CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 1, January/February 2013
AFRICA
195
domain and frequency domain. Mean heart rate, P wave, P dispersion
(Pd), QT, QTc, QTd and QTcd intervals were measured from electro-
cardiogram on admission and at discharge.
Results:
Time-domain indices (SDNN, SDANN, rMSSD, SDNN
index and NN50) were similar between patient and control groups (
p
>
0.05). Among the frequency-domain indices, mean HF level in the
CO poisoning group was higher than in the controls (
p
=
0.018) while
LF levels were similar (
p
=
0.636). LF/HF ratio was significantly
lower in the CO poisoning group (
p
<
0.001). CoHb levels were nega-
tively correlated with LF/HF ratio (r
=
-0.351,
p
<
0.05). On admis-
sion, mean heart rate, QTd, QTcd, and Pd values were higher in the
CO poisoning group (
p
<
0.05). On discharge, QTd and QTcd were
still longer in the CO poisoning group than in the controls (
p
<
0.05).
Conclusions:
Frequency-domain indices recorded within the first
five minutes on admission, especially the LF/HF ratio, are useful
for evaluating cardiac autonomic function. Decreased LF/HF ratio
reflects a balance of autonomic nervous system which shifted to
parasympathetic components. These results suggest that exposure to
CO may alter the balance of cardiac autonomic control, and thus may
increase the susceptibility of high-risk patients to adverse cardiac
events.
870: DOES MEASURMENT OF OXYGEN SATURATION
IMPROVE THE DIAGNOSTIC DETECTION OF CONGENI-
TAL HEART DISEASE DURING POPULATION SCREEN-
ING?
Minnette Son
1
, Cathy Woodward
1
, Kirk Milhoan
2
, David Bush
1
1
University of Texas Health Science Centre, San Antonio, USA
2
Hearts and Souls, San Antonio, USA
Background
: No consensus exists regarding the most efficient means
to conduct population-based screening of children for undiagnosed
congenital heart disease (CHD). A similar lack of consensus exists
in the USA regarding the benefit of screening oxygenation saturation
(O
2
Sat) prior to newborn discharge. We sought to determine whether
assessing O
2
Sat would increase the sensitivity of CHD diagnosis
during humanitarian, population-based paediatric screening.
Methods
: During a humanitarian screening in two rural provinces in
Mongolia (Mandal Gobi and Dalanzagdad), children from one month
to 20 years underwent a cardiac physical examination by American
and Mongolian paediatricians and nurse practitioners. All children
also underwent evaluation of oxygen saturation with pulse oximetry.
A potentially pathological murmurs on examination or oxygen satu-
rations less than 94% prompted echocardiographic screening (echo)
by a paediatric cardiologist.
Results
:
Previously unrepaired CHD was identified in 61 of 822
patients (7.0%) screened over four days, with 133 echos performed
(16.1%). Identified cardiac defects included: 19 haemodynamically
insignificant ventricular septal defects (VSDs), nine haemodynami-
cally significant VSDs, 10 patent ductus arteriosi, eight atrial septal
defects and two tetralogy of Fallot (ToF) patients. Remaining lesions
were only minor valve abnormalities; 49 patients (6%) had O
2
Sat
<
94% on screening. Of these patients, seven had CHD (sensitivity for
pulse oximetry to diagnose CHD
=
11.5%). A reading
≥
94% carried
a higher specificity and negative predictive value (94.5 and 93%,
respectively). Only one patient had oxygen saturation
<
94% with a
negative auscultatory examination (child with ToF and O
2
Sat 72%).
Of the 42 patients without CHD and O
2
Sat
<
94%, all had normal
examinations.
Conclusions
: While specificity is high, O
2
Sat appears to have suffi-
ciently low sensitivity and adds little to the diagnostic accuracy of
physical examination alone, to warrant its use as a tool for popula-
tion-based screening of paediatric patients.
873: EFFECTIVENESS OF INDOMETHACIN IN FULL-
TERM INFANTS WITH SYMPTOMATIC PATENT DUCTUS
ARTERIOSUS
Young Earl Choi, Young Kuk Cho, Hwa Jin Cho, Jae Sook Ma
Department of Paediatrics, Chonnam National University Medical
School and Hospital, South Korea
Background:
Common treatment methods for patent ductus arte-
riosus (PDA) include surgical ligation and, recently, catheter inter-
vention. Inhibiting prostaglandin synthesis seems effective for the
non-surgical closure of PDA and indomethacin has been widely used
with a reported efficacy of 70–80% in preterm neonates with signifi-
cant PDA. However, there is a controversy on the effectiveness of
indomethacin in full-term neonates with significant PDA. Therefore
we evaluated the effect on indomethacin treatment on patients with
significant PDA among full-term infants with birth weight (BW)
≥
2
500 g and a gestational age (GA)
≥
37 weeks.
Methods:
We retrospectively reviewed 29 infants with significant
PDA and a BW of 2 500 g or more and a GA of 37 weeks or more who
were admitted to Chonnam National University Hospital between
2007 and 2009. During indomethacin therapy, feeding was prohibited
and water intake restricted (60–80 ml/kg/day). Indomethacin (0.25
mg/kg/day) was intravenously administrated as a single dose at 12- to
24-hour intervals. Patients were classified as responders if there was
complete closure of the DA and as partial responders if there was
incomplete closure of the DA and clinical symptoms improved. The
remaining patients were classified as non-responders.
Results:
In indomethacin-treated patients, 13 (44.8%, responders) of
29 patients with PDA were completely closed. Eight (27.6% partial
responder) were incompletely closed but clinical symptoms such as
congestive heart failure improved without any particular treatment.
Conclusions:
Indomethacin therapy may be a useful medical treat-
ment option prior to considering surgery for PDA in full-term infants.
874: RHEUMATIC HEART DISEASE IN NAMIBIA: A
PRELIMINARY REPORT FROMTHE NATIONAL REGISTRY
C Hugo-Hamman, M. Kaaya, H du Toit, A Willberg, S Nzuza, M
Awases
Windhoek Central Hospital, Ministry of Health and Social Services,
Republic of Namibia
Background:
The burden of rheumatic heart disease (RHD) in
Namibia is unknown and there is no epidemiological data with which
to inform public policy. The aim of this registry was to collect data
to assist resource development and distribution with the end objec-
tive a reduction in prevalence, morbidity and mortality rates from a
much-neglected disease.
Methods:
This was a prospective, national, hospital-based registry
of patients referred to the RHD Clinic at Windhoek Central Hospital.
Questionnaires documented patients’ presentation, clinical course,
investigations, complications, management and demographics at
enrollment. The study was initiated in July 2010 in collaboration with
the Global Registry for RHD (REMEDY).
Results:
One hundred and ninety-three patients were enrolled, with
the distribution of cases reflecting regional population density; 58%
were male and 42% female, 81% between 10 and 40 years and 5%
under 10 years. Thirty-two per cent had severe disease (NYHA
III–IV). The mitral valve was most commonly affected (77% with
MR, 40% with MS), followed by tricuspid then aortic valve disease.
Nineteen per cent hade atrial fibrillation, 6% stroke and 13% previ-
ous surgery; 38% of patients are receiving secondary penicillin
prophylaxis. Of those needing anticoagulation, 44.7% were receiving
warfarin and of those, 38% were aware of the target INR; 73% had
no INR analysis in the preceding six months.
Conclusion:
Patients are referred late with advanced disease. The
low number of patients on secondary prophylaxis reflects a lack
of awareness of the disease among the general public and health
workers. Poor compliance with anticoagulation protocols indicates
health workers are poorly informed about heart disease and reflects
weakness in organisation of laboratory services. The RHD burden
is highly significant. Gaps have been identified in the organisa-
tion and delivery of care and point to the urgent need for a national
programme for the prevention and control of rheumatic heart disease.
