Previously published formulae derived from TTE:
Equation 1: PCWP = 31.7 ─ 0.134 X DT11
Equation 2: PCWP = 8.8 X E ⁄ Vp ─ 1.9 12
Equation 3: PCWP = 18.4 + (17.1 X E ⁄ A) 13
Equation 4: PCWP = 0.97 X E ⁄ Ea + 4.34 14
Equation 5: PCWP = 3.91 E ⁄ Vp + 4.92 14
Equation 6: PCWP = 35 ─ 0.39 SF (where % systolic fraction
is calculated using velocity time integrals rather than
peak velocities)15.
The following measurements were taken from transesophageal echocardiography:
1. Left ventricular inflow Doppler spectral display was obtained from the mid-oesophageal four-chamber view with the sample volume placed at the mitral valve tips. Measurements included peak early diastolic velocity, E ; late velocity, A(cm/sec); deceleration time of E-wave, DT and A wave duration(msec).
2. Pulmonary venous spectral Doppler was recorded with the sample volume placed 0.5–1 cm into the left pulmonary vein from the mid-esophageal four-chamber view. Measurements included peak velocities of the systolic S and diastolic D, atrial reversal AR velocities (cm/sec) and AR duration(m sec).
3. Left ventricular flow propagation velocity, Vp(cm/sec) was measured from the mid-esophageal four- chamber view as the first aliasing velocity during early mitral filling. Measurements were taken from the mitral valve leaflets to 4 cm distally into the left ventricle.
4. Tissue Doppler imaging was obtained from the mid-esophageal four-chamber view, with the cursor placed over the basal lateral wall at mitral annulus level. Measurements included early left ventricular filling, Ea(cm/sec).