Page 751 - ACCCN's Critical Care Nursing

728 S P E C I A LT Y P R A C T I C E I N C R I T I C A L C A R E

the cardiovascular system in pregnancy is poorly tolerated Treatment Priorities
by some women and cardiac disease in pregnancy remains All women with cardiac disease are considered to have a
a leading cause of death in Australia. 52
‘high risk’ pregnancy and should receive maternity care
Rheumatic heart disease is the most frequently acquired by a multidisciplinary team including as a minimum,
151
heart disease and is a condition normally associated with obstetrician, midwife, cardiologist and anaesthetist.
developing countries. 144 In Australia, rheumatic heart The timing and location of delivery, choice of anaesthesia
disease is a significant concern in Aboriginals and Torres and delivery mode should each be discussed by the team
Strait Islanders with rates in Indigenous communities in with the woman, and planned well in advance. If a preg-
the Northern Territory noted to be the highest in the nant woman with cardiac disease is admitted to ICU, this
world, and are over 30 times higher than non-Indigenous multidisciplinary team should be consulted about her
¯
Australians. 145,146 Similarly in New Zealand, Maori and care. Priorities of care include:
Pacific Islanders have a much higher incidence of rheu- l Pre-pregnancy counselling: this should allow a full
matic heart disease than New Zealanders of European and frank discussion about the likely risks of preg-
ancestry. Refugee and immigrant women who have nancy for the individual and to discuss a treatment
migrated from developing countries also have a higher path. This is of particular importance for women
risk for rheumatic heart disease in pregnancy. Rheumatic who are on potentially teratogenic medication, such
heart disease is a delayed complication of acute rheu- as warfarin, and for women who may benefit from
matic fever, and results from untreated Group A strepto- surgery or interventional treatment prior to conceiv-
coccus bacterial infection. It most commonly affects the ing. Additionally, women with congenital heart disease
mitral valve, though may also affect the aortic valve and may require genetic counselling to determine the like-
usually involves restricted leaflet mobility, focal or lihood of congenital heart disease in any offspring.
generalised valvular thickening and abnormal subvalvu- l Diagnosis: standard investigations including chest
lar thickening, resulting in regurgitation and, rarely, X-ray, ECG, CT scan and MRI should be attended to
stenosis. 147
as indicated by the clinical condition. In general, diag-
A cardiac condition increasingly presenting in pregnancy nostic imaging of a critically ill woman should not be
is acute myocardial infarction (AMI), thought to be withheld due to concerns about the fetus, with
related to the changing demographics of the pregnant abdominal shielding used whenever possible. 152
population, such as older women becoming pregnant. 148 l Heart failure: as was outlined in the section on peri-
AMI is the leading cardiac cause of maternal death in the partum cardiomyopathy, the principles of treatment
UK, mostly related to undiagnosed ischaemic heart for heart failure in pregnancy are the same as for the
24
disease. Additionally, spontaneous aortic dissection and non-pregnant population.
coronary artery dissection may also occur in pregnant l Arrhythmias: commonly used drugs including digoxin,
women with no preexisting disease. 149 Signs and symp- lignocaine, flecainide, verapamil, sotalol, propranolol,
toms of heart failure and complaints of chest pain must adenosine and amiodarone; although limited studies
be investigated and not put down to the ‘minor discom- exist in the pregnant population, all have been used
forts’ of pregnancy, such as breathlessness, heartburn, safely and effectively during pregnancy. 153 Transient
fatigue and dependent oedema. Given that the cardiac neonatal hypothyroidism has been described in
output is expected to increase 40–50% in a normal preg- women on amiodarone and monitoring of neonatal
nancy, any cardiac condition resulting in poor left ventric- thyroid function is recommended. 154
ular function and/or restricted left ventricular outflow are l Cardiac surgery: interventions such as valvuloplasty
particularly associated with poor outcomes in pregnancy. may be required. Open-heart surgery is only per-
formed during pregnancy when the maternal condi-
Also relevant for the outcome of both mother and baby tion is critical, for example coronary artery dissection
is whether any valvular disease has been repaired and or severe dysfunctioning valve, because of the high
whether a tissue or mechanical valve has been inserted. chance of fetal loss associated with the woman going
Use of anticoagulants is of particular concern during on bypass. Standard care should be provided to a
pregnancy, with warfarin contraindicated for use in preg- pregnant woman, with care to nurse the woman
nancy. However, the risk of thrombosis is relatively high ≥20 weeks’ gestation with a 15 degree left lateral tilt
in pregnant women and some women remain on warfa- if possible, to reduce the negative effects of aorto-caval
rin despite the risk of associated congenital anomaly and compression. Open-heart surgery and ECMO have
the increased likelihood of miscarriage. 150
been used successfully in pregnant women with good
outcomes for mother and baby. 155,156
l Thrombus prevention: this is a priority in women with
Practice tip valvular disease/prosthetic valves, atrial fibrillation or
dilated heart chambers at risk of thrombus formation,
Congenital and acquired cardiac disease can present for the especially because of the normal hypercoagulopathy
first time during pregnancy, unmasked by the additional associated with pregnancy. Warfarin embryopathy, a
phy siological requirements of pregnancy. Women with known recognised collection of developmental anomalies
preexisting disease may experience unpredictable deteriora- such as nasal hypoplasia and epiphysis stippling, is
tion in cardiac function. associated with warfarin use in the first trimester, con-
sequently warfarin use is contraindicated. However,