Cardiac disease in pregnancy

Question 1

Define

Define

Answer 1

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

Question 2

Symptoms

Answer 2

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)

Question 3

Investigations

Answer 3

echocardiogram is usually performed at booking and at 28 weeks

Question 4

Management

Answer 4

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

Question 5

Summary

Answer 5

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