CARDIOVASCULAR JOURNAL OF AFRICA • Vol 21, No 5, September/October 2010
AFRICA
253
sive therapy or the persistent elevation of blood pressure above
140/90 mmHg on two or more occasions with the patient in a
sitting position for at least five minutes. Patients were subjected
to history taking, physical examination and simple clinical
investigations. Demographic parameters, including age, gender,
occupation and associated symptoms were obtained. The weight
was taken in light clothing to the nearest 0.5 kg, while the height
was taken to the nearest 1 cm using a stadiometer.
Echocardiography
All subjects had echocardiography performed on them with
the use of a SUIS APOGEE ultrasonograph with a 3.5-MHz
transducer. Echocardiography was performed according to the
recommendations of the American Society of Echocardiography
(ASE).
14
The patients were placed in the left lateral decubitus
position. The left parasternal view was used to take the follow-
ing measurements: right ventricular wall dimension and right
ventricular end-diastolic diameter, interventricular septal diam-
eter (IVSD), LV end-diastolic diameter (LVEDD), posterior wall
diameter (PWD) and left atrial dimension (LAD).
LV mass was calculated using the Devereux formula
15
and
the LVMI was derived. Left ventricular hypertrophy was defined
as a LVMI above 125 g/m
2
for both genders, as used in the
Framingham study for the evaluation of LVH in subjects with
hypertension.
16
The left ventricular ejection fraction was calcu-
lated using the M-mode measurements of the left ventricle.
The pulse Doppler studies were reported from the apical four
chambers or alternatively the parasternal short-axis view. The
Doppler sample volume was placed at the level of the tricuspid
annulus and recordings from three cycles were averaged. The
following measurements were taken: peak early E wave, peak
late atrial A diastolic velocities and velocities time intervals.
At the right ventricular outflow tract, the maximum and mean
pulmonary systolic pressures were obtained. Similar measure-
ments were made at the mitral valve annulus and at the left
ventricular outflow tract. All the recordings were obtained for
three cycles and their averages were used for calculation. All
measurements were taken with the subjects in quiet respiration.
Statistical analysis
Data were analysed using the Statistical Package for Social
Sciences SPSS 16.0, (Chicago, Ill). Quantitative data were
summarised using means
±
standard deviation, while qualita-
tive data were summarised using percentages and proportions.
Comparisons between groups were made using independent
t
-test and chi-square as appropriate. Correlation analysis was
done for some diastolic and systolic parameters. Statistical
significance was taken as
p
<
0.05.
Results
The hypertensive subjects were well matched in age and gender
(
p
>
0.05). The mean age of the hypertensive subjects was 57.5
±
13.3 years while the mean age of the control subjects was 55.9
±
11.3 years (
p
>
0.05). The gender distribution was also similar
between the two groups. As expected, the systolic blood pressure,
diastolic blood pressure and pulse pressure were significantly
higher among the hypertensive subjects than the controls (158.8
±
18.1, 92.9
±
13.1, 59.51
±
17.9 vs 117.8
±
10.7 mmHg, 76.6
±
8.5 mmHg, 41.1
±
4.5 mmHg, respectively;
p
<
0.001). The
hypertensive subjects also had a higher body mass index than the
controls (27.5
±
5.9 vs 24.8
±
4.5 kg/m
2
, respectively;
p
<
0.05)
As shown in Table 2, the echocardiographic parameters
show significant variations between the hypertensive subjects.
The left ventricular chamber and wall dimensions were signifi-
cantly higher among the hypertensive subjects than the controls.
However, the right ventricular chamber dimensions were higher
in the controls than the hypertensive subjects (23.1
±
3.1 vs 20.7
±
8.0 mm, respectively;
p
<
0.001).
The pulsed Doppler echocardiographic measurements are
shown in Table 2. The pulmonary systolic velocities were simi-
TABLE 1. DEMOGRAPHICAND CLINICAL PARAMETERS
OF STUDY POPULATION
Variable
Hypertensives
(
n
=
100)
Controls
(
n
=
50)
p
-value
Mean age (years)
57.5
±
13.33 55.9
±
11.33 0.12
Mean SBP (mmHg)
158.8
±
18.1 117.8
±
10.7
<
0.001**
Mean DBP (mmHg)
92.9
±
13.1
76.6
±
8.5
<
0.001**
Gender (M/F)
65/35 (65/35%) 28/22 (56/44%)
0.404
Mean BMI (kg/m
2
)
27.6
±
5.9
24.8
±
4.5
0.035
Mean BSA (/m
2
)
1.8
±
0.2
1.7
±
0.2
0.19
Mean PP (mmHg)
59.51
±
17.9
41.1
±
9.3
<
0.001**
**Statistically significant. SBP: systolic blood pressure, DBP: diastol-
ic blood pressure, M: males, F: females, BMI: body mass index, BSA:
body surface area, PP: pulse pressure.
TABLE 2. ECHOCARDIOGRAPHIC PARAMETERS OF
STUDY PARTICIPANTS
Variable
Hypertensives Controls
p
-value
Mean IVSD (mm)
12.2
±
2.6 10.2
±
0.7
<
0.001**
Mean LVEDD (mm)
47.3
±
7.6 45.0
±
5.2
<
0.001**
Mean PWT (mm)
11.8
±
2.5
9.6
±
1.3
<
0.001**
Mean RVD (mm)
20.7
±
8.0 23.1
±
3.1
<
0.001**
Mean AOD (mm)
30.6
±
4.8 32.5
±
3.3
<
0.001**
Mean LAD (mm)
37.0
±
8.1 30.8
±
4.1
<
0.001**
Mean mitral E (m/s)
0.62
±
0.22 0.62
±
0.27
<
0.05*
Mean mitral A (m/s)
0.68
±
0.17 0.54
±
0.35
<
0.05*
Mean mitral E/A
0.91
±
0.75 1.24
±
0.31 0.035*
Mean DT (msec)
209.0
±
54.7 148.0
±
27.9
<
0.001**
Mean IVRT
105.4
±
28.4 82.0
±
9.6 0.072
Mean TE (m/s)
0.39
±
0.12 0.46
±
0.16 0.022**
Mean TA (m/s)
0.44
±
0.11 0.38
±
0.11 0.032**
Mean peak pulm vel (m/s)
0.61
±
0.16 0.80
±
0.2 0.442
Mean pulm vel (m/s)
0.61
±
0.16 0.64
±
0.26 0.36
Mean tricuspid E/A
0.89
±
0.36 1.29
±
0.30 0.04**
Mean FS (%)
46.6
±
7.6 39.1
±
5.2
<
0.001**
Mean LVMI (g/m
2
)
121.1
±
35.9 87.6
±
15.5
<
0.001**
**Statistically significant. IVSD: interventricular septal dimension
in diastole, LVEDD: left ventricular end-diastolic dimension, PWT:
posterior wall thickness in diastole, RVD: right ventricular diastolic
dimension, AOD: aortic root dimension, LAD: left atrial dimension,
Mitral E/A: mitral E/A ratio, DT: deceleration time, IVRT: isovolu-
mic relaxation time, TE: tricuspid E (early) wave velocity, TA: tricus-
pid A (late atrial) velocity, Peak pulm vel: peak pulmonary systolic
velocity, Mean pulm vel: mean pulmonary velocity, Tricuspid E/A:
tricuspid E/A ratio, FS: fractional shortening, LVMI: left ventricular
mass index.
