الفهرس 
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Abstract
The aim of this work was to identify the echocardiographic
predictors of outcome of aortic valve
replacement for patients with chronic aortic regurgitation
and also to study the serial changes which occurred
following operation.
For this aim sixty three patients with isolated
chronic aortic regurgitation or predominant aortic
regurgitation were studied preoperatively, at early
postoperative period (within month) and late postoperatively
(more than six months). Each patient was
subjected to thorough clinical, electrocardiographic,
radiologic and echocardiographic studies.
Patients
outcome into
improvement in
were classified according to their
two groups, satisfactory, who showed
their functional class with normal
or above normal ejection fraction and unsatisfactory,
who
with
showed deterioration in their functional class
below normal ejection fraction. Also patients
who died were considered to be in the unsatisfactory
group. On this basis we had 46 patients with satisfactory
outcome and 17 patients with unsatisfactory outcome
(including 3 patients died).- 174 -
It was found that the most i_ndependent M-mode predictors
of outcome were, the fractional shortening, the radius
to ’dall thickness ratio and the cross sectional area.
By these three variables trogether the outcome could
be predicted with ~3-7% accuracy, 100% sensitivity
and 91. 3% specificity. The best fa ted cut off values
at which accurate classification could be made were
28% for fractional shortening, 3. 6 for radius to wall
thickness ratio and 29 em’ for the cross-sectional
area. For the two Dimensional echocardiographic predictors,
the most ir1dependent predictors were the fractional
change in cavity area, the left ventricular end systolic
volume index and the mean rate of circumferential
area shortening.
By these three variables together, outcome could
be predicted with 96.8% accuracy, 100% specificity
and 88.2% sensitivity. The best fated cut off values
at which accurate classification could be made were
100 cc/m2 for left ventricular end systolic volume
index, 37% for the fractional change in cavity area
and 1. 3 eire /sec for the mean rate or circumferential
area shortening.
Doppler variables had no independent predictive
value, but by the univariate analysis of the Doppler- 175 -
variables, regurgitant fraction and left ventricular
end diastolic pressure had non independent predictive
value.
Studying all independent M-mode, two dimensional
and Doppler predictors by multivariate analysis, the
following variables were found to have the most independent
predictive value, the fractional change in cavity
area (FAS), the left ventricular end systolic volume
index (LVESVI) the mean rate of circumferential area
shortening (mVcF’’A’’) and the M-mode cross sectional
area. By constructing an equation using these independent
predictors outcome could be predicted with 98.4%
accuracy, 9 4. 1% sensitivity and 100% specificity.
The equation was constructed as following:
11.8-0.724 (FAS) + 9.81 (mVcFA) + 0.107 (ESVI)
0.453 (CSA) when the result of the equation was
negative good outcome could be predicted and when
it was positive bad outcome could be predicted.
* We then studied, the prognostic significance
of the preoperative fractional shortening and left
ventricular end systolic dimension. For this reason
patients were classified into two main groups, group
I with FS > 28% and group II with FS < 28% and each group
was subdivided into subgroups according to the LVESD.
Group I involved 37 patients with LVESD < 5.5 em and only
two patients with LVESD > 5.5 em and group II involved - 176 -
patients with LVESD < 5.5 em and 12 patients with LVESD
> 5.5 em.
It was found that patients with ;Jreopera t i ve
FS > 28% and LVESD < 5.5 em had the best outcome and
also patients in whom FS was less than 28% but with
LVESD < 5.5 em. While patients with FS < 28% and LVESD >
5.5 em were found to have the worst outcome (25% death,
58% became in functional III and IV, with below normal
ejection fraction, larger end systolic volume, larger
left ventricula~ end higher
cross sectional area).
Studying the
diastolic dimensions and
serial changes which occurred
follm.Jing the aortic valve replacement for patients
with chronic aortic regurgitation it was found that
there was improvement of left ventricular systolic
functions, reduction of left ventricular size, regression
of hypertr’ophy and reduction of end systolic stress.
There was early decrease in systolic function
and this was explained by the decrease in preload
followed by later increase in the systolic function
and this was explair2d by the decrease in the afterload,
regression of hypertrophy and actual improved
contractility .Left ventricular size showed significant decrease
and most of this decrease occurred at early pstoperative
period.
Regression of hypertrophy was less prompt and
continued till late postoperative periods.
End systolic circumferential stress showed
non significant decrease while end systolic meridional
stress showed significant decrease in the satisfactory
group of patients with non significant change in the
unsatisfactory group of patients and this might explain
the persistent left ventricular dysfunction in the
unsatisfactory group of patients.
Patients with unsatisfactory
residual dilatation and hypertrophy,
and reduced systolic
outcome showed
increased
functions
endsystolic stress on
the contrary to patients with satisfactory outcome.