Peripartum cardiomyopathy
Peripartum cardiomyopathy is associated with the onset of cardiac failure in the last month of pregnancy up to 5 months post-partum, with no identifiable cause and in the absence of pre-existing heart disease. It was responsible for 11 deaths in the last CEMACH report (2006–08), with one of these deaths being a late death. It has an incidence of 1:1200–4000 live births, with most cases occurring post-partum. The aetiology of this condition is poorly understood but may be an exaggerated immune response to pregnancy or due to viral, autoimmune, or toxic factors. It is associated with older maternal age, greater parity, black race, and multiple gestations. Women may present with fatigue, dyspnoea, oedema, orthopnoea, paroxysmal nocturnal dyspnoea, chest pain, and nocturnal cough. The diagnosis can be missed, as the symptoms may be attributed to those of pregnancy. On examination, there may be an elevated JVP, hepatomegaly, a new regurgitant murmur, and bibasal crepitations.
1 Acknowledge the differential diagnoses of a parturient presenting with cardiac failure
2 Appreciate the benefits of shared care with the obstetric and cardiology services for patients with peripartum cardiomyopathy
3 Optimally plan the anaesthetic input to delivery with regards to appropriate analgesia and cardiovascular monitoring.
2B05; 2B06
Your patient is 37 years old, of parity 2 + 1, with two previous normal deliveries at term. She is now 37 + 6 weeks pregnant and presents to the obstetric triage with increasing fatigue, worsening ankle oedema, and shortness of breath on exertion. On further questioning, her breathlessness has been deteriorating over the past couple of weeks, and she finds herself short of breath mobilizing within the house and has been unable to get out of the house in the past week. She has been waking up at night, coughing and out of breath, and is sleeping with four pillows to prop herself up. She has had occasional episodes of chest pain lasting up to 45 minutes at a time. She has no significant past medical history, is not on any medication, and has no allergies. She smokes ten cigarettes a day.
On examination, the patient has just returned from the toilet and appears dyspnoeic, and her face looks a little puffy. She has a regular pulse of 110 bpm, BP 100/65 mmHg, oxygen saturations 93% on air; her JVP is elevated at 6 cm. She has bilateral coarse crackles on chest examination and an audible 3rd heart sound. Abdominal examination is unremarkable, with a fundal height of 38 cm. Her CTG is reassuring with a baseline of 130 bpm, with good variability and accelerations. There is no uterine activity noted.
Her bloods show Hb 110 g/L, WCC 13.4 × 109/L, Plt 237 × 109/L, urea 4.5 mmol/L, Na+ 131 mmol/L, K+ 3.6 mmol/L, Cr 58 mmol/L, urate 0.4 mmol/L. Her blood group is A positive, and a group and save has been performed.
◆ Peripartum cardiomyopathy
◆ Other cardiomyopathy
◆ Sepsis
◆ Lower respiratory tract infection (LRTI)
◆ Pre-eclampsia
◆ Ischaemic heart disease with possible MI
◆ PE.
◆ CXR: shows upper lobe diversion with some fluid in the horizontal fissure, suggestive of LV failure
◆ ECG: shows sinus tachycardia, with occasional ventricular ectopics. There is left axis deviation and inverted T waves inferiorly. Sinus tachycardia is a frequent finding in pregnant women, as is the left axis deviation that occurs, due to the displacement of the heart by the gravid uterus. Non-specific T wave changes are also not uncommon
◆ Echocardiography: shows an ejection fraction of <25%, with LV shortening of around 10% (normal is >30%) and end-diastolic dimension of 6 cm. This is severe LV dysfunction.
In view of an absent past history of any cardiac condition, this is likely to be peripartum cardiomyopathy.
A multidisciplinary approach is required. The consultant obstetrician, anaesthetist, and cardiologist should be involved.
All patients are likely to be commenced on diuretics, oxygen, digoxin, and vasodilators, e.g. nitrates or amlodipine. She should also be commenced on LMWH, in view of her ejection fraction of <35% which predisposes her to a mural thrombus. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin-2 antagonists are contraindicated in the pregnant state, as they may cause neonatal kidney malformations.
Your patient’s condition deteriorates over the next 48 hours, with increasing oxygen requirements. She is dyspnoeic at rest and unable to lie flat. She now has crackles to her midzones despite treatment. CTG remains reassuring. A speculum examination shows a parous os, and the cervix is 2 cm long and 2 cm thick.
Delivery needs to be expedited. The mode of delivery needs to be discussed with the patient and the obstetricians. This lady is decompensating. Because the pregnancy is near term, there is no great benefit to the fetus in delaying delivery. She should be managed in a tertiary referral centre.
The benefits of a vaginal delivery include reduced blood loss, greater haemodynamic stability, avoidance of surgical stress, and reduced post-operative infections and pulmonary complications. The anaesthetic management of this course of action should include:
◆ A planned induction so that anticoagulants can be appropriately omitted
◆ She would benefit from arterial and central line monitoring during labour, and she requires careful fluid management, oxygen therapy, and diuretics, in view of her LV failure
◆ Early epidural for labour to reduce cardiovascular stress and also is beneficial in reducing afterload
◆ A shortened second stage to reduce cardiac work. Elective forceps with Syntocinon® infusion 10 IU in 100 mL of saline over 30 min.
This patient is induced, but her CTG is unreassuring, and it is decided that she requires a Caesarean section. She now has 6-pillow orthopnoea. She has not had any anticoagulant for >12 hours.
Operative delivery of this patient should involve a consultant anaesthetist, and ideally a cardiac anaesthetist should be available. A regional technique, such as an epidural or a CSE, are feasible options, but, in view of the severity of her dyspnoea, this lady will be unable to lie flat for surgery, and, as a consequence, she will require a general anaesthetic. The anaesthestic planning should include:
◆ Antacid prophylaxis with ranitidine and sodium citrate prior to induction
◆ Large-bore IV access and arterial line sited prior to induction
◆ Minimize pressor response to laryngoscopy with an opiate (alfentanil or remifentanil)
◆ Thiopentone and suxamethonium for RSI with cricoid pressure
◆ Vasopressors prepared: phenylephrine to offset the vasodilation caused by general anaesthesia. Also have prepared noradrenaline, dobutamine, or adrenaline for infusion
◆ Once anaesthetized and delivered, it may be of benefit to insert a CVC or pulmonary artery catheter to optimize the post-operative cardiac management
◆ Ventilate with increased PEEP to help LV failure
◆ Restrict fluid intake to losses plus 80 mL/hour, and insert a urinary catheter to guide subsequent fluid therapies
◆ Syntocinon® 10 IU in 100 mL over 30 min following cord clamping
◆ Give a dose of furosemide after delivery, ensuring there is no hypotension following the Syntocinon® dose.
She should be cared for in an ICU/HDU/coronary care unit (CCU) setting with cardiology input. She should be commenced on an ACE inhibitor. If she is keen to breastfeed, then enalapril and captopril are felt to be the safest. She requires thromboprophylaxis, due to the risk of intracardiac and pelvic thrombi.
About 50% of patients recover to a normal ejection fraction. This is more likely if the ejection fraction at diagnosis was >30%. Recovery should occur within 6 months. If there is no improvement by 6 months, then the 5-year mortality is 85%. The cardiac transplant rate is 14%.
There is a high recurrence rate for peripartum cardiomyopathy, so she should have contraceptive advice and be warned against any further pregnancies.
Summary
When managing the patient with peripartum cardiomyopathy, a standard vaginal delivery is optimal in the majority of cases, once the woman is stabilized. The advantages of this mode of delivery are the reduction in haemorrhage, greater haemodynamic stability, avoidance of surgical stress, and reduced post-operative infections and respiratory complications.
Adamson DL, Dhanjal MK, and Nelson-Piercy C (2011). Cardiomyopathies. In: Adamson DL, Dhanjal MK, and Nelson-Piercy C, eds. Heart disease in pregnancy, pp. 137–50. Oxford University Press, Oxford.
Royal College of Obstetricians and Gynaecologists (2011). Cardiac disease and pregnancy (Good practice No. 13). Available at: <http://www.rcog.org.uk/cardiac-disease-and-pregnancy-good-practice-no-13>.
Sliwa K, Hilfiker-Kleiner D, Petrie MC, et al. (2010). Current state of knowledge on aetiology, diagnosis, management, and therapy of peripartum cardiomyopathy: a position statement from the Heart Failure Association of the European Society of Cardiology Working Group on peripartum cardiomyopathy. European Journal of Heart Failure, 12, 767–78.