What is the most appropriate variable for estimation of mean pulmonary capillary wedge pressure by transesophageal pulsed Doppler echocardiography?

Although left ventricular (LV) inflow and pulmonary venous (PV) flow variables estimated by transesophageal Doppler echocardiography (TEE) reflect pulmonary capillary wedge pressure (PCWP), they are also affected by changes in cardiac function. The purpose of the present study was to detect the most appropriate variable for the estimation of PCWP by TEE in patients (pts) with ischemic heart disease. Several variables of LV inflow and left upper PV flow were compared with PCWP in 36 pts (six with angina pectoris and 30 with old myocardial infarction). Early diastolic flow (E) and atrial contraction flow (A) were used as LV inflow, while systolic forward flow (X), diastolic forward flow (Y) and atrial contractile reversal flow (z) were used as PV flow. The peak velocity of each flow wave (Ep, Ap, Xp, Yp, and Zp) and the time-velocity integral (Ei, Ai, Xi, Yi, and Zi) were measured. The ratio of Ep to Ap (Ep/Ap), Ei to Ai (Ei/Ai), Xp to Yp (Xp/Yp), Xi to Yi (Xi/Yi), Zp to Ap (Zp/Ap), Zi to Ai (Zi/Ai) and the systolic fraction of PV forward flow were calculated. Among these variables, the Zi/Ai ratio was most strongly correlated with PCWP (R=0.80). The Zi/Ai ratio may not be influeced by atrial function because the augmentation of atrial pump function increases Zi as well as Ai, and this may be one reason why the ratio correlated well with PCWP.Conclusion: The Zi/Ai ratio is a new useful variable for estimating PCWP by TEE.Abbreviations Ap peak velocity of left ventricular inflow during atrial contraction - Ep peak velocity of left ventricular inflow during early diastole - Yp peak velocity of diastolic pulmonary venous forward flow - Xp peak velocity of systolic pulmonary venous forward flow - Zp peak velocity of pulmonary venous reversal flow during atrial contraction - Ai time-velocity integral of left ventricular inflow during atrial contraction - Ei timevelocity integral of left ventricular inflow during early diastole - Yi time-velocity integral of diastolic pulmonary venous forward flow - Zi time-velocity integral of pulmonary venous reversal flow during atrial contraction - Xi time-velocity integral of systolic pulmonary venous forward flow