Cardiac disease in pregnancy Flashcards
Define
Define
Cardiomyopathies – includes peripartum cardiomyopathy (new-onset cardiomyopathy and heart failure usually within the last month of pregnancy to 5 months post-partum)
· Pathophysiology – 40% rise in blood volume during pregnancy causing strain and women with cardiac disease cannot increase CO leading to uterine hypoperfusion and increased pulmonary oedema
· Epidemiology = increasing due to increased maternal age, increased life expectancy and increased immigrant populations
Symptoms
Classify based on the NYHA classification [see diagram with signs and symptoms)
- Most women will remain well throughout pregnancy; normal cardiac responses:
- ESM in 96% (more CO) Forceful apex (more CO)
- 3rd heart sound in 84% (more cardiac volume) Peripheral oedema (more volume)
Investigations
echocardiogram is usually performed at booking and at 28 weeks
Management
Anticoagulation is essential in patients with congenital heart disease who have pulmonary hypertension or artificial valves and those at risk of AF (WARNING: warfarin is teratogenic if used in the first trimester)
- LMWH is used as an alternative to warfarin
High Risk Cardiac Conditions
- Systemic ventricular dysfunction
- Pulmonary hypertension
- Cyanotic congenital heart disease
- Aortic pathology (e.g. Marfan’s syndrome)
- Ischaemic heart disease
- Left heart obstructive lesions (e.g. aortic/mitral stenosis)
- Prosthetic heart valves
- Previous peripartum cardiomyopathy
- Foetal Risks of Maternal Cardiac Disease
- Recurrence (congenital heart disease) Maternal cyanosis (foetal hypoxia)
- Iatrogenic prematurity FGR
- Effects of maternal drugs (teratogenesis, growth restriction, foetal loss)
Management of Labour and Delivery
- In most cases, aim to wait for spontaneous labour
- 2nd stage kept short with elective forceps or ventouse delivery à reduces maternal effort and need for an increased cardiac output (c-section for those where any effort is dangerous)
- Ergometrine may be dangerous (causes vasoconstriction, hypertension and heart failure) so active management of the third stage is with syntocinon ALONE
- Syntocinon is a vasodilator so introduce it slowly
- Induction may be considered in very high-risk women to ensure that delivery occurs at a predictable time with all the personnel present
· Epidural anaesthesia is usually recommended to reduce pain-related stress
· Risk of maternal hypotension
- Prophylactic antibiotics should be given to any woman with a structural heart defect
· Reduce the risk of bacterial endocarditis
- Postpartum haemorrhage is dangerous because it can lead to cardiovascular instability
Summary
Echocardiogram at booking and at 28 weeks
o Anticoagulation may be necessary
o Avoid induction of labour if possible
o Use prophylactic antibiotics
o Ensure fluid balance
o Avoid supine position
o Discuss regional/epidural anaesthesia
o Keep the second stage short
o Use syntocinon judiciously