Mid-Diastolic Events (L Events): A Critical Review

Figures

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  Figure 1. Mid-diastolic events. (a) Mid-diastolic mitral velocity at the level of lateral annulus (L’ wave). (b) Mid-diastolic transmitral flow (L wave). (c) Mid-diastolic mitral valve motion (L motion). Note the “W” shape of the anterior mitral leaflet motion. (d) Mid-diastolic transmitral flow and right upper pulmonary vein flow in color M-mode sampling. The white arrows indicate L events.

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  Figure 2. Color Doppler imaging for the analysis of the L wave and flow pathway. The upper panels (A–F) show the transmitral and right upper pulmonary vein flow sampled simultaneously in the color Doppler apical four-chamber view. The lower panel shows the corresponding transmitral flow sampled in pulsed-wave Doppler (a–f). (A) (a) Systolic phase: anterograde pulmonary vein flow and mitral valve closure. (B,C) Early diastolic phase: anterograde mitral and pulmonary vein flows, (b,c) E wave. (D) Diastasis: transmitral mid-diastolic flow and continuous pulmonary vein flow, (d) L wave. (E) End-diastolic phase: increased mitral flow velocity and no pulmonary vein flow, (e) A wave. (F) Early systolic phase: mitral valve closure.

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  Figure 3. Left atrial pressure–volume curve.

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  Figure 4. The upper and lower panels show septal mitral annular velocity by tissue Doppler imaging (TDI) and transmitral flow velocity in the pulsed-wave Doppler mode, respectively. The two Doppler spectra relate to two consecutive RR cycles which had the same duration of 1100 ms (dashed green lines), therefore a temporal comparison was possible.

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  Figure 5. Temporal relationships between velocity, strain rate ventricular curves, and transmitral flow patterns in pulsed-wave Doppler. The upper panel shows the strain rate (yellow) and velocity (blue) ventricular curves. The lower panel shows the spectral Doppler of transmitral flow. The E wave happens before the early diastolic peak velocity and strain rate of the left ventricle. The mid-diastolic events occur simultaneously. SR-E: peak early diastolic strain rate; SR-L: peak mid-diastolic strain rate; SR-A: peak late diastolic strain rate; G–E’: global early diastolic ventricular velocity using STI; G–L’: global mid-diastolic ventricular velocity using STI; G–A’: global late diastolic ventricular velocity using STI; E wave: early diastolic transmitral flow velocity; L wave: mid-diastolic transmitral flow velocity; A wave: late transmitral flow velocity.

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  Figure 6. Atrial and ventricular strain, strain rate, and velocity curves obtained from the four-chamber view of the same reference heartbeat. The red arrow indicates the global mid-diastolic ventricular velocity using STI (G–L’). The yellow arrow indicates the peak mid-diastolic strain rate (SR-L). The atrial stain, velocity, and strain rate curves do not show any significant changes in correspondence with mid-diastolic ventricular events.