1/ The intraventricular vortex fills the ventricle, and the downwards flow in the septal part, will close the anterior MV leaflet. This also isolates the vortex in the ventricle, which may conserve the kinetic energy in the vortex
2/ At the end of diastasis, the lateral part of the vortex, with apical flow, is aligned with the incoming inflow in atrial systole, adding momentum and kinetic energy to the inflow during atrial systole.
3/At the start of late inflow, simultaneous with mitral re opening, there is onset of a new phase of basal AV-plane motion.
4/ The basal motion of the AV-plane again will expand the LVOT, diverting blood towards the septum and downwards, creating a new vortex similarly to the early filling, which also originates near the ventricular base.
5/ This again creates into the LVOT, immediately before ejection. Earlier described as the “J-wave” pubmed.ncbi.nlm.nih.gov/2372400/, though incorrectly taken as return of the E-wave via apex, it was correctly, but inconsistently related the peak of the signal as related to the A-wave.
6/ It was later ascribed to early return of the A-wave, with a transit time of 20 - 80 ms, compared to 80 - 200 ms for the E_LVOT. pubmed.ncbi.nlm.nih.gov/8160627/ Although not evaluated in our study, it seems to be reasonable that the E_LVOT/A_LVOT ratio is related to the E/A ratio.
7a/ In a recent publication the A_LVOT was described as “pre systolic flow”, , reported in only a fraction of patents, irrespective of EF, but presence associated with worse prognosis. pubmed.ncbi.nlm.nih.gov/25440501/
7b As the amplitude of the A_LVOT is associated with the E/A ratio, low detection of A_LVOT may be related to the amplitude, creating a bias in detection towards a high E/A ratio, and thus being a confounder
8/ While the septal part of the early vortex seems to weaken, inflow in the A wave aligns with the lateral part, as the same time as the new vortex expands towards the apex.
9/ At the end of late filling, electromechanical activation creates a short duration apical motion before MVC, as published pubmed.ncbi.nlm.nih.gov/34184410/ and tweeted earlier
10/ At the same time, the vortex from the late inflow has a basal flow along the septum, directed towards the anterior mitral leaflet, that also may assist in MVC, as suggested previously.
1/ During pre ejection, the vortex is seen to persist after MVC, and the septal part aligns with left ventricular outflow. This adds momentum and kinetic energy to the ejection flow.
2/ During ejection, however, the vortex seems to disappear, outflow more or less filling the whole apex, as flow in the lateral part is recruited by the rapid flow into the LVOT.
🧵In our paper Intraventricular Vector Flow Imaging with Blood Speckle Tracking in Adults: Feasibility, Normal Physiology and Mech… we use a new method, not only BST, and can be applied on adult probes. pubmed.ncbi.nlm.nih.gov/34620522/
The main aim was to investigate the normal adult, intraventricular blood flow throughout the whole cardiac cycle, to compare with pw and colour Doppler M-mode and wall mechanics. (2D images courtesy of AS Daae).
As tweeted before, during IVR, there is simultaneous shortening of the base and elongation of the apex, inducing a volume shift with intraventricular apical flow, imparting a momentum and kinetic energy towards apex before start of early filling. This is thus *not* "wasted work"
Apart from the physiological implications, what are the consequences of this study onlinelibrary.wiley.com/doi/epdf/10.11… for timing of valve openings and closures by tissue Doppler?
1/ Valve closures can be timed by tissue Doppler and mitral ring motion. However, only the septal motion will reliably show AVC.
2/ MVO is close to the END of the pre ejection spike. Timing MVC by the start of the pre ejection spike will result in an error of about 40 ms too early. Timing by the peak R wave will result in about the same error.
The negative velocity post ejection spike had an average duration of 35 ms, ending about 10 ms after AVC in the septum. Thus, this spike is not isovolumic relaxation, and the true IVR (AVC to MVO) is from the end of the spike to start of mitral flow.
2/ 22 healthy subjects, Valve openings and closures timed by Doppler flow, and transewfrred to Tissue Doppler recordings.
3/ Pre ejection velocities started 24.8 ms after start QRS, with a duration of 51.5 ms, ending about 11.5 ms after MVC. Thus, both electromechanical delay and pre ejection velocity occurs *before* onset of IVC, and are not a measure of IVC or Isovolumic acceleration.