Heart Disease

Heart disease in pregnancy is associated with a significant increased risk of maternal & fetal morbidity & mortality. At the first antenatal visit, all women must be asked about a history of heart disease, & should undergo a clinical examination of the cardiovascular system.

Symptoms of heart disease include:

• Progressive dyspnoea
• Orthopnoea
• Haemoptysis
• Palpitations
• Chest pain
• Dizziness

Signs of heart disease:

• Rapid (≥100/min) or irregular heart rate
• Cyanosis
• Clubbing
• Heart murmurs
• Cardiomegaly

ANTENATAL CARE

All women with a history, or with symptoms and signs of heart disease, should be referred, ideally to an obstetric cardiac clinic, run jointly by an obstetrician & a cardiologist.

Principles of antenatal care

• All pregnant cardiac patients should have an echocardiogram, chest X-ray & ECG
• A New York Heart Association (NYHA) grading is assigned to each patient
  • (I = no dyspnoea, II = dyspnoea with moderate exertion, III = dyspnoea with mild exertion, IV = dyspnoea at rest)
• Termination of pregnancy may be recommended for patients with severe cardiac disease early in pregnancy (NYHA grade III or IV), cyanotic congenital heart disease, or those with right-to-left shunt reversal (Eisenmenger syndrome)
• Women with congenital heart disease require detailed ultrasound scanning at the Fetal Medicine Unit to identify fetal heart defects
• Infection, anaemia & arrhythmias must be prevented, identified & treated
• Diuretics, vasodilators, beta-blockers or antiarrhythmics are given if required
• Anticoagulation, if needed, is given as described below
• Induction of labour or elective caesarean section are usually recommended only for obstetric indications

LABOUR IN WOMEN WITH HEART DISEASE 

Consider 5 As: Analgesia, Antibiotics, Anticoagulation, Anti-failure measures, Assisted delivery

First stage

• Admit to a high care area
• Nurse the woman in a semi-Fowler position
• Restrict intravenous fluids - Ringer-Lactate or Normal saline 70 mL/hour
• Give adequate analgesia – pethidine 1 mg/kg IM with metoclopramide 10 mg IM 4 hourly.  Epidural analgesia is useful for cardiac patients without fixed output states
• Give ampicillin 1 g IV 6 hourly for 4 doses & gentamicin 240 mg IV as a single dose, as prophylaxis against infective endocarditis
• Vancomycin 1 g IV as a single dose for women allergic to penicillin
• Observe colour, heart rate, BP & respiratory rate hourly
• Auscultate the lung bases 2 hourly
• If augmentation of labour is necessary, give oxytocin in a 200 mL infusion bag

Second and third stages

• Avoid the lithotomy position – the woman must sit up with her legs supported below the level of her body, by assistants or on chairs
• Perform a forceps delivery or vacuum extraction for NYHA grade III and IV, unless delivery is rapid & easy
• Local anaesthetics for episiotomy should not contain adrenaline
• Do not give ergometrine in the third stage; use oxytocin 10 units IM
• Give furosemide 40 mg IV after delivery of the baby

Fourth stage and puerperium

• Observe closely for evidence of pulmonary oedema
• Do hourly observations of general condition, respiratory rate, heart rate & blood for 24 hours
• When stable, transfer to the postnatal ward
• Breast-feeding is encouraged even on long-term anticoagulation
• Offer contraception – long acting depot progestins (medroxyprogesterone acetate, etonogestrel implant) are safe for women with heart disease
• Delay postpartum sterilization until at least one month after delivery
• Discharge the woman when she is well, with a letter to her doctor or cardiac clinic

PULMONARY OEDEMA

• Nurse in the semi-Fowler position
• Give oxygen by mask
• Restrict intravenous fluid
• Give furosemide 40 mg IV, & repeat if necessary
• Attach an ECG monitor & pulse oximeter if available
• Seek advice from an internal medicine specialist or anaesthetist if there is no rapid response to the above measures

PERIPARTUM CARDIOMYOPATHY (PPCM)

• Development of cardiac failure within the last month of pregnancy & the 5 months post-partum. 
• Absence of identifiable cause for the cardiac failure
• Absence of recognizable heart disease
• Left ventricular systolic dysfunction (LVEF <45%)
• Possible complications: arrhythmias, PE and congestive heart failure.
• Echocardiogram remains the most important tool for the diagnosis & follow up for a patient with PPCM

The management is similar to other form of heart failure except in the women who presents while pregnant where the effects on the fetus should be consider (avoid ACE inhibitors). The aim of the treatment: improve blood flow to vital organs, reduce fluid overload, treat abnormal heart rhythms & prevent complications such as thrombo embolic disease (TED).

• Vasodilators antenatally, ACE inhibitors postpartum
• Diuretics
• B-blockers
• Anticoagulation
• O2 administration

Once stable & before discharge the patient should be strongly counselled about prognosis, future reproductive health and follow up.