CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 9, October 2012
484
AFRICA
transverse aortic arch would provide a simple tool to improve the
accuracy of diagnosing coarctation.
Previousinvestigationshaveproducedafewechocardiographic
indices, which were validated in a limited group of patients, to
evaluate the condition of patients with aortic coarctation.
4,18-20
However, the age groups of the patients differed and the
various echocardiographic indices assessed were incomplete.
Therefore we aimed to evaluate the changes in a complete list
of echocardiographic profiles in patients with aortic coarctation
before and after stenting, and to determine the diagnostic value
of these indices as an indicator of aortic coarctation.
Methods
This prospective study was conducted on 23 consecutive patients
with the diagnosis of aortic coarctation who were referred to
Rajaei Heart Centre (affiliated to Tehran University of Medical
Sciences), Tehran, Iran, from April 2008 to August 2009. For
this purpose, 40 patients with a definite diagnosis of aortic
coarctation, based on an angiographic study, were referred to the
ECHO Research Centre of the hospital for further assessment.
All cases had primary unoperated coarctation. Patients
with other concomitant lesions, including aortic stenosis or
regurgitation, patent ductus arteriosus, anomalies of the head and
neck vessels, and long-segment aortic coarctation or hypoplastic
arch were excluded.
According to their lesions, these 40 patients were candidates
for balloon angioplasty, and stenting of the aortic coarctation was
performed on all of them. Among these patients, 23 who had
been proven to have no gradient and residual stenosis at the time
of stenting were enrolled into the study.
In addition to baseline and demographic variables (e.g. age,
gender, blood pressure and length of stenosis), the characteristics
of stenting, including length and width of stent, length and
width of balloon, and before- and after-stent peak gradient of
the catheter were recorded for all patients. All gradients were
directly measured during catheterisation.
Informed written consent was obtained from all patients. The
research project was approved by the ethics committee of Tehran
University of Medical Sciences.
Echocardiographic evaluation
Echocardiographic assessment was done twice on all patients,
24
hours before and 24 hours after stenting. Two-dimensional
and Doppler echocardiographic imaging studies were performed
using a Vivid 3 Imaging System (GE, USA) in accordance with
institutional guidelines. All echocardiographic studies were done
by one echocardiologist before and after stenting.
Both the abdominal and descending aorta were evaluated
during Doppler echocardiography. The standard suprasternal
position was used to measure the maximum velocity across the
coarctation site and then continuous-wave Doppler recordings
were obtained. Pulsed-wave Doppler from the standard subcostal
view was also performed to document the flow pattern of the
abdominal aorta.
The measurements obtained in the abdominal and/or
descending aorta were peak systolic velocity (PSV) (m/s), early
diastolic velocity (EDV) (m/s), late diastolic velocity (LDV)
(
m/s), systolic acceleration time (AT) (m/s), pressure half-time
(
PHT) (m/s), mean velocity (m/s), mean of peak gradient (mean
PG), diastolic velocity/systolic velocity (D/S ratio velocity),
velocity–time integral (VTI), time to peak systolic velocity
(
m/s), pulse delay, and pulsatility index (PI). Samples of
pulse-wave Doppler echocardiography of the abdominal and
descending aorta are shown in Figs 1 and 2, respectively.
All studies, including pre- and post-stenting profiles, were
performed with simultaneous electrocardiographic monitoring
(
ECG based), and the onset of diastole was assumed at the end of
the electrocardiographic T wave. Moreover, three measurements
Fig. 1. Continuous-wave Doppler echocardiography of
the abdominal aorta. AT: systolic acceleration time is
measured from the onset of the systolic upstroke to the
systolic peak. DT: deceleration time is measured from
Peak E velocity to the point where the slope of the slow-
ing flow would intercept the baseline. EDV: early diastolic
velocity: maximum diastolic velocity on early diastole.
LDV: late diastolic velocity: maximum diastolic velocity
on late diastole. PHT: pressure half-time (of diastole) is
the time interval for the peak diastolic pressure gradient
to be reduced by one half. PSV: peak systolic velocity:
maximum systolic velocity. TSV: time to peak systolic
velocity: time beginning from onset of QRS complex to
peak systolic velocity. VTI: velocity time integral: the area
under the curve, shown in both systole and diastole.
Fig. 2. Continous-wave Doppler echocardiography of
descending aorta. AT: systolic acceleration time, DT:
deceleration time, EDV: early diastolic velocity, LDV: late
diastolic velocity, PHT: pressure half-time (of diastole),
PSV: peak systolic velocity, TSV: time to peak systolic
velocity.
