CARDIAC DISEASE IN PREGNANCY

Heart disease should be suspected or diagnosed at booking for antenatal women.

Heart disease may be suspected when a pregnant lady presents with symptoms of,

·        progressive dyspnea or orthopnea,

·        nocturnal cough,

·        hemoptysis,

·        syncope

·        Chest pain.

Heart disease may be suspected when a pregnant lady presents with clinical findings 

·        cyanosis,

·        clubbing,

·        distended neck veins,

·        systolic murmur of grade 3/6 or greater,

·        diastolic murmur,

·        cardiomegaly,

·        persistent arrhythmias,

·        persistent split second sound, 

·        Pulmonary hypertension.

The incidence of heart disease in pregnancy is 1% and it is the third leading cause of death in women of reproductive age group.

Rheumatic Heart Disease (RHD) remains an important cause of heart disease especially in developing countries.

With advances in paediatric cardiac surgery more women with congenital heart disease (CHD) are now surviving and reaching child bearing age.

Ischemic heart disease is also on the rise as a result of increase prevalence of obesity, hypertension and diabetes in young adults and delayed child bearing.

Maternal mortality is higher in conditions that restrict an increase in pulmonary blood flow especially pulmonary hypertension and mitral stenosis. The situation is at its worst in Eisenmengers syndrome, where the mortality is 25 to 50 %.

Other cardiac complications associated with pregnancy include infective endocarditis, cardiac arrhythmias, development of cardiomyopathy.

Fetal outcome in pregnancies complicated by maternal RHD is usually good although there is an increased incidence of growth restriction and preterm birth.

The effects of maternal anticoagulant therapy with warfarin could lead to abortions, stillbirths , warfarin embryopathy in live born infants.

Anticoagulation may be indicated in certain cardiac conditions such as mechanical heart valves, atrial fibrillation and pulmonary hypertension.

Fetal growth restriction and preterm birth are more common in pregnancies complicated by CHD with restricted maternal cardiac output, especially poor in cyanotic varieties when the fetal wastage rates may be as high as 40%.

 Incidence of CHD in the offsprings of parents with CHD ranges from 5 -10%. However, risk may be as high as 50% as in Marfan’s syndrome.

PREVENTION AND COUNSELING

Women may be aware of their cardiac condition before becoming pregnant. An assessment of the patient’s clinical status and ventricular function are necessary to predict the outcome of pregnancy.

A Cardiologist should be involved in initial assessment and follow-up.

Women with following conditions should be counseled for early termination of pregnancy to avoid maternal mortality.

·        pulmonary hypertension,

·        severe left sided obstructive lesions,

·        dilated aortopathy(>4cm)

·        severe systemic ventricular dysfunction

Concurrent medical problems like infections, anaemia should be aggressively treated.

Pneumococcal and influenza vaccines are recommended to avoid respiratory infections precipitating cardiac failure.

Women with cardiac disease should be counseled regarding the risk of maternal death, possible reduction in maternal life expectancy, fetal issues, need for timely switch over of anticoagulant therapy, need for frequent hospital attendance and possible admission, intense feto-maternal monitoring during labour.

Investigations:

FBC

Nonivasive studies like electrocardiography, echocardiography.

Treatment:

Clinical Classification Schemes commonly used are that of NYHA

These classification systems are useful to clinicians to evaluate the functional capacity and to aid in counseling the woman regarding advisability of conception or continuation of pregnancy.

New York Heart Association (NYHA) Classification Scheme:

Class 1 - Uncompromised. No limitation of physical activity.

Class II - Slightly compromised. Slight limitation of physical activity.

Class III - Markedly compromised. Marked limitation of physical activity.

ClassIV - Severely compromised. Inability to perform any physical activity

Without discomfort

Risk of Maternal mortality Caused by Various Types of Heart Disease

Group 1 - Minimal Risk 0-1%

Ø Atrial septal defect

Ø Ventricular septal defect

Ø Patent ductus arteriosus

Ø Pulmonic or tricuspid disease

Ø Corrected Tetrology of Fallot

Ø Bioprosthetic Valve

Ø Mitral stenosis (NYHA Classes 1and II)

Group 2- Moderate Risk 5-15%

Ø Mitral stenosis (NYHA Classes III and IV)

Ø Aortic stenosis

Ø Aortic coarctation without valvar involvement

Ø Uncorrected Fallot tetrology

Ø Previous myocardial infarction

Ø Marfans syndrome, normal aorta

Ø Mitral stenosis with atrial fibrillation

Ø Artificial valve

Group 3- Major risk 25-50%

Ø Pulmonary hypertension

Ø Aortic coarctation with valvar involvement

Ø Marfan syndrome with aortic involvement

The management in most instances is by a multidisciplinary team involving:

Ø Obstetrician

Ø Physician /Cardiologist

Ø Anaesthetist

Ø Paediatrician

Most women with functional Class 1 and 2 go through pregnancy without morbidity. However, special attention should be directed toward both prevention and early recognition of heart failure.

Indicators being cough, progressive edema, tachycardia, hemoptysis and basal crepts.

Empirical therapy with diuretics and beta-blockers could be hazardous, so opinion of cardiologist /physician should be taken.

Labour and Delivery:

Vaginal delivery is recommended unless there is an obstetric indication for caesarean section.

Await spontaneous onset of labour. Avoid induction of labour to minimize risk of intervention thereby haemorrhage and infections. However, despite the increased risks of hemorrhage, infection and large fluid shifts, there are a few conditions in which labor is ill-advised and cesarean delivery is recommended:

·        Dilated aortic root ( >4cm) or aortic aneurysm

·        Acute severe congestive heart failure

·        A history of recent myocardial infarction

·        Severe symptomatic aortic stenosis

·        Warfarin administration within 2 weeks of delivery

·        Need for emergency valve replacement immediately after delivery

Careful fluid balance should be monitored. Avoid supine position. A semi recumbent position with lateral tilt preferred.

Monitor vitals - pulse, respiration, BP, Oxygen saturation and intake output.

Epidural analgesia by a skilled senior anaesthetist considering its hypotensive effect.

Cut short 2nd stage of labour with outlet forceps or vacuum extractor to reduce maternal effort.

Infective endocarditis prophylaxis is recommended preferably 30-60 minutes before the procedure. Either Ampicillin 2g or Ceftriaxone 1g is given iv ( ±1g vancomycin if Enterococcus infection is a concern) 600mg Clindamycin iv is recommended in cases of Penicillin allergy.

Avoid methyl ergometrine which causes intense vasoconstriction, hypertension and heart failure. use syntocinon .

Close monitoring of cardiac patient should continue after delivery because early postpartum period is often a time of acute de-compensation.