الفهرس 
Heart FailureOnly 14 pages are availabe for public view
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Abstract
Heart failure is a complex clinical syndrome
characterized by impaired myocardial performance and
progressive activation of neuroendocrine system leading to
circulatory insufficiency and congestion.
Cardiac resynchronization therapy (CRT) is now an
established treatment for patients with advanced heart
failure. Apart from clinical benefits, improvement of left
ventricular (LV) systolic function and associated LV
reverse remodeling have been well reported.
Numerous studies have demonstrated the efficacy of
CRT in treatment of patients with advanced heart failure.
One of the earliest and most common applications of
clinical echocardiography is evaluation of left ventricular
(LV) function and size. Three-dimensional echocardiographic
(3DE) techniques showed better
reproducibility than two - dimensional (2D) echocardiography
and narrower limits of agreement for
assessment of LV function and size in comparison with
reference methods, mostly cardiac magnetic resonance
(CMR) imaging.
The rate of approximately 30% of inadequate
responders remains an unsolved problem. One approach to
improve outcome may be determination of the degree of
asynchrony before CRT as a predictor for CRT response.
Conversely, the focus may be on an improved positioning
of the left ventricular (LV) lead.
Summary
140
To improve outcome and reduce the proportion of
CRT non-responders, three different and complementary
approaches have been proposed: optimization of patient
selection; optimization of LV lead placement and
optimization of the programming of the CRT device.
The choice of the LV pacing site remains an
important issue in patients requiring CRT. The importance
of 3DE in optimal LV pacing lead position was discussed in
several studies comparing response to CRT in patients with
the LV pacing lead at the segment with the maximum
mechanical delay to patients with the LV pacing lead at
other segments.
We aimed at our study to define the impact of three
dimensional echocardiography in determining the optimal
LV pacing lead position as a method of CRT optimization.
The current study was conducted on 30 patients with
advanced congestive heart failure who had received CRT in
Ain Shams University Hospitals in the period from 2012 to
2014.
All patients were subjected to: thorough history
taking with particular stress on age, gender, risk factors,
history of previous tachyarrhythmia, symptoms including
dyspnea were classified by New York Heart Association
(NYHA) classification, and Minnesota living with heart
failure questionnaire (MLHFQ). Also they underwent
general and local examination including heart rate, blood
pressure, body mass index, and body surface area. They
were followed up after mean 5 months after the therapy.
Summary
141
We made a detailed analysis of the 16 segments of
the LV times to reach the minimal volume and determined
the latest wall (by having at least 2 delayed segments) to
reach the minimum volume, the CRT was inserted blindly
to our results and the patients were classified into two
groups (A and B):
Group A: Patients were included in group A when they
underwent CRT LV lead implantation in the
coronary sinus vein tributary which
corresponded to or approximate the latest
contracting segment of the LV identified by
preprocedural 3DE.
Group B: Others were included in group B when they
underwent CRT LV lead implantation in any
coronary sinus vein tributary which was not
correspond to or approximate the latest
contracting segment of the LV identified by
preprocedural 3DE.
Patients presenting with reductions of LV endsystolic
volume of >10% (improved LV remodeling) were
defined as volumetric responders to CRT 57%, whereas
those presenting with lesser degrees of reduction were
termed non-responders.
Data were collected, verified, revised and edited,
then statistically analyzed.
Our findings demonstrate that the response to CRT
resulted in significant improvement of NYHA class, six
Summary
142
minute walk test (p-value <0.001, 0.005), significant
increase in LV EF by 2D and 3D echocardiography (P value
<0.001 for both) with significant increase in LV SV
measured by 3D echocardiography (p value 0.001),
significant reduction of LA diameter (p-value 0.03),
LVESD diameter, LVESV by 2D , however there was no
any statistically significant difference between group A and
B in the percentage of changes of all these parameters.
Unfortunately we concluded the absence of
additional benefit of selecting LV lead position pre CRT
insertion to be concordant with the latest myocardial
segment in reaching the minimal systolic volume assessed
by 3D echocardiography.