A Quantitative Analysis of Left Ventricular Filling Pressures in Patients with a Reduced Ejection Fraction, with or without Concomitant Left Bundle Branch Block

AIM: This study aimed to prove that a mathematical model can be used to quantify the relationship between the left ventricular filling pressure (LVFP) determined as the E/e' ratio and the pulmonary capillary wedge pressure (PCWP) assessed by right heart catheterization (RHC) in patients with reduced ejection fractions (EF), with or without a left bundle branch block (LBBB). We hypothesize that such an approach will be clinically beneficial, especially for patients in the so-called "gray area," for whom E/e' is not a reliable index for assessment of the LVFP. METHOD: We enrolled 64 patients in sinus rhythm and with a reduced EF, 31 of whom exhibited a LBBB on an ECG. The e' was obtained from the septal (e'(sept)) and lateral sites (e'(lat)) of the mitral annulus. The averaged e' (e'(aver)) was also calculated (e'(sept) + e'(lat)/2). RESULTS: Although we found a good correlation (r = 0.641; e'(lat)/0.641; e'(sept)/0.607; e'(aver)) between E/e' and the mean PCWP in patients without LBBB, regardless of the e' used, the equation only yielded significance (P = 0.03) when the e'(aver) was used (PCWP = 6.7 + E/e'(aver)). In patients with LBBB, we found a moderate correlation between the LVFP and the mean PCWP (r = 0.451; e'(lat)/r = 0.413; e'(sept)/r = 0.454; e'(aver)), although all of the used e' positions lacked significance (P = 0.065 e'(lat)/0.075 e'(sept)/0.082 e'(aver)). CONCLUSION: Our results suggest that in patients with reduced EF and without LBBB, it is possible to quantify the LVFP using an equation. These results are of great clinical benefit, especially for "gray area" patients.