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.