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COMMENTARY Detecting heart defects in newborn infants / innocent murmurs mixed with silent dangers MIKAEL NORMAN Karolinska University Hospital, Stockholm, Sweden Abstract Detection of severe heart defects without unnecessary delay is a primary task for providers of infant care. Screening is challenged by the fact that a normal physical examination after birth does not exclude severe defects. Shorter hospital stay for newborn infants and a reduced number of examinations may further hamper a successful mission. Reassuringly, most critical heart defects are reported to be identified early. Conclusion: Increased awareness of the limitations of screening and continued monitoring of detection 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 Sunnega ˚rdh [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: [email protected] Commentary on ‘Failure to diagnose critical heart malformations in newborn infants before discharge / an increasing problem?’ by Mats Mellander and Jan Sunnega ˚rdh Acta Pædiatrica, 2006; 95: 391 /393

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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:

[email protected]

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

[1] Richmond S, Wren C. Early diagnosis of congenital heart

disease. Semin Neonatol 2001;/6:/27�/35.

[2] Brown S, Small R, Faber B, Krastev A, Davis P. Early postnatal

discharge from hospital for healthy mothers and term infants

(Cochrane Review). In: The Cochrane Library, Issue 2.

Chichester, UK: John Wiley & Sons, Ltd, 2004.

[3] Glazener CM, Ramsay CR, Campbell MK, Booth P, Duffty P,

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

(NEST): a randomised, controlled, switchback trial of alter-

native policies for low risk infants. Br Med J 1999;/318:/627�/32.

[4] Townsend J, Wolke D, Hayes J, Dave S, Rogers C, Bloomfield

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[5] Mellander M and Sunnegardh J. Failure to diagnose critical

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Commentary 393