CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 3, April 2013
AFRICA
73
Left ventricular systolic function, end-diastolic dimension
and wall thickness were measured by means of standard
M-mode and two-dimensional views. Using previously published
normal values,
z
-scores were calculated.
11,12
Mitral and aortic
regurgitation were classified according to width and length of
colour Doppler jet as mild (jet
<
25%), moderate (jet 25–50%)
or severe (jet
>
50%).
Approval by the local medical ethics committee was obtained.
Data were analysed using standard statistical software (SPSS
for windows
®
, Chicago, Illinois, USA, version 18). Data are
presented as medians with minimum and maximum values
where appropriate.
Results
The median age at presentation was 8.5 days (range: 6.0–11.0)
with a median body weight of 3.58 kg (range: 0.86–4.70). All
infants were full term, except one 28 weeks premature infant
with a birth weight of 860 g. All patients had circulatory
failure and required admission to the intensive care unit for
cardiopulmonary support. At initial presentation, three infants
had hypertension while two patients were hypotensive and one
normotensive. Hypertension in the latter only became evident
after resuscitation and restoration of cardiac output. Common
symptoms included lethargy, feeding intolerance or poor feeding.
Patient characteristics are depicted in Table 1.
Umbilical arterial lines had been inserted in two children
prior to the episodes of hypertension. None of the mothers were
diabetic and maternal health was good except in one where a
history of herpes infection and pre-eclampsia was present. There
was no history of ingestion of drugs associated with hypertension.
Lactate levels were elevated in most infants on admission
(Table 1), with a median of 2.6 mmol/l (range: 1.4–11). Troponin
levels were measured in three patients and were elevated in
patients 1 and 5: 0.16 and 2.01
µ
g/l, respectively (normal:
<
0.13
µ
g/l). Both plasma renin activity (PRA) and aldosterone levels
were markedly elevated in five patients, with medians of 32.6
µ
g/l/h (range 10.5–
>
37) (local laboratory neonatal reference
value:
<
16.6
µ
g/l/h) and 2 396 ng/l (range: 763–24 920) (local
laboratory neonatal reference value: 7–184), respectively. In one
patient aldosterone levels were within the normal range, but PRA
was elevated (37.4
µ
g/l/h). Urine catecholamines were normal
in all patients. Plasma PRA and aldosterone levels gradually
decreased and normalised in all patients after a median of eight
days (range: 7–13) and antihypertensive treatment could be
diminished or discontinued.
Systolic cardiac function was considerably impaired in
three patients and mildly impaired in two, with a median SF
of 25% for the group as a whole (range: 10–30%, Table 1),
while left ventricular end-diastolic dimensions were within
normal reference ranges (Table 2). Left ventricular posterior
wall thickness was increased in three and interventricular septal
thickness in four patients, respectively (Table 2).
In one patient with considerable hypocontractility, a thrombus
of 5
×
9 mm was observed in the apex of the left ventricle (Fig.
1). Mild to moderate aortic regurgitation was seen in five of the
six patients (Fig. 2) and mild to moderate mitral regurgitation
(MR) in all (Table 1). All aortic and mitral valves were
morphologically normal. Interestingly, the coronary arteries
were reported to be more prominent than usual in four patients
on visual inspection of the echocardiograms (Fig. 3).
Milrinone was used in five patients to treat circulatory
failure. All patients improved rapidly with normalisation of left
ventricular systolic function. The majority of patients required at
least two antihypertensive drugs to control the blood pressure in
the intensive care unit once they were stabilised.
Underlying causes of hypertension were found in three
patients. One patient had a vascular insult of the right kidney
and one a dysplastic right kidney. Thrombosis of the abdominal
aorta was seen in the 860-g neonate who did not survive. Both
this patient as well as the infant with vascular damage of the
kidney had umbilical arterial lines prior to presentation. No
demonstrable underlying cause could be identified in the other
three patients.
TABLE 1. CLINICAL CHARACTERISTICSAT PRESENTATION
Echocardiography
Anti-HT
Rx follow
up
Weight
(g)
BP
(mmHg)
Lactate
(mmol/l) Associated symptoms
Central line
Regurgi-
tation SF % Findings
1 3210 –
2.5
shock, respiratory distress
–
AR, MR 10 –
yes
2 4700 160/110 1.4
RF
umbillical, venous
AR, MR 30 –
no
3 3650 –
3.2
shock
umbillical, arterial and venous AR, MR 17 vascular insult right kidney no
4 3520 140/110 2
feeding intolerance, electro-
lyte disturbances
femoral, venous
MR 25 –
no
5 3680 100/70 11
distended abdomen
femoral, venous
AR, MR 25 dysplastic right kidney
yes
6 860 –
1.7
poor circulation
umbillical, arterial and venous AR, MR poor* thrombus occlusion
descending aorta
died
BP: blood pressure at initial presentation, SF: shortening fraction at initial presentation, R: respiratory failure, AR: aortic regurgitation, MR: mitral regurgi-
tation, R: right, anti-HT Rx: antihypertensive medication.
*Extremely poor contractility on visual inspection, measurements not possible (initial echocardiogram).
TABLE 2. ECHOCARDIOGRAPHIC FINDINGS
LVEDD IVS
LVPW
Measurement (mm)
median
19
5
5
minimum
16
4
4
maximum
21
10
5
z
-score
median
1.1
4.2
2.5
minimum
–0.6
0.8
0.2
maximum
2
5.9
2.5
LVEDD: left ventricular end-diastolic diameter, IVS: interventricular
septum, LVPW: left ventricular posterior wall.
