GIAN LUIGI NICOLOSI,VITTORIO DALL’AGLIO, CHIARA LESTUZZI,RENATA MIMO,DANIELA PAVAN, DOMENICO ZANUTTINI
Cardiologia, Ospedale Civile, 33170 Pordenone, Italy
© 1990 Elsevier Science
Published B.V. (Biomedical Division)
Echocardiography 1990
A. Dagianti and H. Feigenbaum, editors Ischemic heart disease and several other cardiac disorders are associated with regional
abnormalities in ventricular structure and function.
Two-dimensional echocardiography, because of its characteristics of spatial and temporal resolution, is a real-time tomographic technique especially
suitable for regional analysis of left ventricular wall abnormalities, either structural and functional [1-6].
In current clinical practice, a semi quantitative method that derives wait motion score based on a visual impression of regional wall motion is
commonly utilized [1-6]. Several studies using a variety of segmental divisions and different methods of analysis of wall motion have been published
[1-6]. REPORTED METHODS The reported methods divide the base-apex length (long axis) of the left ventricle
into three nearly equally spaced thirds.These three levels are basal, mid and apical. The basal region lies between the reference line drawn through
the base of the heart and a line drawn through the tips of the left ventricular papillary muscles. The mid region lies between a line drawn through the
most caudal portion of the base of the papillary muscles and a line drawn through the tips of the papillary muscles. The apical region lies between a
line drawn through the tip of the cardiac apex and a line drawn through the most caudal portion of the base of the papillary muscles [1-6].
Using short-axis planes through the mid-portion of each of the three long-axis regions, the left ventricular free wall and the ventricular septum can
be further subdivided. The basal and the mid region can be subdivided into 5, 6 or 8 segments. The apical region can be considered as a single segment
or subdivided into 4 segments. These different classifications leads to an 11 segment model [3], a 14 segment model [1], a 16 segment model [5], a 20
segment model [4]. ADVANTAGES AND DISADVANTAGES OF THESE CLASSIFICATIONS Each of these classifications has
advantages and disadvantages. All these classification systems [1,3,4,5] are compatible with anatomic data which indicate that the ventricular septum
forms approximately 40% of the circumference of the left ventricle [1]. All allows easy identification of the segments using internal anatomic
landmarks [1,3,4,5].
The ventricular segments tend to correlate well with common patterns of coronary arterial distribution [1]. However, myocardial regions will almost
never correlate precisely with coronary blood flow,because the patterns of coronary distribution are so highly variable [1].Furthermore any given
myocardial region may, in some person, receive its blood supply from the branches of two independent major epicardial arteries [1].
Classification models which subdivide the left ventricle into an even number of myocardial segments around the short-axis [4,5] are such that every
myocardial wall segment has a complimentary myocardial segment exactly opposite (i.e.180 degrees) from it. This feature is particularly useful when
comparing myocardial wall segments identified with two-dimensional echocardiography to shadow-graphic images of the left ventricle such as those
obtained with contrast ventriculography, radionuclide cineangiography or thallium scintigraphy [4].
By subdividing the left ventricle into a larger number of segments around the short-axis, functional abnormalities can be described more clearly and
precisely. This leads to a better correlation with generally employed anatomic and electrocardiographic terms [4,5].
Classifications with lower number of segments tend to overestimate the percent age of dissynergic areas. Classifications with higher number of
segments, on the other hand, usually require longer training and can be more difficult to apply [5,6]. Left ventricular apex, however, should be
probably considered as a 4 segment region, because it can be very frequently only partially involved by the dissynergy [1,4,5,6].
SCORING SCHEMES FOR REGIONAL WALL MOTION ABNORMALITIES Another area that has been the source of confusion pertains to the
different scoring schemes for regional wall motion abnormalities.
One scoring scale has assigned to normally contracting segment the score of 0,
hypokinesis 1, akinesis 2, diskinesis 3, hyperkinesis -1 [2].
More recently a different scoring scale has been suggested assigning to normally contracting segments (or hyperkinetic segment) the score of 1,
hypokinesis 2, akinesis 3, diskinesis 4, and aneurysmal (that is diastotically deformed) segment 5 [5].
A wall motion score index can be derived representing the sum of all scores divided by the number of segments visualized [5]. For this index to be
reliable and meaningful it is important that all or nearly all segments be visualized [5]. The percent of abnormally and/or percent of normally
contracting myocardium can also be calculated. It must be realized, however, that the percent of abnormally contracting myocardium should not be
equated with the percent of infarcted myocardium. EVALUATION OF MYOCARDIAL WALL SEGMENTS Both motion and
thickening of myocardial wall should be evaluated for each segment [2]. To obtain adequate visualization of motion and thickening of each wall segment
a complete and extensive echocardiographic examination should be always obtained by using parasternal, apical and subcostal approaches.All
longitudinal, cross-sectional, 4 chamber and intermediate off-axis views, which can be useful for adequate visualization of anatomy and function of
different myocardial walls, should be adequately explored.
Wall motion and thickening should be analyzed by using real-time, slow-motion and frame by frame evaluation of two-dimensional images, either by
videotape or computer assisted. CONCLUSIONS In conclusion two-dimensional echocardiography allows
identification and definition of site and extension of regional wall abnormalities, either structural or functional.
Complete and extensive examination should be performed in order to achieve adequate visualization of each segment from different views and approaches.
Wall motion abnormalities should be defined both for motion and thickening of myocardial wall.
Complete examinations and adequate standardization should allow precise eva-
Illation of myocardial segments in the majority of patients. REFERENCES 1. Edwards WD, Tajik AJ,
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