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COMMENTARY
Detecting heart defects in newborn infants �/ innocent murmurs mixedwith silent dangers
MIKAEL NORMAN
Karolinska University Hospital, Stockholm, Sweden
AbstractDetection of severe heart defects without unnecessary delay is a primary task for providers of infantcare. Screening is challenged by the fact that a normal physical examination after birth does notexclude severe defects. Shorter hospital stay for newborn infants and a reduced number ofexaminations may further hamper a successful mission. Reassuringly, most critical heart defects arereported to be identified early.
Conclusion: Increased awareness of the limitations of screening and continued monitoring ofdetection rates, as well as studies on how they can be improved, are warranted.
Key Words: Congenital heart defect, newborn infant, screening, diagnostic accuracy
An important aim for the routine physical examina-
tion of newborn infants is detection of congenital
heart defects. In severe heart defects, early diagnosis
can be life saving and reduce long-term morbidity.
Both professionals and parents may consider heart
auscultation as an effective and simple screening test.
However, critical heart defects are often clinically
silent and easily missed at neonatal examination,
whereas innocent murmurs are common [1]. The
situation is complicated by demands for a more
effective organisation of normal neonatal care. Driven
by cost reductions, but also encouraged by many
caretakers and parents, early discharge from hospital
has become the rule in several countries. The number
of routine examinations has decreased and in many
hospitals, a majority of newborn infants are examined
only once before discharge to home. Although Co-
chrane reviews and randomized clinical trials are
reassuring as regards overall safety in early discharge
of low risk babies after a single routine examination
[2�/4], concerns about missed diagnosis of heart
defects have been raised.
In this context, the report by Mellander and
Sunnegardh [5] published in this issue of Acta
Paediatrica is important. They studied detection rates
of critical heart defects in a large population-based
cohort of 351 843 births in Sweden. Among live-born
term infants, 0.9/1000 was found to have a critical
heart defects in need of live-saving surgical or catheter
intervention before 2 months of age. A clear majority
(80%) of these infants with a critical heart defect
(total n�/259) was diagnosed before discharge from
hospital. The remaining 20% left the delivery or
maternity wards undiagnosed, mainly infants with
obstructive left heart malformations with duct-de-
pending systemic circulation (co-arctation of the
aorta, interrupted aortic arch and hypoplastic left
heart syndrome). The long-term morbidity and
mortality from critical heart defects were not signifi-
cantly higher among infants discharged undiagnosed
compared to those diagnosed before discharge.
During the 8-year study period �/ between 1993 and
2001 �/ the proportion undiagnosed before hospital
discharge increased. In the same period, early dis-
(Received 13 November 2005; accepted 18 November 2005)
ISSN 0803-5253 print/ISSN 1651-2227 online # 2006 Taylor & Francis
DOI: 10.1080/08035250500482289
Correspondence: Mikael Norman, Neonatal Unit K76-K78, Karolinska University Hospital, Huddinge, 141 86 Stockholm, Sweden. E-mail:
Commentary on ‘Failure to diagnose critical heart malformations in newborn infants before discharge �/ an increasing problem?’ by Mats Mellander and Jan
Sunnegardh
Acta Pædiatrica, 2006; 95: 391�/393
charge from hospital (before 72 h of postnatal age)
increased from 30 to 60%. The authors conclude that
many infants with critical heart defects are not
diagnosed before discharge from hospital, that the
proportion of overlooked defects has increased and
that neonatal screening fails.
The difficulties and limitations in diagnosing
congenital cardiac defects in the neonatal period
are not unknown. However, the question is how
widespread this knowledge is. Reviewing the litera-
ture, Richmond and Wren found several studies
with neonatal detection rates of cardiac defects
below 50% [1]. In view of these findings, the high
predischarge detection rate reported this week is
encouraging, particularly as it was restricted to the
most severe heart defects. Even in the most difficult
group to diagnose �/ i.e. left ventricular outflow
tract obstructions �/ 70% of the infants had been
detected before hospital discharge. In comparison,
these are high numbers [6].
An important goal of postpartum care is to
promote health and well-being and to avoid un-
necessary medical interference between a mother
and her infant. In this sense, early discharge from
hospital may well be appropriate. Before early
discharge, however, detectable abnormalities must
be excluded by physical examination of the baby.
The mother’s knowledge, ability and confidence in
providing adequate care for her infant must also be
considered. Finally, a follow-up visit should be
scheduled [7]. Between 1993 and 2001, Mellander
and Sunnegardh found an increasing proportion of
undiagnosed critical heart defects before hospital
discharge [5]. This finding may have different
explanations and implications. First, it could signal
delayed detection after early discharge. However,
this cannot be the only reason because the majority
of infants with critical heart defects who passed
undiagnosed stayed longer in hospital than 72 h
after birth. Another explanation could be an in-
creasing ignorance and/or inappropriate action in
babies who did present symptoms and signs upon
examination, irrespective of their length of hospital
stay (LOS). In times of ‘drive-through’ deliveries
with high expectations of normality, lapses in
diagnosis and management of different neonatal
conditions can occur, both at the birth site and
post discharge [8]. Finally, the proportion of post-
discharge diagnoses would be expected to increase
just by shortening the LOS, even in the absence of
an actual change in postnatal age at diagnosis.
Provided follow-up was organized and carried out,
networks in the primary health care system func-
tioned and parents had been informed what to look
for, the diagnosis of critical heart defects may not
have been significantly delayed. The fact that more
than 90% of interrupted aortic arches (n�/14) and
hypoplastic left heart syndromes (n�/51) were
diagnosed within 6 days after birth supports such
an interpretation.
In conclusion, detecting critical heart defects in
the newborn is difficult. A normal routine examina-
tion at birth does not exclude serious cardiac
malformations Figure 1. Every second infant born
with co-arctation of the aorta (a condition that
rapidly can become life threatening) passed unde-
tected at the first neonatal examination and he or
she was discharged home without a diagnosis. This
is important knowledge in order to provide safe and
appropriate practices in neonatal care, irrespective
of the length of hospital stay. Although a majority of
critical heart defects were shown to be identified
early, continued monitoring of detection rates and
studies on how they can be improved are warranted.
Providing guidelines and education on these issues
are equally important.
References
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Lloyd DJ, et al. Neonatal examination and screening trial
Figure 1. A critical heart defect cannot be excluded by routine
examination of the newborn infant (whereas jaundice can).
392 Commentary
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Commentary 393