individuals.
- Maintaining these normal volumes is essential for optimal cardiac function. Deviations from these norms, either due to volume overload or underload conditions, can lead to ventricular remodeling and dysfunction.
- Echocardiography is a key diagnostic tool for assessing LV volumes and function, guiding clinical decisions regarding the management of cardiac conditions.
In clinical practice, understanding and measuring the cardiac reservoir (LV volume) is vital for diagnosing and managing various cardiac conditions, such as heart failure, valvular diseases, and cardiomyopathies. The provided evidence, particularly from 1, emphasizes the importance of accurate measurement and reporting of LV volumes using echocardiography, highlighting the biplane method of disks summation technique as the recommended approach for calculating volumes.
From the Research
Cardiac Reservoir and Normal Value
- The cardiac reservoir is not directly defined in the provided studies, but it can be related to the left atrial (LA) reservoir function, which is measured by strain 2.
- The normal upper limit of LA volume index (LAVi) is 24 mL/m2, and LA reservoir function does not differ among different age groups 2.
- There is no direct information on the normal value of the cardiac reservoir, but the normal cardiac index in healthy volunteers over 60 years of age is reported to be between 2.1 and 3.2 L/min/m2 3.
- The cardiac index is widely used as a parameter of cardiac function, and its normal value can vary depending on age and other factors 4, 3.
- The relationship between cardiac index and oxygen extraction can represent a useful basis for the interpretation of hemodynamic parameters in acutely ill patients 5.
- The accuracy of estimation of cardiac output by thermodilution versus the Fick method using measured oxygen uptake has been compared, and the results show a modest correlation between the two methods 6.