CARDIOVASCULAR JOURNAL OF AFRICA • Vol 22, No 4, July/August 2011
AFRICA
183
The institutional review board of the hospital approved the
study protocol. All participants gave written informed consent.
This investigation was in accordance with the Declaration of
Helsinki.
Direct stenting or stenting after successful angioplasty was
performed in all the participants according to published guide-
lines.
13
All patients received heparin to a target activated throm-
bin time level of 200–300 sec, and also clopidogrel in standard
doses.
Echocardiographic data were obtained using a commer-
cially available ultrasound system Vivid-3 (GE) equipped with
a 3-MHz transducer. Measurements were obtained by averaging
values recorded in three consecutive cycles, according to the
current American Society of Echocardiography guidelines.
14
For two-dimensional and M-mode echocardiography, 2-D
images were obtained in standard parasternal and apical views.
All patients were examined at rest in the left lateral decubitus
position.
The LV end-diastolic and end-systolic dimensions (LVEDD
and LVESD) were measured at the level of the mitral leaflet tips
from the parasternal long-axis with two-dimensional targeted
M-mode echocardiography. LVEF was calculated from the apical
two- and four-chamber views using the modified Simpson’s rule.
The regional wall motion abnormality (RWMA) score of
the LV was assessed for each LV segment individually, and the
wall motion abnormality score index (WMSI) was obtained
using the 16-segment model, according to the American Society
of Echocardiography recommendations.
14
Higher scores were
considered for more severe wall motion abnormalities (1:
normal, 2: hypokinesis, 3: akinesis, 4: dyskinesis, 5: aneurysmal).
For RV systolic functional assessment, the tricuspid annular
plane systolic excursion (TAPSE) was measured using two-
dimensionally guided M-mode imaging from the apical four-
chamber view.
Mitral inflow velocities were measured with pulsed-wave
colour Doppler echocardiography, with the sample volume
positioned between the tips of the mitral leaflets in the apical
four-chamber view. Peak early diastolic velocity (E), peak late
diastolic velocity (A), E/A ratio and deceleration time (DT) were
obtained.
Mitral inflow propagation velocity (Vp) was measured as the
maximum slope of the first aliasing velocity during early filling
from the mitral valve plane to 4 cm distal to the LV cavity in the
apical four-chamber view using colour M-mode Doppler.
Pulmonary vein systolic flow velocity (PVs) and diastolic
flow velocity (PVd) were measured from the apical four-cham-
ber by placing a sample volume in the right upper pulmonary
vein with Doppler echocardiography. Isovolumetric contraction
time (IVCT), isovolumetric relaxation time (IVRT) and ejection
time (ET) were assessed by simultaneously measuring the flow
into the LV outflow tract and the mitral inflow, using Doppler
echocardiography. The index of myocardial performance (IMP
or Tei index) was calculated by dividing the sum of IVRT and
IVCT by ET.
Pulsed-wave TDI was performed by activating the tissue
Doppler function in the same echocardiographic machine. Mitral
annulus velocities (myocardial systolic and diastolic velocities)
were measured using the pulsed-wave TDI technique, by placing
a 1–2-mm sample volume at the levels of septal, lateral, inferior,
anterior and posterior annulus.
Peak systolic velocity of the mitral annulus (Sa), and early
(Ea) and late diastolic (Aa) velocities of the mitral annulus were
determined from septal, lateral, inferior, anterior and posterior
aspects. Peak systolic velocity of the tricuspid annulus (TA-Sa)
was also derived from pulsed Doppler tissue imaging of the
lateral tricuspid annulus.
Statistical analysis
Continuous variables are presented as means
±
standard devia-
tions (SD) and categorical data are expressed as frequencies
and percentages. Comparisons of continuous variables pre and
post PCI were carried out using the paired-samples
t
-test. The
Wilcoxon signed rank test was used to test for the difference
between the mean RWMA scores before and after PCI. The
statistical software SPSS-13 (Chicago, IL, USA) for Windows
was used for all analyses;
p
-values
<
0.05 were considered statis-
tically significant.
Results
A total of 21 patients who had had successful PCI were consid-
ered for the study analysis. Baseline characteristics of partici-
pants are summarised in Table 1. LVEF, RWMI and peak systolic
velocities remained unchanged 48 hours following elective PCI
(Table 2). The index of myocardial performance did not change
(Table 2). Vp improved significantly early after PCI (
p
=
0.008).
Other diastolic indices did not show improvement (Table 3).
Discussion
This study presents a comprehensive echocardiographic assess-
ment of regional and global myocardial function, both systolic
and diastolic, following blood flow restoration with PCI elec-
tively performed in patients with stable CAD. Our findings
indicate that the propagation velocity of early flow into the LV
cavity (Vp), measured by colour M-mode Doppler, was the most
sensitive index to recover after successful PCI.
LV ejection fraction calculated by the biplanar Simpson’s
method, along with other parameters of myocardial systolic
function including the regional wall motion index evaluated by
2-D and TDI-derived systolic myocardial velocities at the mitral
(Sa) and tricuspid annulus (TA-Sa), did not change significantly
TABLE 1. BASELINE CHARACTERISTICS
OF THE PATIENTS
Study population (
n
=
21)*
Age (years)
54.05
±
10.08
Male (%)
14 (66.6)
BMI (kg/m
2
)
25.72
±
3.97
Heart rate
76.05
±
11.36
LVESD (cm)
3.27
±
0.53
LVEDD (cm)
5.03
±
0.42
Angiographic results (%)
Mono-vessel involvement
12 (57.1)
Two-vessel involvement
6 (28.6)
Three-vessel involvement
3 (14.3)
*Means
±
standard deviation. BMI: body mass index; LVESD: left
ventricular end-systolic diameter; LVEDD: left ventricular end-
diastolic diameter.
