Cardiac disease Introduction to cardiac disease

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Cardiac disease

Introduction to cardiac disease

The incidence of heart disease in pregnancy is rising and cardiac disease is now the most common cause of maternal death. Unfortunately, care for pregnant women with heart disease is frequently suboptimal.

This tutorial will help you to learn more about the way in which heart disease can complicate pregnancy, and how to assess and manage pregnant women with cardiac problems.

Learning objectives

When you have completed this tutorial you will be able to:

describe the epidemiology of heart disease in pregnancy understand the physiological cardiovascular changes that occur in pregnancy understand the pathophysiology of heart disease in pregnancy describe the clinical characteristics of various congenital and acquired heart diseases in

pregnancy outline the management principles used for women with various types of heart disease in

pregnancy.

Preliminary assessments

Answer true or false - Women with the following conditions should be counselled that they would be at high risk of serious morbidity or death if they became pregnant:

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Answer whether the following statements are true or false.

Wolff-Parkinson-White syndrome.

True

False

Correct

The answer is false.

Eisenmenger syndrome.

True

False

Correct

The answer is true.

Mild mitral stenosis.

True

False

Correct


Primary pulmonary hypertension.

True

False

Correct

The answer is true.

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Marfan syndrome with a dilated aortic root.

True

False

Correct

The answer is true.

With regard to peripartum cardiomyopathy, answer whether the following statements are true or false.

It usually occurs in the last month or pregnancy or the first 2 months after delivery.

True

False

Correct

The answer is true.

Risk factors include multiple pregnancy, hypertension and multiparity.

True

False

Correct

The answer is true.

Cardiac transplantation is inappropriate.

True

False

Correct

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Anticoagulation is required.

True

False

Correct

The answer is true.

Cerebral embolisation is a major cause of mortality.

True

False

Correct

The answer is true.

Answer true or false to the following general cardiac questions.

Maternal deaths with Eisenmenger syndrome usually occur before delivery.

True

False

Correct


Congenital heart disease is numerically more important than acquired heart disease as a cause of maternal mortality in Britain.

True

False

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Correct


Pregnant women are less susceptible than nonpregnant women to cystic medial necrosis of the aorta.

True

False

Correct


The maternal mortality from Eisenmenger syndrome is approximately 20–40%.

True

False

Correct

The answer is true.

If myocardial infarction is considered as a cause of chest pain in a pregnant woman, then a troponin test is a useful investigation.

True

False

Correct

The answer is true. Troponin is as reliable in pregnancy as in the nonpregnant population.


Most murmurs first detected in pregnancy are due to mitral regurgitation.

True

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False

Correct


Heart disease due to rheumatic fever is the most common cardiac complication of pregnancy in the UK.

True

False

Correct


The number of women with congenital cardiac lesions reaching childbearing age has decreased.

True

False

Correct


The number of maternal deaths due to cardiac disease continues to fall.

True

False

Correct



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Severe cardiac disease is a contraindication to ergometrine administration.

True

False

Correct

The answer is true.

An intrauterine contraceptive device (IUCD) is the contraceptive method of choice for the patient with valvular heart disease.

True

False

Correct


Beta-blocking drugs are contraindicated in the pregnant patient.

True

False

Correct


Vasodilatation increases afterload.

True

False

Correct


If a soft (2/6) ejection systolic murmur is heard it should prompt further investigation by

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echocardiography.

True

False

Correct


The increasing number of maternal deaths in women with heart disease is because women with severe congenital heart disease are now surviving until adulthood and embarking on pregnancies.

True

False

Correct


Answer true or false whether the following features indicate heart disease in pregnancy:

The presence of a third heart sound.

True

False

Correct

The answer is true.

The apex beat is palpable in the axilla.

True

False

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Correct

The answer is true.

An early diastolic murmur.

True

False

Correct

The answer is true.

Regarding cardiovascular drugs with possible adverse fetal effects, answer whether the following statements are true or false.

Amiodarone hydrochloride (anti-arrhythmic) may cause neonatal goitre if given to a mother during pregnancy.

True

False

Correct

The answer is true.

Angiotensin-converting enzyme (ACE) inhibitors may affect fetal renal function.

True

False

Correct

The answer is true.

Methyldopa may cause a positive Coombs test in the neonate.

True

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False

Correct

The answer is true.

Warfarin is contraindicated during breastfeeding.

True

False

Correct


Epidemiology

Maternal mortality from cardiac disease

Maternal deaths from cardiac disease continue to rise.

Maternal deaths from congenital and acquired heart disease

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The increase in cardiac deaths is due to an increase in deaths from acquired heart disease.

Gelson E, Gatzoulis M, Steer P, Johnson M. Heart disease – why is maternal mortality increasing?BJOG 2008;116:609–11.

Increased incidence of maternal deaths during pregnancy due to cardiac problems

Reasons include:

hypertension increasing maternal age obesity smoking congenital – increased expectations immigration – undiagnosed congenital heart disease immigration – increasing rheumatic heart disease lack of awareness of staff

Most common causes of maternal death during pregnancy

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Centre for Maternal and Child Enquiries. Saving Mothers’ Lives: reviewing maternal deaths to make motherhood safer: 2006–08. The Eighth Report on Confidential Enquiries into Maternal Deaths in the United Kingdom. BJOG 2011;118Suppl 1:1–203.

Cardiac disease has been the most common cause of maternal death in the last two triennial Confidential Enquiries. It is more common than the most frequent 'direct' cause of maternal death, sepsis.

Some degree of substandard care was present in over half the cases (51%), so learning about the causes of cardiac deaths and their management can help us improve the care we provide for women with heart disease during pregnancy.

Causes of maternal cardiac deaths (indirect):

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In addition, there were two further late deaths from peripartum cardiomyopathy.

Cardiac disease can be divided into congenital heart disease and acquired heart disease. Pulmonary hypertension is the main cause of death in women with congenital heart disease; myocardial ischaemia, Sudden Adult Death Syndrome (SADS), peripartum cardiomyopathy and aortic dissection are the main causes of death in women with acquired heart disease. More women who die from cardiac disease, die post partum rather than antenatally.

Cardiac definitions EMQ

A: Left atrial pressure

B: The load that opposes shortening of myocardial fibres during ventricular contraction

C: Ratio of stroke volume to end diastolic volume

D: Ventricular end diastolic volume

E: Right atrial pressure

F: Ratio of end diastolic volume to stroke volume

G: The load that opposes shortening of myocardial fibres during atrial contraction

Preload

Incorrect

The answer is ventricular end diastolic volume

Afterload

Incorrect

The answer is the load that opposes shortening of myocardial fibres during ventricular

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contraction

Ejection fraction

Incorrect

The answer is ratio of stroke volume to end diastolic volume.

Central venous pressure

Incorrect

The answer is right atrial pressure

Pulmonary capillary wedge pressure

Incorrect

The correct answer is left atrial pressure

Physiological changes during pregnancy

During pregnancy, oxygen consumption increases. This is partly because the fetus has its own increasing oxygen requirements and partly because of the increasing size of the uterus and increasing maternal metabolic rate. Physiological changes in the maternal cardiovascular system occur in order to increase delivery of oxygenated blood to the tissues.

Main effects of pregnancy on the cardiovascular system

The associated effects of pregnancy on the cardiovascular system are:

reduced systemic vascular resistance – decreased afterload increased heart rate by approximately 10 bpm increased plasma volume – increased preload

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increased stroke volume increased cardiac output by 30–50%. Half of the total increase occurs by 8 weeks of gestation.

Click on the play buttons to view these animations.

View large version

Physiological changes in pregnancy

Systemic and pulmonary vascular resistance fall during pregnancy. Blood pressure may fall in the second trimester, rising slightly in late pregnancy. Note that cardiac output and stroke volume peak by week 16 of gestation. Times when women with heart disease are at greatest risk are the times when cardiac output is high or changing rapidly. Early pregnancy, second stage and immediately postpartum are the times of greatest change.

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What is the ejection fraction likely to be during a normal pregnancy?

100%

60%

40%

20% Correct

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ECG changes during pregnancy

ECG changes that are physiological, not pathological, during pregnancy are:

atrial and ventricular ectopics left shift in the QRS axis small Q wave and inverted T wave in lead III ST segment depression and T wave inversion in the inferior and lateral leads.

During pregnancy, the ECG is more useful in diagnosing arrhythmias than in assessing structural abnormalities.

Classification/prognostic indicators

The New York Heart Association (NYHA) classification system is an assessment of functional impairment, which is decided by taking an accurate history. It describes the severity of the cardiac disease, but does not give prognostic information.

Class I No limitation of physical activity. No symptoms with ordinary exertion Class II Slight limitation of physical activity. Ordinary activity causes symptoms Class III Marked limitation of physical activity. Less than ordinary activity causes symptoms.

Asymptomatic at rest Class IV Inability to carry out any physical activity without discomfort. Also symptoms at rest

In the scoring system, a woman scores one for each of the following:

cyanosis (Sa02 <90%) or poor functional class (NYHA >2) left heart obstruction systemic ventricle ejection fraction <40% prior CVS event (pulmonary oedema, arrhythmia, CVA/TIA).

The score is totalled:

Score (number of risk factors present) Chance of cardiac complications in pregnancy 0 5% 1 27% >1 75%

Case-based discussion

A woman who speaks very little English attends for preconceptual care. She has congenital heart disease (tricuspid atresia treated surgically) and pulmonary hypertension. She is

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cyanosed and has oxygen saturations of 83% in air. She finds it difficult to perform light housework, but is not breathless at rest. Her mother-in-law tells you that she is keen to become pregnant. She is currently taking warfarin and captopril.

Discuss the following questions with your peers:

what NYHA functional class would you assign? what is her chance of cardiac complications in pregnancy? what would you cover during this consultation?

A model answer can be found on the next page.

Discussion points

Any preconceptual counselling appointment should include particular points of discussion.

Attitudes and practices that value the individual and the family

For the woman mentioned in the case-based discussion, this would include an acknowledgement of her social and cultural context, and should avoid making assumptions. It is important to speak to the woman alone with a professional interpreter (not a family member).

Information and choice

A full, open and frank discussion of the risks involved in pregnancy, including the risk of dying, would be important. Options, including contraception and adoption should be discussed. Information should be given about how to access termination of pregnancy easily if an unplanned pregnancy occurs.

Active preparation for pregnancy: optimise health

If the woman wishes to consider pregnancy, the need for, and alternatives to, teratogenic drugs should be considered. As with all women, preconceptual folic acid should be advised. Appropriate information about how to access services promptly if a pregnancy is confirmed should be provided. Appropriate care in a multidisciplinary tertiary referral clinic should be planned.

Counselling about risk to fetus

The prognosis for the fetus under such circumstances would be poor. There would be a high risk of growth restriction and iatrogenic prematurity. There would also be a small risk of the fetus having a structural heart abnormality and, therefore, a fetal echo should be suggested.

Ethical question

IVF and Eisenmenger syndrome

A woman with Eisenmenger syndrome requests IVF. She is extremely intelligent, literate and rich. She feels that she is fully informed of the risks and is prepared to pay for any treatment. Would you agree to treat her? If not, on what grounds would you decline?

Write your thoughts in your reflective notes below

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Specific heart lesions

During pregnancy, at the time of delivery and in the immediate postpartum period the woman needs to be able to raise her cardiac output. The more severe heart lesions are those where the woman is unable to raise her cardiac output sufficiently, safely.

Severe heart lesions are therefore:

stenotic valves - particularly aortic and mitral. The increased cardiac output of pregnancy exacerbates the effect of any stenotic lesion (i.e. more blood trying to get through a tight hole)

poor ventricular function / reduced ejection fraction cyanotic heart disease ischaemic heart disease dilated aortic root - although the woman can raise her cardiac output she cannot do this safely,

as there is an increased risk of aortic dissection pulmonary vascular disease - Maternal mortality is highest with any form of pulmonary–

vascular disease

Rheumatic heart disease and mitral stenosis

These are discussed together because the most common cause of mitral stenosis is rheumatic heart disease, and the most common lesion caused by rheumatic fever is mitral stenosis.

Despite its decline in incidence, rheumatic heart disease is still an important problem in pregnancy, particularly if previously undiagnosed (as is often the case with recent immigrants). Rheumatic endocarditis is the most common cause of mitral stenosis in 75% of cases.

The normal mitral valve surface area is 4 cm2, but when the stenosis is severe (valve area2) approximately two-thirds of women will develop cardiac complications during pregnancy. In a triennial maternal mortality report (2003-5), mitral stenosis re-emerged as a cause of maternal deaths, accounting for two deaths, both in recently arrived immigrants to the UK.

Pregnancy is associated with a 40% increase in preload. This is illustrated in the animation below (click on the play buttons to view the animations).

View large version

The combination of impaired diastolic flow through the stenotic valve with pregnancy-induced tachycardia and increased stroke volume causes increasing left atrial pressure and may result in pulmonary oedema and dyspnoea. The woman is then further compromised if atrial fibrillation occurs.

In addition, the development of secondary pulmonary hypertension may result in right ventricular failure. The cornerstone of treatment is bed rest, diuretics, and rate control with β-blockade to allow left ventricular filling time. Heparin should be used for women with atrial arrhythmia, a dilated left atrium, and during bed rest.

In women with mitral stenosis, a diastolic murmur is heard over the apex. The major haemodynamic changes during the puerperium carry a particular risk of pulmonary oedema.

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Audio clip: Diastolic murmur heard over the apex as a result of mitral stenosis.

Management plan for a woman with mitral stenosis

Avoid tachycardia because:

it shortens ventricular filling time it increases right atrial pressure and the risk of pulmonary oedema

Treatment plan:

treat with beta blockers to slow the heart rate limit physical activity – care in labour with a short active second stage or elective forceps

delivery good analgesia vigilance regarding arrhythmias – treat and anticoagulate avoid syntometrine as this results in a rapid autotransfusion and can precipitate pulmonary

oedema

Avoid fluid overload:

care in labour – careful fluid management abrupt increase in preload at delivery may lead to an increase in right atrial pressure and

pulmonary oedema diuretics may have a role keep women 'on the dry side'

Aortic stenosis

Aortic stenosis is likely to be congenital in origin in women of childbearing age. Symptoms occur late and include chest pain, syncope and heart failure. Sudden death may occur. On examination, a loud, greater than 3/6, harsh systolic murmur can be heard.

The woman's preconception functional class provides a good estimate of the woman's ability to tolerate pregnancy. Women asymptomatic before conception will, in general, tolerate pregnancy, while those with symptoms or severe stenosis (valve area <0.5 cm2m–2, gradient >60 mmHg) are at risk of acute left ventricular failure. Women with severe stenosis do not tolerate hypotension or tachycardia well. Adequate preload (volume of blood in the ventricle) is needed to generate sufficient pressure in the ventricle to pump blood across the aortic valve. Blood loss, regional analgesia or vena caval compression can all compromise the woman's cardiac output.

The main objective is to avoid fluid depletion and hypotension. Early placement of an arterial line, maintenance of left uterine displacement and agressive treatment of blood loss are recommended. A bolus of intravenous oxytocin at delivery can cause severe intractable

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hypotension, and preplanning to avoid its use in these cases is prudent. An infusion of oxytocin for third-stage management reduces the risk of hypotension. If postpartum haemorrhage occurs, there should be early recourse to mechanical methods (bimanual compression) and misoprostol. If there is significant haemorrhage, resulting in hypotension, syntometrine can be used.

Aortic stenosis 2

Principles of management

Avoid hypotension:

fixed cardiac output tolerate a reduction in preload poorly beware of bleeding, spinals, postural hypotension always apply lateral tilt in the pregnant patient

View large version

The following animation shows (a) the effects of pre-eclampsia during pregnancy and (b) the effects of pre-eclampsia on a pregnant woman with aortic stenosis.

View large version

Valve problems

Regurgitant valves

Regurgitant valves are generally well tolerated in pregnancy as reduced systemic resistance encourages increased forward flow through the valve. It is difficult to estimate the ejection fraction accurately on echocardiogram if a valve is regurgitant, and echocardiogram estimations will tend to overestimate the gradient across a regurgitant valve.

Valve replacements

Prosthetic artificial valve – anticoagulation Prosthetic tissue – deteriorate with time

Women with mechanical prosthetic heart valves require lifelong anticoagulation, usually with warfarin, to prevent valve thrombosis. During pregnancy, their thrombotic risk increases (estimated as high as 29% with a 2.9% maternal mortality rate) and the need for effective anticoagulation is greater. Warfarin treatment throughout pregnancy appears to have the lowest risk of maternal thrombotic complications but is associated with a higher fetal loss rate and can have damaging effects on the fetus. The risk to the fetus appears to be lower when less than 5 mg warfarin per day is needed. Unfractionated heparin or low molecular weight heparin are safe for the fetus, but doubts have been expressed about their efficacy in preventing maternal thrombotic complications. Factors, such as the type and position of the mechanical valve, choice of anticoagulant regimen and patient compliance may all affect the rate of thrombosis.

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When tissue valves are used for valve replacements there is no need for long term anticoagulation, but the valve does deteriorate with time. Therefore, in a woman contemplating further pregnancies, a tissue valve is better than a mechanical prosthetic valve. Although it may subsequently need to be replaced, it will hopefully last until her family is complete.

Congenital lesions

Although congenital heart disease only accounts for a very small number of maternal deaths, more women with congenital heart disease are now surviving until their childbearing years and are the group of women most commonly seen antenatally in a joint obstetric cardiac clinic. Since this group of women are known to the healthcare services prior to pregnancy, there is an opportunity to offer preconceptual counselling.

At the time of booking for antenatal care, it is important to define the lesion and determine what surgery has been done previously. Women with surgically corrected congenital heart disease are still at risk, as there may be a residual defect.

A specific recommendation from the most recent maternal mortality report, Saving Mothers' Lives 06-08 is that, ‘Women with a known history of cardiac disease must be referred for consultant-led obstetric care in a maternity unit where there is a joint obstetric/cardiology clinic or a cardiologist with expertise in the care of women with heart disease in pregnancy.’.

Multidisciplinary care throughout the pregnancy and a clearly documented individualised plan of care for delivery and the immediate postpartum period is important.

Atrial septal defects Ventricular septal defects Patent ductusarteriosus Tetralogy of Fallot Fontan procedure Eisenmenger syndrome Marfan syndrome case scenario

Atrial septal defects

Atrial septal defects are usually well tolerated. If they are found prior to pregnancy it is sensible to consider closure prior to pregnancy in view of the risk of paradoxical embolism.

Ventricular septal defects

If the defect is less than 1.25 cm, pulmonary hypertension and heart failure are very unlikely to develop. Pregnancy is well tolerated in women with small or moderate ventricular septal defects (VSDs). If the VSD is found prior to pregnancy it is sensible to consider closure in view of the risk of paradoxical embolism and to prevent pulmonary hypertension developing.

Patent ductusarteriosus

Pregnancy is well tolerated in women with a patent ductusarteriosus (PDA) and a left- to- right shunt. In women with a clinically evident PDA, this should be closed prior to pregnancy.

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Tetralogy of Fallot

This is the most common form of cyanotic congenital heart disease.

The four features which make up the tetralogy of Fallotare :

ventricular septal defect pulmonary artery stenosis overriding aorta right ventricular hypertrophy.

Approximately 15% of women with tetralogy of Fallot have a deletion of chromosome 22q11. This increases the chance of the fetus also having congenital heart disease.

In women with an uncorrected tetralogy of Fallot, the right to left shunt worsens with pregnancy due to reduced systemic resistance. Cyanosis increases and this leads to increasing complications in pregnancy.

The most common situation encountered antenatally is where a woman has already had corrective surgery. Pregnancy is well tolerated in women who have had a repair of tetralogy of Fallot, as long as ventricular function is good and there is no significant right ventricular outflow tract obstruction. Many have significant pulmonary regurgitation and may become more tired and breathless as pregnancy progresses, occasionally needing diuretic treatment or admission for bed rest (Thorne 2004).

Thorne SA. Pregnancy in heart disease. Heart 2004;90:450–6.

Fontan procedure

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A Fontan procedure is a surgical operation that is required when the only way of correcting the heart is to change the circulation to a univentricular mode of circulation. Surgery is required in cases such as hypoplasticity of the right heart or tricuspid atresia. The systemic venous return is diverted directly to the pulmonary arteries and it does not go through the right ventricle. From the lungs, the blood comes back to the left side of the heart and the left side of the heart pumps it around the body and through the lungs. One ventricle is doing all the work, pumping the blood around the systemic and pulmonary circulations. In pregnancy, the single ventricle has to cope with the increased volume load. Women with a Fontan circulation can, therefore, have problems with heart failure in pregnancy.

The blood is flowing slowly by the time it gets to the lungs and there is an increased thrombotic risk. Often, women with Fontan circulations are anticoagulated. If the woman becomes hypotensive, blood pressure may be too insufficient to pump the blood through the lungs, and cyanosis may develop quickly.

Women who themselves have had a Fontan repair, have a 30% fetal loss rate in pregnancy.

Eisenmenger syndrome

View large version

Maternal outcome

The maternal mortality with Eisenmenger syndrome is 20–40%.

Fetal outcome

Cyanosis, low oxygen saturations and polycythaemia are associated with a poor fetal outcome.

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Maternal Sa02 (%) Chance of livebirth (%) Maternal Hb (g/dl) Chance of livebirth (%) >90 92 <16 71 85–90 45 17–19 45 <85 12 >20 8

Yentis SM, Steer PJ, Plaat F. Eisenmenger's syndrome in pregnancy: maternal and fetal mortality in the 1990s. Br J ObstetGynaecol 1998;105:921–2.

Management plan

Most of the maternal deaths associated with Eisenmenger syndrome occur in the puerperium. Women with Eisenmenger syndrome should be made aware of the significant risk that pregnancy poses to their life. They should receive good contraceptive advice and should know how to access termination of pregnancy services should an unexpected pregnancy occur.

The risk of maternal death in association with termination of pregnancy is still high at approximately 7%, but is less than the 30% maternal death rate if the pregnancy continues.

Marfan syndrome case scenario

A woman presents to an antenatal clinic and is known to have Marfan syndrome. She is at 12 weeks of gestation. On her last echocardiogram, her aortic root diameter was 3 cm.

In your reflective notes below, describe your proposed management.

Marfan syndrome case scenario - answer

From the previous page:

A woman presents to an antenatal clinic and is known to have Marfan syndrome. She is at 12 weeks of gestation. On her last echocardiogram, her aortic root diameter was 3 cm. Describe your proposed management.

Your answer should include the following information:

The main risk during pregnancy is the risk of aortic dissection. Cardiac output is higher and this increases the shear stress on the aortic root. The risk of aortic dissection is greater if the aortic root is greater than 4 cm in diameter and these women should be advised to have their aortic root repaired before embarking on pregnancy. Consider the diagnosis of aortic dissection in a woman with central chest pain or interscapular pain, particularly if there is a family history of this.

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Root diameter Risk of rupture

<4 cm 1%

>4 cm 10%

Women with Marfan syndrome should have regular echocardiography assessments during their pregnancy. Systolic blood pressure should be carefully controlled, and β-blockers are frequently used for this. Those with a rapidly increasing root diameter or an aortic root diameter greater than 4 cm should be delivered by elective lower-segment caesarean section.

Women with Ehlers–Danlos Type IV can dissect even with normal aortic root diameters. The time of highest risk is peripartum and early postpartum.

Marfan syndrome is autosomal dominant condition so there is a 1:2 chance of it being inherited by the child. A genetic referral and long-term follow-up should be arranged.

Dissection of the aorta in Marfan syndrome

Risk of congenital abnormality in the fetus

In women with congenital heart disease, there is an overall recurrence risk of congenital heart abnormality in the fetus in the order of 4%. In about half of these cases, the abnormality will be the same as that in the parent, and in half of the cases it will be a different abnormality. Fetal

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echo should be offered to all women where the mother (or father) of the baby has congenital heart disease.

22q11 deletion

Some women with congenital heart disease will have a deletion on the long arm (q arm) of chromosome 22. In these women there is a 1:2 chance of the fetus inheriting the deletion, and a 10% chance of congenital heart disease (not 50% because of variable expression).

Summary:

22q deletion 1:2 inheritance 10% chance of congenital heart disease.

Ischaemic heart disease

The incidence of ischaemic heart disease is increasing and it is becoming a more common cause of maternal mortality. It often occurs suddenly and unexpectedly in women with no previous history of heart disease. Approximately 20% of women with acute myocardial infarction die in pregnancy or within 1 week of delivery. An infarction occurring in the first two trimesters has a lower mortality than in the last trimester when the cause is often dissection of the coronary arteries or coronary thromboembolism, unassociated with atheroma.

Risk factors

Risk factors for ischaemic heart disease include:

multigravid smoking

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diabetes obesity hypertension hypercholestrolaemia

Coronary artery dissection

Although coronary artery dissection is rare in nonpregnant women, it is a recognised complication of pregnancy and the puerperium. It can lead to coronary artery occlusion and myocardial infarction. There should be a low threshold for angiography when myocardial infarction occurs in pregnancy or the puerperium, since demonstration of dissection allows the possibility of intervention.

Diagnosis

Ischaemia most commonly affects the anterior wall of the heart. Cardiac troponin I is unaffected by normal pregnancy, labour and delivery and, therefore, it is the investigation of choice in the diagnosis of acute coronary syndrome. Coronary artery angiogram, with the option of interventional therapeutic techniques, are the intervention of choice in pregnancy and postpartum.

Angiogram showing dissection of a coronary artery.

Treatment

Lipid-lowering drugs (statins), should be avoided in pregnancy as they are linked with congenital abnormalities. This is thought to be because the decreased synthesis of cholesterol affects fetal development.

Thorne SA. Pregnancy in heart disease. Heart 2004;90:450–6.

Clopidogrel inhibits platelet function and is antithrombogenic. Women with ischaemic heart disease may be taking clopidogrel when they become pregnant. There is too few data to know

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whether clopidogrel has a teratogenic effect. It is long-acting and can not be reversed so, therefore, women taking clopidogrel during pregnancy will have a bleeding tendency that can not be reversed.

Prophylaxis against bacterial endocarditis

Prophylaxis against bacterial endocarditis

NICE guidelines recommend that women at risk of infective endocarditis undergoing gynaecological and obstetric procedures do not require antibiotic prophylaxis regardless of the cardiac lesion.

National Institute of Health and Clinical Excellence. Antimicrobial prophylaxis against infective endocarditis in adults and children undergoing interventional procedures. Clinical guideline 64. London: NICE; 2008.

The strength of evidence on which this recommendation is based has been questioned.

Tower C, Nallapetta S, Vause S. Prophylaxis against infective endocarditis in obstetrics: new NICE guidance: a commentary. BJOG 2008;115:1601–4.

Cardiomyopathy

There are different types of cardiomyopathy:

peripartum dilated hypertrophic

Peripartum cardiomyopathy

Peripartum cardiomyopathy typically presents in a woman either when she approaches term or in the first few weeks postpartum; although it can occur up to five months postpartum. Whilst peripartum cardiomyopathy is more common in older women, black women, multiparous women and women suffering from obesity or hypertension, it can present in women with no risk factors who have previously been well. Unexplained breathlessness, tachycardia, gross oedema or supraventricular tachycardia should prompt echocardiography. There is a high recurrence risk in future pregnancies.

Dilated cardiomyopathy

If dilated cardiomyopathy is considered, anticoagulation should be instigated because a thrombus can form on the wall of the poorly contractile ventricle as shown in the picture below. This can then embolise. Pulmonary, peripheral and cerebral embolisation are major causes of maternal morbidity and mortality.

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Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HOCM) is an autosomal dominant condition that shows anticipation (gets worse in each subsequent generation). Usually pregnancy outcome is good unless there is severe diastolic dysfunction. Output may be compromised by:

bleeding – prevent/treat blood loss aggressively tachycardia – consider beta blockers to slow the heart rate, prolong diastole and allow

adequate ventricular filling vasodilatation – avoid nifedipine as a tocolytic and epidural analgesia arrhythmias – treat arrhythmia and consider anticoagulation

Heart failure

Treatment depends on the cause; however, there are some general principles:

Maternal health takes priority over fetal health In general, angiotensin-converting enzyme (ACE) inhibitors should be avoided in pregnancy as

they have teratogenic effects (cranial synostosis, heart defects) and can cause renal failure in the fetus/neonate. However, if maternal health is sufficiently compromised, the benefit to the mother may outweigh the risk to the fetus and support their use

ACE inhibitors can be used when breastfeeding Beta-blockers help control heart rate and can be used in pregnancy Frusemide can be used. It does not seem to cause salt or water depletion in the fetus but has

been associated with neonatal thrombocytopenia Digoxin may be used. It does cross the placenta but at therapeutic levels does not harm the

fetus If a woman has poor ventricular function consider prophylactic anticoagulation to avoid

intracardiac thrombus formation. During pregnancy low molecular weight heparin should be used. Warfarin can be used postnatally and can be used when breastfeeding

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Transplants

The following content is above core training level and included for information only.

The transplanted heart responds normally to pregnancy-induced changes. Complications are common during pregnancy:

almost half deliver 40% of women have maternal complications hypertension is very common fetal growth restriction is common LSCS delivery is required in approximately half of women 20% of women have rejection episodes in pregnancy 40% of women need to have the cyclosporin dose increased.

Arrhythmias

Women are often more aware of ectopic beats in pregnancy, and palpitations are a common symptom.

Important features to ask about in the history are:

frequency of episodes heart rhythm – is it regular or irregular? length of time for which the palpitations occur – occasional extra beats or a sustained run? associated syncope onset and offset – sudden onset and offset is more suggestive of arrhythmia underlying medical problems (e.g. thyrotoxicosis or heart disease).

Investigations

12-lead ECG (ideally when an episode occurs) Thyroid function tests Haemoglobin 24-hour ECG if palpitations are occurring sufficiently frequently to make this worthwhile Echocardiography and cardiology review for newly diagnosed arrhythmias in pregnancy to

determine whether there is an underlying cardiac problem.

Treatment

Reassurance is sufficient for majority of women Anticoagulation in women with atrial fibrillation Pharmacological treatment if associated with syncope or hypotension o β-blockers o Adenosine to terminate episodes of supraventricular tachycardia

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DC cardioversion if unresponsive to medical treatment.

Women with pacemakers should be reviewed during pregnancy by a cardiologist. Women with intracardiac defibrillators should have their device switched off in labour to avoid inappropriate shocks, and turned back on after delivery Women with inherited arrhythmias (e.g. long QT syndrome should be offered a consultation with a clinical geneticist to discuss follow-up and testing of the baby at an appropriate age).

Transposition of the great arteries

There are two different types of surgery that can be used to treat transposition of the great arteries. If a woman presents to you who has had one of these surgeries, it is important to know which one she underwent, since the types of complications seen vary between them.

Atrial switch procedures (Mustard or Senning procedure)

Following this operation, the right ventricle supplies the systemic circulation and the left ventricle supplies the lungs. With the increased cardiac output in pregnancy, right (systemic) ventricular function may decline.

Arterial switch procedures

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In this operation, the great arteries are switched round so that the left ventricle supplies the systemic circulation, and the right ventricle the pulmonary circulation. This operation is a newer treatment; therefore, women tend to be younger, and there are fewer data about possible complications in pregnancy.

Final assessment

An 18-year-old woman who is currently 14 weeks pregnant is referred to ANC with a heart murmur. This was found by her GP when she attended the GP surgery with hyperemesis gravidarum a few weeks ago. She is otherwise fit and healthy. There is no history of chest pain, breathlessness, palpitation, cough or syncope. There is no medical or surgical history of note. She smokes five to eight cigarettes a day. Currently, she is not on any medications.

On examination:

BMI: 20 pulse: 76 bpm and regular blood pressure: 100/52 mmHg.

On auscultation her chest is clear with normal heart sounds and a soft ejection systolic murmur is heard over the pulmonary area. There is no evidence of peripheral oedema.

You feel this is most likely a flow murmur caused by the cardiovascular changes of pregnancy.

Which of the following statement is most appropriate regarding cardiovascular changes in pregnancy?

Increased preload, increased afterload, increased cardiac output by 20% by 8 weeks of gestation, increased serum colloid osmotic pressure by 10-15%.

Increased preload, decreased afterload, increased cardiac output by 40% by 8 weeks of gestation, decreased serum colloid osmotic pressure by 20-30%.

Increased preload, decreased afterload, increased cardiac output by 20% by 8 weeks of gestation, decreased serum colloid osmotic pressure by 10-15%.

Decreased preload, increased afterload, increased cardiac output by 40% by 8 weeks of gestation, increased serum colloid osmotic pressure by 10-15%.

Decreased preload, decreased afterload, increased cardiac output by 20% by 8 weeks of gestation, decreased serum colloid osmotic pressure by 20-30%.

Correct

The correct answer is increased preload (as increased plasma volume), decreased afterload (as reduced systemic vascular resistance by 25–30% due to peripheral vasodilatation), increased

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cardiac output by 20% by 8 weeks of gestation (increased CO by 40% during pregnancy) decreased serum colloid osmotic pressure by 10–15%.

You have reviewed a 38-year-old woman in the labour suite who is currently 40 weeks into her second pregnancy. She had uncomplicated vaginal delivery at term 4 years ago.

She has presented with worsening breathlessness and palpitations over the last few days. She also mentioned requiring four pillows to sleep at night. She denied any chest pain, cough or syncope. There is no past cardiac or respiratory history of note. On examination:

BMI: 35 pulse: 134 bpm and regular blood pressure: 130/78 mmHg respiratory rate: 28 breaths per minute SpO2 on air: 94% chest clear normal first and second heart sounds with gallop rhythm mild-to-moderate peripheral oedema.

ECG shows sinus tachycardia and chest x-ray shows an enlarged heart with pulmonary congestion. Her arterial blood gas is normal. She has been reviewed by the cardiologist and had an urgent echocardiogram, which is suggestive of peripartum cardiomyopathy.

Which of the following statement regarding peripartum cardiomyopathy is correct?

Thromboprophylaxis should be considered if there are arrhythmias

Risk factors include advanced maternal age, Afrocaribbean race, primiparous women, multiple pregnancy and hypertension

Maternal mortality rate is approximately 40%

It occurs between the last month of pregnancy and the first 5 weeks postpartum

Cardiac transplantation is inappropriate Correct

The correct answer is thromboprophylaxis should be considered if there are arrhythmias. It should be considered if there are arrhythmias, intracardiac thrombus or severely impaired left ventricular dysfunction to minimize the risk of peripheral embolism, including cerebral embolism.

The other possible answers are incorrect because:

cardiac transplantation may be the only option in severe cases unresponsive to conventional and full supportive management

it occurs between the last month of pregnancy and the first 5 months postpartum

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recent study suggests maternal mortality rate is approximately 9–15% risk factors include increase maternal age, Afrocaribbean race, multiparous women, multiple

pregnancy and hypertension

You are asked to review a 25-year-old woman in the antenatal clinic who is known to have Marfan syndrome. She is currently at 12 weeks of gestation in her first pregnancy. At 15 years of age, she suffered from dislocation of the lens (right eye). She has never had any cardiac symptoms and her aortic root diameter was 3.9 cm on her last echocardiogram (2 months ago). She has no other medical or surgical history of note. Currently, she is not on any medications. Her father and her uncle died of aortic dissection.

On examination:

BMI: 22 pulse: 60 bpm and regular blood pressure: 110/50 mmHg chest clear with normal heart sounds.

Which of the following statements is most appropriate in her case regarding pregnancy outcome and management?

There is a 25% chance the baby will have Marfan syndrome

She has an increased risk of aortic dissection during pregnancy and 6 weeks postpartum

Regular echocardiograms may be required if she becomes symptomatic during pregnancy

Elective caesarean section will be indicated for obstetric reasons only

Consider starting β-blockers if no other contraindications Correct

The correct answer is elective caesarean section is indicated only for obstetric reasons. Elective caesarean section is recommended for women with aortic roots showing progressive enlargement or with a diamter>4.5 cm. Caesarean delivery may also be considered in patients with aortic root diameter between 4 and 4.5 cm, based on the individual situation.

The other possible answers are incorrect because:

β-blockers have been shown to slow the rate of aortic dilation and reduce the risk of dissection. They should be continued or started in pregnant patients with aortic dilatation or hypertension

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regular echocardiograms should be performed to assess aortic root diameter she has got an increased risk of aortic dissection during pregnancy and

6 months postpartum there is 50% chance the baby will have Marfan syndrome (autosomal dominant).

A 40-year-old woman presents to the emergency department with acute chest pain. She is 28 weeks pregnant with IVF twins. She has a BMI of 40. You suspect a myocardial infarction.

Which of the following ECG changes will most support your diagnosis?

ST elevation

Q wave in lead III

Infero-lateral T wave inversion

Right bundle branch block

ST depression Correct

The correct answer is ST elevation. The remaining features can all be found on a normal pregnant ECG. Right bundle branch block can be a normal ECG feature in young women. New onset symmetrical T wave inversion can be a sign of MI as can new development of Q waves. Serial ECGs may be useful in diagnosis and changes may develop. Troponin is not increased above the upper limit of normal in healthy pregnant women (though can be raised in PET, gestational hypertension and PE).

You are asked to review a 22-year-old woman who is known to have mitral stenosis. She is currently at 12 weeks of gestation in her first pregnancy. She has had percutaneous mitral commisurotomy in the past. Currently she is asymptomatic and is not on any medications. There is no other medical or surgical history of note.

On examination:

BMI = 22 Pulse = 60 beats/minute and regular BP = 110/50 mm Hg Chest = clear; loud heart sounds with diastolic murmur over mitral area

Recent echocardiogram showed moderate mitral stenosis with a large left atrium.

Which of the following statement is most appropriate regarding her management during pregnancy?

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Multidisciplinary team input, avoid tachycardia, monthly or bimonthly echocardiography depending on haemodynamic tolerance

Multidisciplinary team input, avoid tachycardia, monthly or bimonthly echocardiography depending on haemodynamic tolerance, anticoagulation

Multidisciplinary team input, perform planned percutaneous mitral commisurotomy before 20 weeks of gestation, monthly or bimonthly echocardiography depending on haemodynamic tolerance, anticoagulation

Multidisciplinary team input, bed rest, oxygen therapy, monthly or bimonthly echocardiography depending on haemodynamic tolerance, anticoagulation

Multidisciplinary team input, avoid bradycardia, monthly or bimonthly echocardiography depending on haemodynamic tolerance, anticoagulation

Correct

The correct answer is multidisciplinary team input, avoid tachycardia, monthly or bimonthly echocardiography depending on haemodynamic tolerance, anticoagulation.

This is a high risk pregnancy and the woman should be reviewed by the multidisciplinary team (obstetrician, cardiologist, anaesthetist). Bed rest and oxygen therapy is not routinely recommended. When symptoms or pulmonary hypertension (echocardiographically estimated systolic PAP >50 mmHg) develop, activity should be restricted and β1-selective blockers commenced. Diuretics may be used if symptoms persist, avoiding high doses.

Clinical and echocardiographic follow-up is indicated monthly or bimonthly depending on haemodynamic tolerance. In mild MS, evaluation is recommended every trimester and prior to delivery.

Percutaneous mitral commisurotomy is preferably performed after 20 weeks of gestation. It should only be considered in women with NYHA class III/IV and/or estimated systolic PAP >50 mmHg at echocardiography despite optimal medical treatment, in the absence of contraindications and if patient characteristics are suitable.

Tachycardia is particularly dangerous in mitral stenosis as it results in pulmonary oedema. Tachycardia → further decrease in diastolic filling of left ventricle → fall in stroke volume → rise in left atrial pressure → pulmonary oedema.

Therapeutic anticoagulation is recommended in the case of paroxysmal or permanent AF, left atrial thrombosis, or prior embolism. It should also be considered in women with moderate or severe MS and spontaneous echocardiographic contrast in the left atrium, large left atrium (≥40 ml/m2), low CO, or congestive heart failure, because these women are at very high thrombo-embolic risk.

Mrs Parker is a 20-year-old woman who attended the obstetric cardiology clinic with her partner for pre-pregnancy counselling. She has a repaired Tetralogy of Fallot (ToF) and is

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contemplating her first pregnancy. She is asymptomatic and her recent echocardiogram showed mild pulmonary regurgitation.

Which of the following statement is most appropriate regarding her management during pregnancy?

Will require a fetal cardiac scan as the overall risk of the fetus having a congenital heart disease is 25%

Monthly or bimonthly cardiac evaluation with echocardiography is indicated

May develop arrhythmias and left heart failure

Likely to tolerate pregnancy well

A planned caesarean section at term is recommended Correct

The correct answer is likely to tolerate pregnancy well.

The preferred mode of delivery is vaginal in almost all cases. Caesarean section is only indicated for obstetric reasons

Women with repaired Tetralogy of Fallot usually tolerate pregnancy well (WHO risk class II). Cardiac complications during pregnancy have been reported in up to 12% of patients

Arrhythmias and right heart failure in particular may occur. Moderate to severe pulmonary regurgitation → increase in RV size → RV dysfunction and failure. If RV failure occurs during pregnancy, treatment with diuretics should be started and bed rest advised. Transcatheter valve implantation or early delivery should be considered in those who do not respond to conservative treatment

Follow-up every trimester is sufficient in the majority of women. In women with severe pulmonary regurgitation, monthly or bimonthly cardiac evaluation with echocardiography is indicated

The woman will definitely require a fetal cardiac scan but the overall risk of the fetus having a congenital heart disease is 2–5%.

mother with CHD = 6% risk father with CHD = 2% risk one previous child with CHD = 2–5% two previous children with CHD = 10–15% The level of risk also depends on the specific lesion and the risk is highest (1 –20%) for

congenital aortic stenosis.

Cardiac disease Introduction to cardiac disease

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