Cardiac disease in pregnancy Flashcards
What is the pre-conception management of cardiac disease in women wanting to become pregnant?
- Full assessment by obstetrician and cardiologist should be carried out before embarking on pregnancy
- Optimise medications
- Surgically correct the heart defect if possible
What symptoms should you check for antenatally in women with cardiac disease?
- Breathlessness particularly at night
- Change in heart rate or rhythm
- Increased fatigue
- Reduction in exercise tolerance
O/E: check HR, BP, JVP, auscultation, ankle/sacral oedema, basal crepitations
NB: should be seen in joint obstetric/cardiac clinic by same physicians for continuity of care and to detect subtle changes in maternal wellbeing. Sometimes these are difficult to distinguish from normal pregnancy symptoms.
What classification is used for assessing stages of heart failure?
NYHA classification - New York Heart Association classification
4 classes, mild to severe
Summarise the stages of heart failure according to the NYHA classification
1 - mild - no limitation and no symptoms
2 - mild - slight limitation + symptoms during normal activity
3 - moderate - marked limitation + symptoms during light activity
4 - severe - inability to carry out activities without discomform + symptoms at rest + more discomfort during activity
What are the Toronto risk markers for maternal cardiac events?
- Prior episode of heart failure, arrhythmia or stroke
- NYHA class >II or cyanosis
- Left heart obstruction
- Redced LV function (EF<40%)
How does number of Toronto risks markers correspond to risk of cardiac event during pregnancy?
Importance:
- 0 predictors = risk of cardiac event is 5%
- 1 predictor = risk of cardiac event is 37%
- >1 predictor = risk of cardiac event is 75%
When should echocardiograms be done in women with cardiac disease during pregnancy?
- At booking visit
- At 28 weeks
- When there is any sign of deteriorating cardiac function
What cardiac conditions warrant anticoagulant use during pregnancy?
- Congenital heart disease - pulmonary hypertension or artificial valve replacement
- Risk of AF
Why can warfarin not be used in pregnancy?
First trimester - teratogenic
Third trimster - linked with fetal intracranial haemorrhage
What anticoagulant is routinely used in pregnancy?
LMWH e.g. dalteparin/enoxaparin - this is titrated by measuring factor Xa levels
List 4 high-risk cardiac conditions in pregnancy.
- Systemic ventricular dysfunction (ejection fraction <30%, NYHA Class III–IV).
- Pulmonary hypertension.
- Cyanotic congenital heart disease.
- Aortic pathology (dilated aortic root >4 cm, Marfan syndrome).
- Ischaemic heart disease.
- Left heart obstructive lesions (aortic, mitral stenosis).
- Prosthetic heart valves (metal).
- Previous peripartum cardiomyopathy.
What are the fetal risks of maternal cardiac disease?
- Recurrence (congenital heart disease).
- Maternal cyanosis (fetal hypoxia).
- Iatrogenic prematurity.
- FGR.
- Effects of maternal drugs (teratogenesis, growth restriction, fetal loss).
What are the general principles of management of labour in a pregnancy with cardiac disease?
- Avoid IOL if possible - although may be necessary to ensure all relevant personnel are present at time of labour
- Use prophylactic antibiotics - esp if structural heart defect present, to prevent endocarditis
- Ensure fluid balance.
- Avoid the supine position.
- Discuss regional/epidural anaesthesia/analgesia with senior anaesthetist - to relieve pain-related stress and demand on cardiac function BUT can cause maternal hypotension
- Keep the second stage short.
- Use Syntocinon judiciously.
What are the delivery options for a patient with cardiac disease in pregnancy?
Await spontaneous labour - minimises risk of intervention.
Consider IOL - to ensure delivery occurs at time when all relevant personnel are present
+/- Instrumental delivery - to shorten 2nd stage of labour if normal delivery does not readily occur
Elective C-section - only done if maternal condition is too unstable to tolerate labour
What are the risk factors for development of cardiac disease in pregnancy?
- Respiratory or urinary infections
- Anaemia
- Obesity
- Corticosteroids
- Tocolytics
- Multiple gestation
- HTN
- Arrhythmias
- Pain-related stress
- Fluid overload
How common is MI in pregnancy and what is the pathophysiology?
1 in 15,000 risk of MI during pregnancy
Usually not atherosclerosis but rather coronary artery dissection is the primary cause, occurring in the postpartum period.
What treatments for MI can be used in pregnancy?
Percutaneous transluminal coronary angioplasty (PTCA) - only use when absolutely necessary and avoid outside of 8-15 weeks where fetus is most susceptible to effects of radiation
Thrombolysis - little evidence but apparently safe, although increases risk of fetal and maternal haemorrhage
NB: MI is often missed in pregnancy
Why are obstructive lesions of the left heart problematic in pregnancy?
Left heart defects include mitral and aortic stenosis
These are problematic as there is inability to increase CO to meet the demands of the pregnancy
What is the aetiology of most left heart obstructive lesions?
Mitral stenoiss - rheumatic in origin
Aortic stenosis - usually congenital
How does pregnancy affect mitral stenosis?
- 40% experience worsening symptoms
- average time of onset of pulmonary oedema is 30 weeks
- maternal mortality is 2% and fetal mortality depends on severity of MS
What is the management of mitral stenosis in pregnancy?
Aim is to reduce HR:
- Bed rest
- Beta blockers, duiretics
- Balloon mitral valvotomy after delivery
What are the complications of AS in pregnancy?
Pregnancy usually well-tolerated in those with mild/moderate AS with normal exercise tolerance and good ventricular function
Severe AS increases maternal mortality to 17% and fetal mortality to 30%
What is the management of AS in pregnancy?
- Bed rest
- Medical treatment to reduce heart rate to allow time for ventricular filling
- Balloon or surgical aortic valvotomy - if condition deteriorates.
What are the effects of Marfan syndrome on the heart?
- Mitral valve prolapse
- Aortic regurgitation
- Aortic root dilatation
- Aortic rupture or dissection
Marfan’s is a connective tissue abnormality.
