Mitral L-wave: The Missed Piece of Puzzle on Evaluation of Left Ventricular Diastolic Function across Different Ejection Fraction Phenotypes

Background and Objectives: The relationship between mitral L-wave and other mitral inflow parameters and its characteristics has not been previously addressed in patients with different ejection fraction (EF) phenotypes without heart failure. Methods: We studied 112 patients with prominent L-Wave, for the E, A, e', a', L, and L' velocities; R-E, R-e', E-L and e'-L', Isovolumic relaxation, and E and L deceleration times; E/A, E/L, and E/e' ratios of the mitral inflow, left ventricular (LV) EF%, and left atrial volume index (LAVI). Results: Group 1 (81%) had a preserved EF (≥50%). Group 2 had a greater LAVI (40 ± 17.4 mL/m 2 ), longer L-wave deceleration time (LDT) (230 ± 101 ms), and R-E (450 ± 65 ms), P < 0.05. L-Wave velocity had a positive correlation with E-wave velocity and negative correlations with E-L and corrected E to L time in all groups. For reduced EF, LDT was positively correlated with LAVI ( r = 0.6, P = 0.04). In preserved EF, L-wave velocity was negatively correlated with LDT ( r = −0.4, P = 0.01), R-R ( r = −0.3, P = 0.007), and R-E ( r = −5, P < 0.001); the LDT had positive correlations with the E-L ( r = 0.4, P = 0.005). Conclusion: Mitral L-wave could be a relevant parameter for evaluating LV diastolic function and filling pressure, especially when associated with a shorter E-L time. The trend in LDT differs between types of EF; it is longer with larger LAVI in reduced EF, but tends to be shorter with preserved EF because the mechanism of maintenance differs. A pathological L-wave appeared at a faster HR.