This blog post is based on an old yet very important TOG “Myocardial Infarction and Pregnancy” published in 2013. As cardiac disease is the leading cause of maternal death in UK, so this article is a must to cover before the exam.
I hope this summary is helpful.
To download the original article: Click Here
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Outline of Maternal Medicine Module: Click Here
To access other TOG summaries: Click Here
Introduction
- Heart disease
- complicates → 0.2-4% of all pregnancies
- In UK the leading cause of maternal death since 2000
- 1/5th of All maternal deaths
- Majority due to acquired heart disease
- Acute Myocardial Infarction (AMI) → rare but in pregnancy RR is 3-4x higher
- Be aware of pregnancy specific physiological changes in CVS & keep low threshold for dx & mx
Physiological changes in pregnancy
Cardiovascular changes
- ↑ plasma volume & ↓ peripheral resistance as early as 6 wks
- ↑ in blood volume until plateaus at 140-150% @32 wks
- ↑ Cardiac output until 25wk first d/t ↑ in stroke volume & then d/t ↑ in maternal HR
- Further haemodynamic changes during labour & delivery
- Cardiac output→ ↑ by 50% with each contraction
- 300-400ml blood transferred from uterus with each contraction
- Valselva manoeuvre→ large variations in CVP
- After 3rd stage completed→ approx.500 ml uterine blood returns to circulation→ ↑ ventricular preload, cardiac output & CVP
- After 48 hrs→ diuresis & natriuresis starts.
- Return of cardiac output , blood volume & peripheral resistance → pre-pregnancy state 4-12wks
Haematological changes
- Pregnancy a hypercoagulabale state
- ↑ procoagulant: fibrinogen, factor VII, VIII & X & von Willebrand's factor