Cardiac output and stroke volume

Cardiac output (CO) is the volume of blood that heart pumps per minute, about 4-8 L/min at rest, and up to 30 L/min during exercise. Stroke volume (SV) is the volume of blood that is pumped with each heart beat, that is, cardiac output divided by heart rate (HR, heart beats per min):

Stroke volume is ∼85-105 mL, while the total volume of the filled left ventricular (LV) cavity (end diastolic volume, EDV) is about 120-140 mL. Thus about 35-55 mL blood remains in the LV (end systolic volume, ESV).

Ejection fraction (EF) is defined as

and EF is usually ∼0.6-0.7. Right ventricular (RV) volumes are similar than these LV volumes. The left ventricular and atrial volumes can be accurately and reproducibly assessed with MRI or CT (Järvinen et al., 2018).

Cardiac index (CI) relates CO to body surface area (BSA):

Verbraecken et al (2006) review the different formulas for calculating the BSA. CI at rest is normally 2.6-4.2 L/(min×m2). Maximal oxygen uptake (VO2max) is directly related to the CO and red blood cell mass.

Dynamic PET imaging studies of the heart can be used to estimate CO, providing that the bolus administration of radiopharmaceutical is sharp and very fine framing rate is achievable, so that the first-pass peak is separable from the recirculation of the radiopharmaceutical.

PET data analysis

From dynamic PET image data, the time-activity curve (TAC) from LV or RV cavity is extracted, avoiding the ventricular walls. Regions of interest in LV and RV cavities can be drawn manually or with semi-automatic clustering method (Chen et al., 1996; Wu et al., 2005; Harms et al., 2015). Then the first-pass peaks of the curves are isolated from the recirculation phase using exponential downslope fitting (Peters & Myers, 1998; Wu et al., 2005) or fitting gamma variate function to the portion of TAC prior to the time when the first recirculation arrived at the ROI of the ventricle (Chen et al., 1996). Cardiac output is calculated from Stewart-Hamilton indicator-dilution formula (Hamilton et al., 1948) as

, where blood curve CB(t) includes only the first-pass phase of the TAC (Chen et al., 1996; Sörensen et al., 2003; Knaapen et al., 2008). Forward stroke volume can then be calculated by dividing CO by heart rate (Eq. 1).

These methods have been used to estimate CO and/or SV in myocardial PET studies with [82Rb]Rb+ (Chen et al., 1996), [15O]H2O (Naum et al., 2007; Knaapen et al., 2008), and [1-11C]acetate (Harms et al., 2015).

Ejection fraction EF, and EDV and ESV have been assessed using gated PET imaging with [15O]CO (Boyd et al., 1996; Hofman et al., 2005), [15O]H2O (Nordström et al., 2017; Ben Bouallègue et al., 2018), [18F]FDG (Wang et al., 2013; Li et al., 2014; Saygin et al., 2017; Ben Bouallègue et al., 2021; Rasul et al., 2022), [1-11C]acetate (Harms et al., 2016), and [13N]NH4+ (Rasul et al., 2022; Maurer et al., 2023).

See also:


Ben Bouallègue F, Mariano-Goulart D, Agostini D, Manrique A. Feasibility of biventricular volume and function assessment using first-pass gated 15O-water PET. EJNMMI Res. 2018; 8(1): 92. doi: 10.1186/s13550-018-0445-x.

Chen EQ, MacIntyre WJ, Fouad FM, Brunken RC, Go RT, Wong CO, Saha GB, Dorosti K, Razavi M, Armstrong R. Measurement of cardiac output with first-pass determination during rubidium-82 PET myocardial perfusion imaging. Eur J Nucl Med. 1996; 23: 993–996. doi: 10.1007/bf01084378.

Fouad-Tarazi FM, MacIntyre WJ. Radionuclide methods for cardiac output determination. Eur Heart J. 1990; 11(Suppl I): 33-40. doi: 10.1093/eurheartj/11.suppl_i.33.

Hamilton WF, Riley RL, Attyah AM, Cournand A, Fowell DM, Himmelstein A, Noble RP, Remington JW, Richards Jr DW, Wheeler NC, Witham AC. Comparison of the Fick and dye injection methods of measuring the cardiac output in man. Am J Physiol. 1948; 153(2): 309-321. doi: 10.1152/ajplegacy.1948.153.2.309.

Harms HJ, Tolbod LP, Hansson NH, Kero T, Orndahl LH, Kim WY, Bjerner T, Bouchelouche K, Wiggers H, Frøkiær J, Sörensen J. Automatic extraction of forward stroke volume using dynamic PET/CT: a dual-tracer and dual-scanner validation in patients with heart valve disease. EJNMMI Phys. 2015; 2(1): 25. doi: 10.1186/s40658-015-0133-0.

Knaapen P, Lubberink M, Rijzewijk LJ, van der Meer RW, Unger M, Germans T, Bax JJ, Smit JWA, Lamb HJ, van Rossum AC, Diamant M, Visser FC, Lammertsma AA. Stroke volume measurements with first-pass dynamic positron emission tomography: comparison with cardiovascular magnetic resonance. J Nucl Cardiol. 2008; 15: 218–224. doi: 10.1016/j.nuclcard.2007.11.016.

Li Y, Wang L, Zhao SH, He ZX, Wang DY, Guo F, Fang W, Yang MF. Gated F-18 FDG PET for assessment of left ventricular volumes and ejection fraction using QGS and 4D-MSPECT in patients with heart failure: a comparison with cardiac MRI. PLoS One. 2014; 9(1): e80227. doi: 10.1371/journal.pone.0080227.

Nordström J, Kero T, Harms HJ, Widström C, Flachskampf FA, Sörensen J, Lubberink M. Calculation of left ventricular volumes and ejection fraction from dynamic cardiac-gated 15O-water PET/CT: 5D-PET. EJNMMI Phys. 2017; 4: 26. doi: 10.1186/s40658-017-0195-2.

Peters M, Myers MJ: Physiological Measurements With Radionuclides in Clinical Practice, 3rd ed., Oxford University Press, 1998. ISBN: 978-0192619945.

Verrecchia-Ramos E, Morel O, Retif P, Ben Mahmoud S. Innovative procedure for measuring left ventricular ejection fraction from 18F-FDG first-pass ultra-sensitive digital PET/CT images: evaluation with an anthropomorphic heart phantom. EJNMMI Phys. 2021; 8(1): 42. doi: 10.1186/s40658-021-00387-2.

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Updated at: 2023-05-04
Created at: 2023-01-13
Written by: Vesa Oikonen