Welcome to the emerging revised strain rate website
The strain rate website has become fairly
tangled in the process of editing single paragraphs at a time.
Thus, I will attempt to revise the text for better legibility. I
will keep the formats of sections, for quicker uploading, but
get rid of duplications as well as reducing the number of
sections. The index portal will be simplified, and just contain
the index to the sections without text, and few pictures.
Animations will still be in *.GIF format, so they will run on
web browsers, and can be embedded in presentations. Pictures and
animations are still free to use, with due credit.
Strain and strain rate are the concepts of myocardial
deformation. My basic views are still that
- Any imaging method deals with myocyte shortening, myocyte
shortening is always a function of tension versus load, and
thus any
imaging method and measure is load dependent,
including deformation and deformation derived measures.
- The three
strain components are only coordinates of the total
three dimensional deformation of one object - the
myocardium, and thus interdependent, but also meaning that
longitudinal strain carries most of the information
- Longitudinal
strain is method dependent, so there is no gold
standard
- Gradient
of longitudinal layer strain, is just an artefact of
speckle tracking, tracking the inward motion, which
increases towards the endocardium.
- Gradient
of circumferential and transmural strain are just a
function of inward expansion into a progressively smaller
space toward the center of the left ventricle, i.e.
geometry, not differential layer function.
- For global function, annular
motion (displacement and velocity are basically as useful
as global strain and strain rate,
- Except in the right ventricle where
deformation is superior,
- But when there is regional dysfunction, annular motion is
not enough, deformation is necessary, but as an
adjunct method, and here, peak values are less useful,
qualitative and semi-qualitative information is more
important: curve shapes or colour M-mode, the typical acute
ischemic segmental pattern is:
- Delayed onset of shortening
- Reduced rate and amount of shortening
- post systolic shortening
Recent additions:
November 10th. Global longitudinal strain is the
most commonly used deformation measure of LV global function.
The definition gives the GLS as negative values, and more
negative values means more contraction. Should GLS be given in
signed or numerical values (numerical values of GLS are the
relative longitudinal shortening)? This
is discussed here.
Website index:
Basic concepts of motion and deformation
This section replaces the two old sections:
- Basic concepts of motion and deformation
- Basic concepts in myocardial strain and strain rate
Basic physiology
This section deals with the basic physiology as seen with
various echo methods, and replaces most of
- Basic physiological concepts in strain and strain rate -
What does strain and strain rate actually measure?
- Global systolic functional imaging
- Regional systolic functional imaging.
- Diastolic functional imaging
In the physiological aspects, as these were largely overlapping
anyway.
Basic ultrasound
This section is still under revision, and replaces the sections
on
Strain ultrasound
Problems and pitfalls
have been updated, especially in the order they are given.
Cardiotoots
I'll blog short #Cardiotoots related to #EchoFirst
paragraphs in the website here on the front page, as well
as on social media. Older toots will be collected in an archive file.
The newest #Cardiotoot: