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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 1, January/February 2016
26
AFRICA
Ninety patients who satisfied the study criteria were recruited
after informed consent was obtained from their parents and
other legal caregivers. Ethical approval was obtained from the
ethics committee of the UNTH, Ituku-Ozalla, Enugu. Informed
consent was obtained from parents or guardians of the children
and older children, respectively.
All the sera from potential control subjects were screened for
HIV infection using the Retrocheck
®
HIV testing kit (Nicholas
Biotech, Texas, USA). Only those who tested negative were
recruited for the study. The investigator administered a standard
pre-test questionnaire to obtain biodata, demographic data and
clinical history, including medication history, HIV and AIDS
category based on CDC classification system, and type and
duration of HAART. All subjects and controls also underwent a
thorough physical examination.
The height and the weight were obtained using Hanson’s
model H89 Orange
®
stadiometer and weighing scale respectively,
according to standard procedures.
11
Systolic and diastolic blood
pressure measurements were taken on the right arm using
an appropriately calibrated mercury sphygmomanometer with
appropriate-sized cuff. The average of three readings was taken
10 minutes apart to represent the blood pressure estimate.
Full blood counts (FBC) were obtained on the I-STAT auto-
analyser, and counter for haemoglobin concentration, leukocyte
count and differentials, and erythrocyte sedimentation rate
(ESR). CD4
+
cell counts were obtained by auto-separation.
Echocardiography was done using the Hewlett-Packard
SONO 2000 machine, which has a transducer with multi-
frequency in the range 5.5–12 MHz for children, a video recorder
and a print-out processor. It has capabilities for M-mode,
two-dimensional, pulsed wave and continuous-wave Doppler
echocardiography. Echocardiography was performed on each
child by two of the investigators and also interpreted to reduce
intra-observer bias. These operators were blinded to the HIV
and clinical status of the study subjects. For each examination,
standard procedures and techniques were applied to windows.
13
The younger subjects who were not cooperative in the presence
of their caregiver or parents (usually those under two years) were
pacified with toys or sedated with a mild short-acting sedative,
chloral hydrate, as appropriate.
Echocardiographic measurements were taken in centimetres
(cm) using the American Society of Echocardiography (ASE)
guidelines for leading-edge methodology.
14
The mean of three
measurements was recorded and normative values for the
echocardiographic measures, according to body surface area
(BSA), were based on the ASE reference, as there were no local
data available in this age group known to the authors at the time
of the study.
Fractional shortening (FS) was calculated using the formula:
FS (%)
=
(LVEDd–LVESd)
×
100
___________________
LVEDd
LVEDd
=
left ventricular end-diastolic dimension, LVESd
=
left
ventricular end-systolic dimension. The normal range of FS is
28–41%, with a mean of 33
±
5%.
Ejection fraction, EF (%)
=
stroke volume
×
100
________________
LVEDd
The normal range of EF is 45–90%, with a mean of 62
±
10%.
Stroke volume (SV)
=
LVEDV–LVESV.
Left ventricular end-diastolic volume (LVEDV)
=
LVEDd
3
Left ventricular end-systolic volume (LVESV)
=
LVESd
3
Depressed LV systolic function is a fractional shortening of
≤
28%, or ejection fraction of less than 40% with normal left
ventricular dimensions.
14
Statistical analysis
Statistical analysis was done using the Statistical Package for
Social Sciences (SPSS) version 18.0. Descriptive statistics for
baseline demographic data are presented as both mean and
standard deviation (SD) for continuous variables, or percentages
for discrete variables. The non-parametric chi-squared (
χ
2
) test
was used to test comparable categorical variables, while one-way
ANOVA was used for continuous variables. A value of
p
<
0.05
was considered statistically significant. Pearson’s correlation
and multiple linear regression analysis were used to assess the
relationship between left ventricular systolic dysfunction (LVSD)
and the variables affecting it.
Results
Table 1 shows the clinical and laboratory characteristics of the
study participants. There were 90 children with HIV and AIDS,
and 90 normal children were used as controls. Of the 90 with
HIV and AIDS, 16 had clinical AIDS.
There was no significant gender difference (
χ
2
=
0.654,
p
=
0.06) or difference in mean age between the groups. However
there were significant differences in the mean weight, height,
body mass index (BMI), respiratory rate (RR), heart rate (HR),
systolic blood pressure (SBP), diastolic blood pressure (DBP),
total white blood cell count, erythrocyte sedimentation rate
(ESR) and CD4
+
cell count between the controls, HIV and
AIDS groups. The controls had higher weight, height, BMI,
haemoglobin levels and CD4
+
cell counts than the HIV and
AIDS groups. The mean RR, HR and ESR were significantly
higher in the HIV and AIDS groups than in the controls (
p
<
0.001). The AIDS group had severely depressed CD4
+
cell counts
compared to the other groups (
χ
2
=
5.6,
p
=
0.01).
Table 2 demonstrates the echocardiographic characteristics
of the study participants with regard to systolic function of
the heart. There was a significant difference in the mean left
ventricular mass index (LVMI) of the HIV and AIDS groups
compared with the controls. The LVMI was higher in the HIV
and AIDS groups than in the controls. The mean FS and EF
were significantly lower in the HIV and AIDS groups compared
with the controls (
p
0.001). The mean LVEDd and LVESd were
significantly higher in the HIV and AIDS groups than in the
controls. LVESd was highest in the AIDS group (Table 2). The
prevalence of LVSD was highest in the AIDS group (81.2%),
followed by the HIV-positive group (27%), and least (2.2%) in
the controls. These differences were statistically significant (
χ
2
=
1.23,
p
=
0.03).
Table 3 shows the correlation of important determinants of
cardiac systolic function in the HIV and AIDS groups. Age,
duration of treatment, CD4
+
cell count (in the HIV group) and
pulse rate correlated positively with systolic dysfunction, while
duration of treatment, diastolic blood pressure, and CD4
+
cell