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Rao. Vessel Plus 2022;6:24 https://dx.doi.org/10.20517/2574-1209.2021.91 Page 15 of 23

Table 4. Left ventricular function parameters examined
Parameter Derivation method
Systolic time intervals
Pre-ejection period (PEP) Onset of QRS to the opening of the aortic valve
Left ventricular ejection time (LVET) Opening to the closure of the aortic valve
Isovolumic contraction time (ICT) PEP - QMc
PEP/LVET ratio Ratio of PEP to LVET
Left ventricular volumes
LV end-diastolic volume (LVEDV) LVLDV = 1.05 × LVEDD3
LV end-systolic volume (LVESV) LVLSV = 1.05 × LVESD3
Stroke volume (SV) SV = LVEDV - LVESV
Ejection fraction (EF) EF = SV/LVEDV
Cardiac output (COP) COP = SV × heart rate
Shortening fraction SF = [(LVEDD - LVESD)/LVEDD] × 100
Velocity of circumferential fiber Vcf = (LVEDD - LVESD)/(LVEDD × LVET)
shortening (Vcf)
Percent thickening of LV posterior wall [(LV posterior wall thickness in end-systole - LV posterior wall thickness in end-diastole)/LV posterior
wall thickness in end-diastole) × 100]

LV: Left ventricle; LVEDD: LV end-diastolic dimension; LVESD: LV end-systolic dimension; QMc: Q wave of the ECG to closure of the mitral valve.
[21]
Reproduced from Ref. .

Figure 20. Selected video frames from apical four-chamber location demonstrating the left ventricle in end-diastole (LVED) in (A) and
in end-systole (LVES) in (B). Left ventricle (LV) area shortening may be calculated utilizing Simpson’s rule. Area shortening of the LV in
this example is 52% (see insert in B). Standard values are 55% to 75% (see text for details). Reproduced from Ref. [19] .

SF = [(LVIDd - LVIDs)/LVIDd] × 100

LVIDd, left ventricular end-diastolic dimension; LVIDs, left ventricular end-systolic dimension; and SF,
shortening fraction.

The shortening fraction does not depend on the rate of the heart and of the age of the patient with a normal
value of 33 ± 5. However, it is load-dependent.

LV area shortening by 2D echo
Another method that is useful is LV area shortening with the use of Simpson’s rule. This technique is
particularly valuable in the neonate and premature infant . The LV area shortening is calculated by the
[25]
formula: