Table 3. Calculations of heart function indicators.

MAP, mean aortic pressure; SAP, systolic aortic pressure; DAP, diastolic aortic pressure; LVEDS, left ventricular end-diastolic surface; LVESS, left ventricular end-systolic surface; LVESP, left ventricular end-systolic pressure; AOD, left ventricular outflow tract diameter; HR, heart rate; V₀, intersection of end-systolic pressure volume relationship with volume axis.

Stroke Volume	$SV=\pi \frac{{\text{AOD}}^2}{4}·\text{VTI}$
Left Ventricular End-Diastolic Volume	$\text{LVEDV}={\sum }_{i=1}^n\text{pixel}\text{spacing}·\pi \frac{{\text{LVEDS}}^2}{4}$
Left Ventricular End-Systolic Volume	$\text{LVESV}={\sum }_{i=1}^n\text{pixel}\text{spacing}·\pi \frac{{\text{LVESS}}^2}{4}$
Left Ventricular Ejection Fraction	$\text{LVEF}=\frac{\text{LVEDV}-\text{LVESV}}{\text{LVEDV}}$
Pulse Pressure	PP = SAP − DAP
Cardiac Output	CO = SV ⋅ HR
Total Arterial Compliance	${\mathrm{C}}_{tot}=\frac{\text{SV}}{\text{PP}}$
Systemic Vascular Resistance	$\text{SVR}=\frac{\text{MAP}}{\text{CO}}$
Arterial Elastance	${\mathrm{E}}_a=\frac{\text{LVESP}}{\text{SV}}$
Ventricular Elastance	${\mathrm{E}}_{es}=\frac{{\text{LVESP}}_{highPreload}-{\text{LVESP}}_{lowPreload}}{{\text{LVESV}}_{highPreload}-{\text{LVESV}}_{lowPreload}}$
Ventricular-Arterial Coupling	${\mathrm{V}}_{va}=\frac{{\mathrm{E}}_a}{{\mathrm{E}}_{es}}$
Internal Work	${\mathrm{I}}_w=\frac{\text{LVESP}(\text{LVEDV}-{\mathrm{V}}_0)}{2}$
External Work	Ew = area under PV loop
Cardiac Efficiency	$\text{CE}=\frac{{\mathrm{E}}_w}{{\mathrm{E}}_w+{\mathrm{I}}_w}$