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All the participants were interviewed by the researcher using a structured questionnaire that sought information about demographic data, history of suggestive of severity sickle cell anaemia (magnitude of crises, admissions, blood transfusion) and symptoms of cardiac dysfunction. A detailed general examination was done and positive findings recorded. Anthropometric measurements were taken i.e. weight in kilograms (without shoes) using the weighing scale and height in meters using the stadiometer. This was done with the patient standing barefoot. Body Mass Index (BMI) was calculated (the patient’s weight divided by the square of the height) and recorded in kg/m².

A detailed cardiovascular system examination was done. The patients’ pulses were assessed for rate, rhythm, character and synchrony. Blood pressure was measured using a standard mercury sphygmomanometer (adult cuff size) with the patient in the supine and sitting positions.

Korotkoff sounds I and V were considered as the systolic and diastolic blood pressures respectively and recorded in mmHg. This was done after 5-minute rest using the right and left upper limbs. Two additional recordings were made using the limb with the higher value. The average in this limb was calculated to give a representative value.

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The jugular venous pulsation was measured and documented. The precordium was examined, apex beat localized and the presence of thrills in the various areas documented. The precordium was also auscultated for the presence of the normal first and second heart sounds, third and fourth heart sounds and a loud A2 or P2. The lung bases were also auscultated for crepitation.

Blood samples were taken from patients by the investigator, put in plain specimen bottles and sent to the Chemical Pathology laboratory for analysis. The following were assayed for: serum creatinine, uric acid, total bilirubin and alanine transaminase. Two milliliters of blood sample was also collected in an EDTA bottle for determination of packed cell volume at the Hematology laboratory of JUTH.

Each subject had a twelve lead electrocardiography performed by the ECG technician in the ECG laboratory using GE MAC1200 model electrocardiography machine at a speed paper of 25mm/s and standardized at 0.1mv/mm. the electrocardiogram was analyzed independently by the researcher under the guidance of the supervisor.

Left ventricular function of the subjects was assessed using echocardiography by the investigator. The procedure was performed with the subject in left lateral recumbent position.

Images were obtained in the parasternal long and short axis views and apical views. A two dimensional, M-Mode, pulse wave, continuous wave and colour Doppler ECG-gated echocardiographic assessment done. Cardiac measurements was done using the American Society of Echocardiography guidelines⁸⁷. Diastolic measurement was taken at the peak of the R wave while systolic measurements at the peak of the T wave. The ejection fraction (EF) and fractional shortening (FS) were taken as measures of systolic function. Diastolic function was evaluated by studying the filling dynamics of the left ventricle. The mitral inflow velocities was

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measured from the apical four chamber view with pulsed-wave Doppler and with the sample volume positioned at the tip of the mitral valve leaflets.

These inflow characteristics were quantified by measuring the trans-mitral "E" wave velocity (peak early mitral inflow velocity) and the "A" wave velocity (peak atrial mitral inflow velocity).

The E/A ratio and E-wave deceleration time (DT) were taken as measures of diastolic function.

Average of measurements in three cardiac cycles was taken with simultaneous ECG recording.

Other parameters measured included aortic root diameter (AO), left atrial diameter (LAD), left ventricular diameter in end systole (LVIDS) and end diastole (LVIDD), left ventricular volume in end systole (LVESV) and end diastole (LVEDV), interventricular septum in systole (IVSS) and diastole (IVSD), left ventricular posterior wall in systole (LVPWS) and diastole (LVPWD), anterior mitral leaflet excursion (AMVLexc), E-F slope (EFs), E-point septal separation (EPSS) and mitral valve area (MVA).

Left Ventricular mass (LVM) was calculated using the Devereux formula⁸⁸. LVM (g) = 1.04 [(LVEDD + IVS + LVPW)³ – LVEDD³ ] x 0.8 + 0.6 Relative wall thickness was calculated using the formula.

RWT = IVSD + LVPWD / LVIDD 3.9 Echocardiographic Terms:

The standard values used for the various components; and the various patterns was interpreted according to standard definition⁸⁷

1 LV systolic dysfunction^: Fractional shortening < 25%, Ejection fraction < 50%.

lxv 2. LV diastolic dysfunction^:

Stage 1 - E: A ratio ≤ 0.75 and deceleration time (DT) > 220msec.

Stage 2 (pseudo-normal) - E: A ratio 0.75-1.5 and DT 150-200msec.

Stage 3 - E: A ratio ≥ 1.5 and DT < 140msec 3. LV remodeling pattern classified as⁸⁷

-Normal geometry when there is normal LVMI and normal RWT (≤0.5).

-Concentric remodelling when there is normal LVMI and RWT ≥ 0.5.

-Eccentric left ventricular hypertrophy when there is increased LVMI and normal RWT.

-Concentric left ventricular hypertrophy when there is increased LVMI and increased RWT.

-Normal LVMI : < 131g/m² ( men); <100g/m² (women) 3.10 Preparation for data collection

Consent was also obtained from the Consultant Hematologist in charge of the adult sickle cell disease clinic of JUTH.

3.11 Data analysis

Data was analyzed using the EPI- Info version 3.5.3 (CDC Atlanta, Georgia USA) statistical software. Quantitative variables were summarized using mean and standard deviation (SD).

Categorical variables were expressed using percentages. The student t –test was used to compare means of 2 groups (Patients with HbSS and controls).

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The Chi Square (X²) test was used to test the significance of association between categorical variables. Where the expected frequency of a cell was <5, Fisher’s exact test was used.

Variables that had a p-value of <0.05 on univariate analysis were entered into a multiple logistic regression model to determine their independent association with prevalence of left ventricular dysfunction in sickle cell anemia patients. In all cases, p- value of <0.05 was considered statistically significant.