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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 1, January/February 2019
AFRICA
5
Cardiovascular Topics
A retrospective review of right-sided hearts at a South
African tertiary hospital
Nadia Beringer, Antoinette Cilliers
Abstract
Background:
A right-sided heart (RSH) has three main
causes: dextrocardia, dextroposition and dextroversion. It
may be associated with cardiac malformation, extra-cardiac
abnormalities and adverse patient outcomes. The aim of
this study was to determine the prevalence, demographics,
associated cardiac malformations (ACM) and outcome of
paediatric patients diagnosed with a RSH at a South African
tertiary hospital.
Methods:
A retrospective review was performed over a
22-year period.
Results:
RSH comprised 1% of the paediatric cardiology
referrals. Dextrocardia was the most frequent cause (58.1%)
and the majority of these patients had ACM (81.5%). More
than a third (40.9%) were diagnosed with dextroposition,
secondary to extra-cardiac factors. Dextroversion was the
least common cause (1.1%). Over a quarter of all patients
were confirmed dead at the time of the study; most had been
diagnosed with dextrocardia. Two-thirds of the patients were
lost to follow up.
Conclusion:
A RSH is an unusual occurrence. Dextrocardia,
the most common cause, is frequently associated with ACM
and extra-cardiac abnormalities. It is therefore important to
timeously elucidate the cause of a RSH.
Keywords:
right-sided hearts, dextrocardia, dextroposition,
dextroversion
Submitted 25/5/17, accepted 22/10/18
Published online 21/11/18
Cardiovasc J Afr
2019;
30
: 5–8
www.cvja.co.zaDOI: 10.5830/CVJA-2018-051
A right-sided heart (RSH) is a cardiac malposition that is
predominantly caused by dextrocardia, dextroversion or
dextroposition. Each cause has a different aetiology, associated
cardiac malformations (ACM) and outcome.
1
ACM range from
severe cyanotic congenital heart defects to sub-clinical ductal
lesions
2
Dextrocardia is the most common cause of a RSH. The
reported incidence ranges from 0.01% of all live births in high-
income countries
2,3
to a slightly higher incidence of 0.35% in
low-income countries.
4,5
It occurs when the base–apex of the
heart is displaced to the right.
3,4
Factors intrinsic to the heart are
responsible for this malformation, which occurs during foetal
embryogenesis. However, no specific genetic cause or inheritance
pattern for dextrocardia has been identified.
6
Dextrocardia is
often accompanied by ACM.
3,7
Dextroposition is the displacement of the heart to the right
hemi-thorax, secondary to extra-cardiac causes.
1
It is not usually
associated with ACM.
1,7,8
Dextroversion results from a congenital malrotation of the
ventricular part of the heart about its long axis with the atria
remaining in the normal position.
1
It is essentially dextrocardia
with normally related atria and viscera.
4
ACM are very common
and mostly involve the cono-truncal region of the heart.
1
The term situs is not only used to describe the atrial position,
but also the anatomical position of the abdominal and thoracic
organs.
9,10
There are three types of situs described associated
with a RSH: situs solitus, situs inversus and situs ambiguous.
9-11
Situs solitus refers to the normal position of the atria, thoracic
and abdominal organs.
3,10
The complete mirror image of this
relationship is situs inversus.
10
When situs cannot be determined anatomically, it is referred
to as situs ambiguous.
3,10
This is also known as heterotaxy or
isomerism and is invariably coupled with severe cardiac and
non-cardiac malformations. Situs ambiguous is further divided
into right atrial isomerism (RAI) and left atrial isomerism
(LAI).
3,7,10
Non-cardiac malformations include: asplenia in RAI
and polysplenia and biliary atresia in LAI. Malrotation of the
gut can occur in both.
11,12
The incidence and severity of complex cardiac anomalies
are directly proportional to the failure of shift of the cardiac
apex with regard to the abdominal and thoracic organs. In
other words, situs solitus dextrocardia is more likely to be
associated with cardiac malformations, compared to situs
inversus dextrocardia.
10,13,14
Failure to diagnose a RSH and its associations may impact
on patient outcomes. To date, there are no publications from
the African continent describing RSH: its overall prevalence,
Charlotte Maxeke Johannesburg Academic Hospital,
Johannesburg, South Africa
Nadia Beringer, MB ChB, MMed, DCH, FCPaed, nadia.beringer@
gmail.comFaculty of Health Sciences, University of the
Witwatersrand, Johannesburg; Paediatric Cardiology
Division, Department of Paediatrics and Child Health, Chris
Hani Baragwanath Academic Hospital, Johannesburg,
South Africa
Antoinette Cilliers, MB BCh, DCH (SA), FCPaed (SA)