We sought to examine the relationship of the mitral L wave with echocardiographic indexes of diastolic function and heart failure (HF) events in patients with left ventricular (LV) hypertrophy (LVH).

The L wave, representing middiastolic transmitral flow, is of unknown clinical and prognostic significance in patients with LVH.

Consecutive echocardiograms performed during a 6-month period were screened for patients with LVH, normal LV ejection fraction, in sinus rhythm, and no significant valvular disease. Clinical and echocardiographic characteristics were analyzed, and patients were followed up for incident HF.

Of 177 patients, the L wave was present in 35 (20%) (group I) and absent in 142 (group II). Patients in group I had higher early (E) to late (A) transmitral flow velocity (E/A) ratio (1.2 vs 0.8), shorter mitral E wave deceleration time (201 vs 225 milliseconds), lower pulmonary venous systolic/diastolic velocity ratio (1.1 vs 1.6), shorter LV isovolumic relaxation time (83 vs 94 milliseconds), larger left atrial volume (36 vs 23 mL/m²), and higher E to early mitral annular velocity (E/E’) ratio (septal E/E’, 12.2 vs 9.1; lateral annular E/E’, 10.9 vs 7.8) compared with group II (all P < .05). The difference between pulmonary venous atrial reversal and mitral A wave durations was ≥ 30 milliseconds in more patients of group I (70% vs 6%, P < .001). During a mean follow-up of 12.0 months, 11 patients were hospitalized for HF. The L wave was associated with a hazard ratio of 4.7 (P = .011) for incident HF, and remained a significant predictor (hazard ratio 4.2, P = .026) after adjustment for cardiovascular risk factors.

In patients with LVH, the mitral L wave appears to be a marker of pseudonormal LV filling and predictor of future HF events.