Cardiovascular Journal of Africa: Vol 31 No 5 (September/October 2020)

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 31, No 5, September/October 2020

AFRICA

237

and teaching hospital in the country. The study was conducted

between June and October 2015 on a consecutive sample of

patients. The institutional review board approved the study.

Sample size was calculated based on the single population

proportion formula and it was then corrected for a finite

population:

(1–

and adjusted sample size (

) =

(

)/(

), where

is the value from the standard normal

distribution corresponding to the desired confidence level (

= 1.96 for 95% confidence interval),

is the expected true

population proportion (

= 26.6%), taken from another study

reporting prevalence of echocardiographic abnormalities,

is the desired precision (0.05), and

is the finite population

estimated to be 300 at the time of data collection. The adjusted

final sample size was 151.

Socio-demographic data were collected on a questionnaire

through interviewer-administered direct interview of the parent/

guardian, and whenever appropriate, interview of the patient,

after written consent/assent was obtained from each patient and/

or legal guardian. Clinical as well as relevant laboratory data

were extracted from patient records. Patients were excluded from

the study if they declined to consent or if there was established

congenital or rheumatic heart disease.

For echocardiographic examinations, SonoScape SSI-800

ultrasound equipment (SonoScape Medical Corporation,

Shenzhen, China) was used to scan all the patients. An experienced

paediatric cardiologist performed the echocardiographic

examinations in all patients. Standard subcostal, apical four-

chamber, parasternal long- and short-axis as well as suprasternal

view examinations were performed to exclude congenital cardiac

lesions and rheumatic valvular heart disease. LV systolic function

was estimated from the parasternal long-axis view with the

M-mode cursor placed approximately at the level of the mitral

valve leaflet tips (roughly at the level of the papillary muscles).

End-diastolic and -systolic indices were recorded.

Diagnosis of pulmonary hypertension was based on tricuspid

regurgitation velocity of > 3.4 m/s (pressure gradient between

the right ventricle and right atrium of > 50 mmHg).

This

has also been reflected in the 2018 guideline protocol from the

British Society of Echocardiography.

Similarly, estimated right

ventricular (RV)/pulmonary artery systolic pressure refers to the

sum of the tricuspid regurgitation gradient and estimated right

atrial pressure (roughly assumed to be 5–10 mmHg). Pericardial

effusion was graded as minimal if it was seen only in the systolic

phase, mild if it was

10 mm, moderate if it was 10–20 mm, and

severe if it was > 20 mm in the longest diameter.

Myocardial mass was calculated from the left ventricular

end-diastolic indices and indexed to body surface area using a

myocardial mass and myocardial mass index (MMI) calculator.

Normal values and classification of severity of increased

myocardial mass were according to the recommendations of the

American Society of Echocardiography of 2015 and 2005.

23,24

Transmitral diastolic flow velocities were measured in the

apical four-chamber view with the pulsed-wave Doppler sample

volume placed at the tip of the mitral and tricuspid valve leaflets.

Myocardial tissue velocities as well as isovolumic relaxation time

(IVRT), isovolumic contraction time (IVCT) and ejection time

(ET) were measured in the apical four-chamber view with the

pulsed-wave Doppler sample volume placed at the lateral mitral

annulus, septal side of the mitral annulus and lateral tricuspid

annulus. Standard classification of cardiac pathologies was used.

Statistical analysis

Data were entered into the Statistical Package for Social Sciences

(SPSS) version 24 for Mac (IBM Corporation, New York,

USA) and analysed. Descriptive statistics are displayed as

mean

standard deviation (range). Categorical variables are

displayed as frequencies and percentages. The chi-squared test,

non-parametric tests and binary logistic regression method

were used to analyse correlations between patient factors and

observed cardiac pathologies.

Results

One hundred and fifty-one consecutive patients underwent

echocardiographic examination. Age of the patients was 13.0

3.2 (4.0–19.0) years and 83 (55%) were female. Age at diagnosis

of HIV-infection was 5.7

3.3 years (six weeks – 13 years). Age

at initiation of HAART was 7.34

3.54 years (four months – 15

years), while duration of HAART was 59

39.1 (1–126) months.

Baseline socio-demographic, clinical and important laboratory

variables are displayed in Table 1. About 17.8% of the patients

had moderate-to-severe malnutrition based on body mass index

(BMI) for age.

Regarding echocardiographic findings, three patients were

found to have LV systolic dysfunction as defined by LV ejection

fraction of

56% by M-mode measurement.

The LV ejection

fraction of the three patients was between 50 and 52%. One

patient had minimal pericardial effusion. Two other patients

were found to have pulmonary hypertension as evidenced by

tricuspid regurgitation jet velocity > 3.4 m/s or RV-to-right atrial

pressure gradient of > 50 mmHg) with mildly dilated right side

chambers. The estimated RV/pulmonary artery systolic pressure

in both patients was between 60 and 70 mmHg. None of these

patients reported having cardiac symptoms.

Including the above three patientswithLVsystolic dysfunction,

16 patients were noted to have abnormal LV mass index (gm/m

)

compared to the cut-off points for normal values given by the

American Society of Echocardiography (43–95 g/m

for females

and 49–115 g/m

for males) using the linear technique.

Of the 16

patients with abnormal MMI, six had mildly abnormal (96–108

g/m

for females and 116–131 g/m

for males), six had moderately

abnormal (109–121 g/m

for females and 132–148 g/m

for males)

and four had severely abnormal (≥ 122 g/m

for females and

≥ 149 g/m

for males) MMI.

Three of the four patients with

severely abnormal MMI were also the ones who had LV systolic

dysfunction on M-mode echocardiography.

With regard to Doppler and TDI indices, mean transmitral

flow velocity, E/A ratio, was 1.81

0.45 (1.02–2.93). Septal

mitral annulus, E/E

′

, was 6.40

1.30 (0.95–9.87) whereas lateral

mitral annulus, E/E

′

, was 5.9

1.1 (2.2–8.9). Twenty-seven

(17.9%) patients had evidence of LV diastolic dysfunction

(higher E/E

′

values compared to age-adjusted normal values).

Tricuspid lateral annular Et/E

′

t was 3.1

1.0 (1.42–6.15).

Eighteen (11.9%) of the patients had abnormal Et/E

′

t values,

indicating the presence of RV diastolic dysfunction. Nineteen

(12.6%) had tricuspid annular systolic velocity of

9.5 cm/s,

indicating asymptomatic RV systolic dysfunction.

Calculated myocardial performance index (MPI) for

the lateral mitral annulus, septal mitral annulus and lateral

tricuspid annulus was 0.60

0.14 (0.30–0.95), 0.58

0.12

(0.31–0.95) and 0.53

0.20 (0.09–0.96), respectively. Details of