CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 8, September 2012
e2
AFRICA
Fifty healthy, HIV-negative individuals served as controls.
They were recruited after voluntary screening in the HIV clinic
side laboratory to confirm their negative status. Other exclusion
criteria for the HIV-positive patients were also applicable in the
control group. They were recruited to match the age, gender and
body mass index (BMI) profile of the HIV cases.
The research was carried out in accordance with the
Declaration of Helsinki. The study protocol was explained to all
participants and they gave their informed consent. Approval for
the study was obtained from the local Ethics Committee in the
institution.
Patients and controls underwent thorough clinical evaluation
with an emphasis on the cardiovascular system. Venous blood
was collected from all HIV-infected patients for lymphocyte
typing to obtain the CD
4
cell count.
Transthoracic echocardiography was performed using a
Siemens Sonoline S1-450 in the cardiovascular laboratory with
a 3.5-MHZ transducer probe. Each subject was briefed on the
non-invasive nature of the procedure to allay fear and anxiety.
Two-dimensional (2D), M-mode, pulse-wave, continuous-wave
and colour Doppler echocardiography assessment was done
with the subject in the left lateral decubitus position.
12
The
two-dimensional images were obtained in the parasternal long-
and short-axis views, apical and subcostal views.
12,13
Left atrial diameter (LA), aortic size (AO), right ventricular
outflow tract (RVOT), left ventricular end-systolic (LVEDs) and
end-diastolic (LVEDd) diameters, interventricular septum (IVS),
left ventricular posterior wall (LVPW), estimated right ventricle
(
ERV), and end-point septal separation (EPSS) measurements
were obtained from 2D directed, M-mode recordings from
the parasternal long axis.
13
Measurements were taken (in
cm) according to the American Society of Echocardiography
guidelines (leading-edge methodology).
14
The mean of three
measurements was recorded.
Doppler studies included pulmonary velocity (PV), aortic
velocity (AV), transmitral flow, and deceleration time (DT)
measurements. Isovolumetric relaxation time (IVRT) was
obtained from pulse-wave Doppler studies.
13
Echocardiographic
abnormalities, e.g. pericardial effusion, thickening, separation,
valvular lesions such as stenosis, and regurgitations and regional
wall-motion abnormalities were also looked for.
The following definitions were used: dilated left ventricle
refers to LVEDd
>
5.2
cm.
13
Left ventricular systolic dysfunction
was determined by left ventricular fractional shortening (LVFS)
<
28%.
9,15,16
The fractional shortening was computed from the
basic linear measurements using an appropriate formula:
15
LVFS
=
(
LVEDd – LVEDs)
______________
LVEDd
×
100
.
The severity of LV dysfunction was graded based on the
recommendation by the ESC:
15
mild dysfunction, fractional
shortening
=
22–27% ;
moderate
=
17–21%;
severe
<
16%.
The
ejection fraction was calculated using the formula:
15
EF
=
LVEDV – LVESV
______________
LVEDV
×
100
where LVEDV (left ventricular end-diastolic volume)
=
LVEDd
3
,
and LVESV (left ventricular end-systolic volume)
=
LVEDs
3
.
Dilated cardiomyopathy was diagnosed using three criteria: left
ventricular end-diastolic diameter (LVEDd)
>
5.5
cm,
16-18
global
hypokinesia, and fractional shortening (LVFS)
<
28%.
16,19
Isolated right heart dilatation: right ventricle and atrium
larger than left ventricle and atrium, respectively on standard
two-dimensional echocardiography in apical view; right
ventricular end-diastolic dimension
>
3.0
cm with normal left
ventricular size and function.
18,20
Left ventricular diastolic dysfunction was diagnosed in the
presence of any of the following criteria:
21
•
impaired relaxation with an E/A ratio
<
1,
IVRT
>
100
ms
and DT
>
220
ms
•
pseudonormalisation resembling the normal trans-mitral
configuration with regard to the mitral inflow but with normal
or low DT
•
restrictive pattern with E/A ratio
>
2,
IVRT
<
70
ms and DT
<
160
ms.
Pericardial effusion refers to an echo-free space behind the
left ventricle with or without an anterior echo-free space. The
size of the pericardial effusion was defined as follows: small
when the maximum pericardial space at end-diastole was
<
1.0
cm, moderate when the space was
≥
1.0
cm but
<
2.0
cm, and
massive/severe when the pericardial space was
≥
2.0
cm between
the pericardial layers.
22,23
Results
A total of 100 HIV-positive cases and 50 healthy control subjects
were recruited for the study. The cases comprised 57 females
(57.0%)
and 43 males (43.0%), while the controls included 28
females (56.0%) and 22 males (44.0%). The gender distribution
was comparable (
χ
2
=
0.01;
p
=
0.913).
The mean age and BMI
were not statistically different.
The most common symptoms relevant to the heart were
cough (23%), palpitations (11%) and shortness of breath (7%).
Most were, however, non-specific as many of the patients
had associated anaemia, infections and pulmonary disease,
which could have accounted for these symptoms. Only two
patients had overt symptoms of heart failure (dyspnoea at rest,
orthopnoea, paroxysmal nocturnal dyspnoea, leg swelling, tender
hepatomegaly), while one had features of massive pericardial
effusion. All three had a CD
4
count less than 100/
µ
l.
The mean pulse rate was significantly higher in the cases than
the controls (87.04
±
13.04
and 78.56
±
6.22,
respectively;
p
=
0.000) (
Table 1). There was no significant difference between
the systolic blood pressure (SBP) of the cases and controls.
The diastolic blood pressure (DBP) of the cases was, however,
significantly lower than that of controls (70.59
±
7.39
and 74.60
±
7.27,
respectively;
p
=
0.002).
The CD
4
count ranged from 7.00 to 1 481.0/
µ
l with a mean
of 232.0 ± 214.8/
µ
l.
TABLE 1. DEMOGRAPHICAND CLINICAL
FEATURES OF THE STUDY POPULATION
Features
Cases
(
n
=
100)
Controls
(
n
=
50)
t
p
Age (years)
33.20
±
7.67 31.72
±
9.71 1.016 0.311
BMI
21.41
±
4.35 22.56
±
2.76 2.890 0.091
BSA (m
2
)
1.66
±
0.19 1.68
±
0.17 0.508 0.612
Pulse rate (beats/min) 87.04
±
13.04 78.56
±
6.22 4.348 0.000*
DBP (mmHg)
70.59
±
7.39 74.60
±
7.27 3.146 0.002*
SBP (mmHg)
111.56
±
11.53 113.00
±
12.98 0.687 0.493
Values are mean
±
SD. BMI: body mass index; BSA: body surface area;
DBP: diastolic blood pressure; SBP: systolic blood pressure. SD: standard
deviation; *
p
<
0.05
is statistically significant.
