Abstract –
Spontaneous coronary artery dissection (SCAD) is a rare phenomenon which
occurs predominantly in the immediate postpartum period in young women.
A SCAD whilst pregnant is very rare and poses significant risk to the
mother and unborn child, and with minimal data on SCAD antenatally, the
obstetric dilemma of timing and mode of delivery is not clear. This case
of a 33 year old nulliparous woman with a SCAD at 33 weeks gestation
focuses on the diagnostic and delivery implications from a cardiology,
anaesthetic and obstetric point of view. Given its rarity, this case
aims to increase the database of SCAD in pregnancy to provide practice
points in delivery.
Authors
Thomas Paxton-Hall, Gold Coast University Hospital, Email:
paxtonhall.thomas@gmail.com
Pranali Desai, Mater Mothers Hospital, Email:
pranalidesai87@gmail.com
Nicholas Seton, Gold Coast University Hospital, Email:
nick.seton@health.qld.gov.au
Chris Arthur, Gold Coast University Hospital, Griffith University,
Email:
chris.arthur@health.qld.gov.au
Background
Cardiovascular disease is present in 1-4% of pregnancies and is
escalating which is considered to be as a result of factors such as
advancing maternal age and increasing rate of pregnancy risk factors
such as diabetes mellitus, pre-eclampsia and multiple gestation
pregnancies. Medical advances have resulted in more women with
congenital cardiac conditions surviving until, and well past,
childbearing age. The relative change in cardiac output and blood volume
in pregnancy can alter haemodynamic properties antenatally, intrapartum
and postpartum. Whilst there has been research and development of risk
stratification for pregnant women with known cardiac conditions such as
valvulopathies and cardiomyopathies, evidence for conditions with
intrapartum onset is less established1,2.
The incidence of spontaneous coronary artery dissection (SCAD) in
pregnancy is a rare phenomenon with management considerations that
differ to SCAD in the non-pregnant state or similar. It can be a
life-threatening condition which poses delivery considerations if it
occurs antenatally. This case report describes a particularly rare case
of SCAD in the late pre-term period, in contrast to the immediate
post-partum period as is most commonly seen.
Case
A 33-year-old nulliparous woman presented to a regional emergency
department at 33 weeks’ gestation describing subacute chest pain,
diaphoresis and dyspnoea. The pregnancy was a spontaneous conception and
the antenatal period had only been complicated by iron deficiency for
which the patient was taking oral iron supplements. Her combined first
trimester screen and non-invasive prenatal test (NIPT) were low risk,
and in addition she had a normal morphology ultrasound at 20 weeks
gestation. Her medical history consisted of recurrent spontaneous
pneumothoracies of the left lung in childhood, with the left lung having
undergone a pleurodesis. She denied smoking or alcohol use, though
admits to historical recreational cocaine use, however not in the years
immediately prior to or during this pregnancy. There was no familial
history of cardiac medical conditions.
On presentation to the regional emergency department, she described
acute onset, central, dull chest pain with radiation to both axilla, and
associated nausea and diaphoresis. This was on the background of two
weeks of worsening gastro-oesophageal reflux symptoms. There was no
associated paraesthesia, pleurisy or palpitations. The initial workup in
the regional emergency department included a chest X-ray and point of
care transthoracic echocardiogram (TTE), both of which were normal. An
electrocardiogram (ECG) showed equivocal T-wave inversion in Lead III.
However, a point of care cardiac troponin went from 0.00ug/L to 0.54ug/L
in eight hours (ref: 0.00-0.04ug/L). Given the positive troponin and
pregnancy status, she was transferred by road to a tertiary obstetric
centre. On arrival, a formal troponin was obtained at a level of
4829ng/L (<10ng/L normal). Throughout the event, her
observations remained within normal limits. She was admitted for
telemetry monitoring in the Cardiac Care Unit (CCU) and was reviewed by
the on call obstetric team. After counselling and before further
investigation, two doses of 11.4mg intramuscular betamethasone were
administered (with a 24-hour interval) and she was commenced on
therapeutic enoxaparin at 1mg/kg/day.
Further investigations were conducted including femoral and carotid
doppler studies, autoimmune screening, serial ECG’s and a formal TTE
showing a left ventricular ejection fraction of 68%; all were within
normal limits. A computerised tomography pulmonary angiogram (CTPA) and
an angiogram of the heart were considered however, both were abandoned
due to the risks of iatrogenic artery dissection and radiation to the
fetus. In the absence of an angiogram but with the available results
from investigations to date, a spontaneous coronary artery dissection
(SCAD) was diagnosed clinically.
Figure 1 : ECG on admission.