Anaesthesia and peripartum cardiomyopathy

Question 1

Incidence of peripartum cardiomyopathy

Answer 1

1 in 1000

Question 2

Pathophysiology of peripartum cardiomyopathy

Answer 2

Unknown, theories…
- SIRS-like response due to increased reactive oxygen species produced by the placenta
- prolactin inducing apoptosis, endothelial dysfunction and cardiac myocyte inflammation which may explain why cardiomyopathy presents in late pregnancy and the postpartum period

Question 3

ECG findings in peripartum cardiomyopathy

Answer 3

• BBB
• ST segment depression
• T wave inversion
• Ventricular ectopics
• Prolonged QT

Question 4

Differential diagnosis for peripartum cardiomyopathy

Answer 4

• Pulmonary embolism
• Amniotic fluid embolism
• Pre-eclampsia
• Myocarditis
• Other causes of cardiomyopathy
• Valvular heart disease
• Ischaemic heart disease
• Congenital heart disease

Question 5

Factors associated with a poor prognosis with peripartum cardiomyopathy

Answer 5

• African ethnicity
• Previous peripartum cardiomyopathy
• LVEF <30% at time of diagnosis
• LV dilatation
• RV dysfunction
• Prolonged QT
• LV thrombus
• Obesity

Question 6

Pharmacological management of peripartum cardiomyopathy

Answer 6

• Loop diuretics
• B-blockers (commonly metoprolol)
• Hydralazine
• Nitrates
• Digoxin
• Consider ACEi after birth

Question 7

Management of decompensated peripartum cardiomyopathy

Answer 7

• Optimise pre-load: cautious fluid challenge or consider loop diuretic if evidence of pulmonary oedema. If sys >110 then consider GTN infusion
• Optimise oxygenation
• Correct haemodynamic instability with vasopressors and or ionotropes
• Urgent delivery if remains haemodynamically unstable despite above
• Consider bromocriptine (dopamine agonist) and anticoagulation post-delivery

Question 8

Intrapartum management aims for patients with peripartum cardiomyopathy

Answer 8

• Care in an appropriate environment with healthcare staff experienced in managing cardiac disease
• Additional monitoring- ECG, SpO2, low threshold for arterial line
• Bedside-focused TTE and lung USS
• An early epidural is recommended
• Low threshold for the use vasopressors to support epidural
• Caution with utertonics
• Close fluid balance monitoring
• VTE precautions after delivery

Question 9

Benefits of early epidural in patients with peripartum cardiomyopathy

Answer 9

• Reduced concentrations of circulating adrenaline and noradrenaline reducing myocardial O2 demand
• Reduced afterload by ablating pain
• Can be topped up slowly if needed for a caesarean to avoid GA

Question 10

Post-delivery considerations for patients with peripartum cardiomyopathy

Answer 10

• Rapid increase in preload following auto-transfusion from placental removal and relief of aortocaval compression can precipitate decompensation
• PPH is poorly tolerated
• Slow bolus of oxytocin 2 units over 10 mins to reduce associated tachycardia and dropped SVR
• Avoid carboprost as increases pulmonary vascular resistance significantly
• Avoid ergometrine as it causes an acute increase in SVR