Reinterpreting Isovolumetric Relaxation: Decompression
Phase.
As a consequence of the shortening of the DS during ejection,
lengthening of the AS occurs, beginning its intervention in this phase
with its contraction, it shortening during the criticized phase of
isovolumetric relaxation30. At this moment the overall
result of its shortening causes a clockwise reversal after ejection
since it reverses its ejection-conditioned movement which is
counterclockwise, (Figure 2: 2A-B) as a result, the LV
elongates from the straightening of the AS just when the DS has stopped
contracting but maintains rigidity and tension33(Figure 4: 2A-C) together with the recently reported
osteochondroid tissue, the fulcrum or support point of the myocardium is
obtained17 for the AS straightening, base elevation as
it continues to contract unopposed for approximately 90 ms more. The AS
according to experimental studies begins to contract approximately 60 ms
later than the DS, followed by a time interval of 90 ms that marks the
difference between the end of the DS contraction, followed by the
shortening of the AS31, 32. (Figure 3:
Transition from color yellow to green)
With an apical 5-chamber echocardiographic window, during the closure of
the aortic valve a longitudinal elongation of the ventricles is
observed, as well as a subsequent widening of the cavities. This
simultaneous elevation and straightening are due to the shortening of
the AS, its activity as already mentioned, is delayed until the interval
of the isovolumic relaxation when its current contraction is not
accompanied by that of the DS, observed as a positive deflection of the
longitudinal strain of the AS (28) and a velocity
vector directed upwards (the base rises and separates from the
apex.)[7] (Figure 4: 2 A-C observe the change of
direction of the subepicardial vectors undertakes a direction towards
the base which is manifested at the end of the isovolumetric
relaxation.) also occurs the widening of both cavities without
flowometric exchange related to the retreat of the circumferential
muscle that has stopped contracting, particularly in the RV, different
characteristics have been experimentally reported, defining a phase of
longer ejection divided into early and late and the absence of a phase
of isovolumic relaxation34. This detorsion of the LV
generated by the contraction of the AS produces the elongation that
creates a negative pressure and a vacuum generating the suction of blood
during rapid filling35. (Figure 4: 2C)