Cardiac

Question 1

What are the physiological changes to the cardiovascular system in pregnancy?

Answer 1

• Increased 02 consumption due to metabolic needs of mother and foetus
• Increased plasma volume to facilitate the exchange of nutrients and respiratory gases between mum and foetus
• Increased RBC’s
• Decreased resistance in systemic circulation = cardiac output increases to compensate for this (HR ^ 10-20bpm)
• Increased stroke volume
• CO = HR x SV = Increased CO by 20% by 8 weeks and 40% by 20 - 28 weeks
• By term heart is dilated and myocardial contractility is increased
• BP decreased in 2nd trimester then reaches or exceeds pre pregnancy levels by term
• CVP is unchanged
• Colliod oncotic pressure falls by 10-15% which makes pulmonary oedema more likely
• Increased oedema of hands, feet and ankles

Question 2

What are the cardiac changes in labour?

Answer 2

• 15% increase in CO in first stage and 50% in second
• Following delivery, relief of IVC compression and contraction of uterus = auto transfusion of blood back into circulation which increases CO by 60-80%. Most risky time for pulmonary oedema
• Return to normal level by 2 weeks PN

Question 3

What is the cardiac AN care?

Answer 3

• Multi disciplinary team work
• Increased AN visits
• Continuity of midwifery care
• Psychological and social support

Question 4

Recognition of cardiac compromise

Answer 4

• Fatigue, dysponea, orthoponea, peripheral oedema
• Progressive limitation of physical activity
• Chest pain that accompanies activity
• Fainting proceeded by palpitations

Question 5

What are the investigations into cardiac compromise?

Answer 5

• EGC
• FBC and clotting studies
• Heart and lung sounds
• Heart USS
• Chest X-ray