Cardiac Disease in Pregnancy Flashcards
How has the incidence of cardiac disease changed over time
In the western world, the risk of CVD in pregnancy has increased due to increasing maternal age at first pregnancy- pregnancies in the late reproductive years are more frequently associated with an increased prevalence of cardiovascular risk factors (T2DM, HTN, obesity.)
What are the most commmon CV disorders in pregnancy.
- Maternal heart disease is the major cause of maternal death during pregnancy
- Hypertensive disorders are the most frequent CV disorders during pregnancy- occur in 5-10% of all pregnancies
- CHD is the most frequent other CVD present during pregnancy in the western world (75-82%)
- Rheumatic valvular disease dominates in non-western countries (56-89%)
What physiological adaptations to the cardiovascular system occur during pregnancy
- Pregnancy induces changes to the cardiovascular system to meet the increased metabolic demands of the mother and foetus
- Plasma volume and cardiac output reach a maximum of 40-50% above baseline at 32 weeks gestation (75% of this increase occurs by the end of the first trimester)
- Increase in CO is caused by an increase in stroke volume in the first half of pregnancy and an increase in HR thereafter
- AV diameters increase and both systemic and pulmonary vascular resistances decrease
- Pregnancy is a hyper-coagulable state associated with increased risk of VTE
- Blood pressure (BP) and CO increase during labour and post-partum
Types of cardiac defects commonly seen in pregnancy
- Congenital (PDA, VSD, ASD, coarction of the aorta etc.)
- Acquired: valvular defects, ischaemic heart disease
- Cardiomyopathies: peripartum cardiomyopathy- new onset cardiomyopathy/heart failure (last month of pregnancy- 6 months postpartum)
Mitral valve prolapse, VSD and ASDs do not affect pregnancies
In which condition is pregnancy CONTRAINDICATED
- Pulmonary hypertension- has a high maternal mortality rate (40%)
What condition must be corrected before pregnancy
- Aortic stenosis- causes severe disease due to inability to increase CO
- Mitral valve disease should also be treated before pregnancy (stenosis can lead to heart failure in late pregnancy)
Complications of cardiac disease in pregnancy
- Women with cardiac disease have an increased risk of obstetric complications including premature labour, pre-eclampsia and PPH
- Offspring complications occur in 18-30% of patients, with neonatal morality between 1-4%. Risk of recurrence, foetal hypoxia, prematurity, FGR
Presentation and classification of heart failure in pregnancy
- SOB, palpitations (SOB lying flat), chest pain
- It can be more challenging to diagnose HF, due to physiological changes which can mimic CVD
- HF can be assessed using the NYHA classification
- When disproportionate or unexplained dyspnoea occurs during pregnancy and/or when a new pathological murmur (all audible diastolic murmurs are abnormal) is heard, echocardiography is indicated
Common ECG changes in pregnancy
In most pregnant patients, there is a 15-20° left axis deviation. There may be common additional findings including transient ST/T wave changes, Q wave, inverted T wave in lead III, V1,2,3. Changes may mimic LV hypertrophy
Investigations for cardiac disease
- ECG
- Echocardiography- preferred imaging modality
- Exercise testing
- CXR and CT- should only be performed if other methods fail to clarify the cause of symptoms
- Cardiac catheterisation- seldom needed for diagnostic purposes, but can be necessary to guide interventional procedures
- MRI- preferred to ionising radiation-based imaging where possible.
Pre-pregnancy counselling for all weomen with cardiac disease
- All women with know cardiac or aortic disease require timely pre-pregnancy counselling and discussion in an MDT
- As a minimum, an ECG, echocardiography, and an exercise test should be preformed
- In the case of aortic pathology, complete CT or MRI aortic imaging should be completed
- A pregnancy exercise capacity >80% is associated with a favourable pregnancy outcome
- Should discuss lifestyle modification including smoking and alcohol cessation
- To assess the maternal risk of cardiac complications during pregnancy, the condition of the women should be assessed, taking into account:
Medical history, oxygen saturation, natriuretic peptide levels, Echo assessment of ventricular and valvular function, pulmonary pressures, exercise capability, arrhythmias
Antenatal management of all women with cardiac disease
- Advise to stop all teratogenic drugs (ACEi, ARBs, thiazide diuretics, statins and warfarin)- should ideally be stopped pre-conception
- Should arrange contact with joint cardiac and obstetric clinic
- Maternal echocardiogram should be arranged at booking and repeated at 28 weeks
- Also may require specialist foetal cardiac scan at 19 and 22 weeks
- All women with VTE risk (including HF) should be started on LMWH (warfarin should be avoided since it is teratogenic)
Intrapartum care of women with cardiac disease
- Induction of labour should be considered at 40 weeks in all women with cardiac disease (reduces risk of emergency c-section and stillbirth)
- Both misoprostol and dinoprostone can be used safely to induce labour (as well as ARM)
- Elective c-section carries no maternal benefit and results in earlier delivery and lower birth weight. Vaginal delivery is associated with less blood loss, lower risk of infection, VTE and should be advised in most women
- Instrumental delivery may be preferred according to nature of cardiac lesion
- For women with a planned caesarean section (for obstetric indications), therapeutic low molecular weight heparin (LMWH) dosing can be simply omitted for 24 h prior to surgery
- For high risk patients, VTE prophylaxis can be omitted around 4-6 hours prior to LA or anticipated delivery (In the case of SVD). Can be restarted at 6hrs pot-delivery in both cases
- Must be mindful that epidural analgesia can cause systemic hypotension (10%) and should be carefully titrated
- Maternal BP and heart rate should be monitored in all patients with cardiac disease. In women with more severe heart disease, an arterial line provides more accurate data. Pulse oximetry and continuous ECG monitoring are advised to detect early signs of decompensation
Management of HF in pregnancy
Summary of cardiac diseases and associated risk
