Cardiac Diseases in Pregnancy

Dr. Harris N Suharjono2013

Content of lecture: Significance of heart disease in pregnancy?

Physiology adaptation

Preconception care.

Antenatal care with cardiac problem

Specific heart problems

Anticoagulation therapy

General advice for Medical Officers

How significant is heart disease in pregnancy? Accounts for 12% of maternal death in

1996. Commonest cause of indirect maternal

death in Malaysia In Sarawak there were a total of 9

maternal deaths from heart diseases in the 3 years period between 2010-2012

How common?

Coronary artery disease is uncommon in pre-menopausal women of child-bearing age. Majority of cardiac conditions encountered during pregnancy will be either congenital heart disease or rheumatic valvular heart disease.Cardiac complications result from hemodynamic changes that occur during pregnancy.

CVS adaptation to pregnancy

Cardiac output Increased by 45%

Stroke volume increased

Heart rate Increase by10-20 bpm

Blood pressure Reduced in the 1st & 2nd trimester.

CVP static

SVR & PVR Reduced 25-30%

sr,.colloid oncotic pressure

Reduced 10-15%

FIGURE 1 Plasma volume and red blood cell (RBC) increase during the trimesters of pregnancy. The plasma volume increases to approximately 50% above baseline by the second trimester and then virtually plateaus until delivery.

FIGURE 2 Hemodynamic changes during pregnancy relate to increased cardiac output and a fall in peripheral resistance. Blood pressure in most patients remains the same or falls slightly. Venous pressure in the legs increases, causing pedal edema in many patients.

Misleading features during pregnancy:Dyspnoea and tachycardiaDisplacement of apex beatBounding/collapsing pulseThird heart sound, ejection systolic

murrmur, ectopics,

Misleading features during pregnancy:ECG:EctopicsQ-wave and inverted T ,ST-depression,QRS axis left shift.CXR:Increased pulmonary vascular markingSlight cardiomegaly

Preconception counselling: Counseling plays an important role!!! Should be referred by cardiologist or

physician to the PPC Clinic, if the patient is keen to embark on a pregnancy

Estimate the risk during pregnancy Any optimization needed? Contraception necessary if advised not to

conceive

Contraception:Surgical: vasectomy BTL

-Best, low failure rate (LFR)-Laparoscopic/minilap

Barrier method: condom, spermicides

Compliance issues,High failure rate (HFR).

COCP:

POP: /Implanon NXT

Avoid in IHD, valvular heart disease and Pulmonary hypertensionVery useful

IUCD/LNG-IUS (Mirena)

LFR, contraindicated in prosthatic valve, endocarditis.

High Risk Heart DiseasesWomen with the following conditions are usually advised to avoid pregnancy.Pulmonary hypertension (>60% systemic pressure) Dilated cardiomyopathy, ejection fraction <40%Symptomatic obstructive lesions (delay pregnancy until the obstruction has been corrected)

Aortic stenosis Mitral stenosis Pulmonary stenosis Coarctation of the aorta

Marfan syndrome with aortic root >40 mm diameterCyanotic lesions 

Indicators of heart disease:Symptoms: Dypsnoea Orthopnea PND Haemoptysis Syncope Chest pain

Signs:CyanosisClubbingPersistent neck vein distensionLoud diastolic murmurCardiomegalyArrythmia

Consider termination if: Pulmonary hypertension Eisenmenger syndrome. Cyanotic heart disease. LVEF <40% Marfan Syndrome with aortic root more

than 4cm.

Risk categorisation:Low Risk:ASD VSDPDAMS

Mod-High Risk:MS with AFArtificial valveCOAPrevious MI

Antenatal care: Combined clinic Precipitating factor of heart failure Watch out for dangerous periods Dental care Rest/ diet/ smoke Contraception Planning of delivery (mode) always get

anesthetic review/opinion Multidisciplinary Team approach maybe

necessary in high risk patients COMPLIANCE to follow up is important

CVS drugs safety profile in pregnancy:

Beta-blockers safeDigoxin safeDiuretics Use judiciouslyAce-i unsafeCalcium antagonist Use judiciouslyAdenosine safeLidocaine safeProcainamide safeQuinidine SafeAmiodarone unsafe

Mode of Delivery For most patients, vaginal delivery feasible and preferable. Caesarean section indicated only for obstetric reasons, except the following.

o Patient anticoagulated with warfarin o Patient with dilated unstable aorta (e.g., Marfan syndrome) o Severe pulmonary hypertension o Severe obstructive lesion such as aortic stenosis

High-risk patients should be delivered in center with expertise to monitor hemodynamic changes and intervene when necessary.

No consensus regarding antibiotic prophylaxis at time of delivery, but many institutions routinely give.

Hemodynamic changes during labour and delivery

Hemodynamic changes often abrupt. With uterine contraction, up to 500 mL of blood may be released into circulation, causing

rapid increase in cardiac output and blood pressure. Cardiac output often 50% above baseline during 2nd stage of labour and may be even

higher at time of delivery. During normal vaginal delivery, about 400 ml of blood is lost. With caesarean section, about 800 ml of blood is lost. After delivery of baby, abrupt increase in venous return (autotransfusion from uterus &

baby no longer compresses inferior vena cava). Autotransfusion of blood continues for up to 24 to 72 hours after delivery, and this is

when pulmonary oedema may occur.

Intra-partum: Delivery in specialist hospitals Fluid management important Lateral position if symptmatic Ensure good analgesia Oxygen maybe necessary CCU maybe required post delivery Use syntocinon and avoid syntometrine Shortened second stage in some cases

Intra-partum: IOL and Mode of delivery generally follow

obstetric indication SBE prophylaxis: IV Ampicillin 1 g & gentamicin 1.5 mg/Kg (max 120mg) followed by ampicillin 500mg 6 hourly till delivery. If allergic to penicillin: IV vancomycin1g

over 2 hours. SBE prophylaxis only necessary in some

cases

Postpartum: HIGH RISK period!!!! CCU care Counseling for contraception needs Encourage to limit number of pregnancy

and BTL Breast feeding not contraindicated. High Risk E-discharge and home visits

compulsory PPC clinic appointment if still keen on future

pregnancy Family planning clinic appointment

(encourage BTL)

Specific conditions: Atrial fibrillation (AF) Valvular heart disease Mitral stenosis Mitral regurgitation Aortic stenosis Aortic regurgitation

Atrial Fibrillation Usually associated with another underlying

cause, such as mitral stenosis, congenital heart disease, or hyperthyroidism.

Antithrombotic therapy recommended. Use heparin in 1st trimester and last month of

pregnancy. Subcutaneous unfractionated heparin 10,000 to 20,000 units every 12 hours, adjusted to achieve APTT 1.5-2.0 times control.

Use oral anticoagulant during 2nd trimester. Target INR 2.0-3.0.

Control ventricular rate with digoxin, calcium channel antagonist, or beta blocker.

Valvular heart Disease Most can be managed with conservative

medical measures. Symptomatic or severe valvular lesions

should be rectified before conception and pregnancy whenever possible.

Drugs should be avoided when possible.

Mitral Stenosis Mild to moderate mitral stenosis can be

managed with diuretics and cardio selective beta blockers.

Severe mitral stenosis should undergo PTMC before conception, if possible.

PTMC recommended if develop severe symptoms during pregnancy.

Mitral Regurgitation Can usually be managed medically with

diuretics. If surgery is required, repair is

preferred.

Aortic Stenosis Mild stenosis and normal left ventricular

systolic function can be managed conservatively.

Moderate to severe stenosis or symptomatic, delay conception until aortic stenosis is corrected.

Pregnant women with severe aortic stenosis who develop symptoms may require either early delivery or percutaneous balloon valvotomy or surgery before delivery.

Aortic Regurgitation Isolated aortic regurgitation can be

managed with diuretics and vasodilator therapy.

Surgery during pregnancy only for control of refractory symptoms.

Anticoagulation therapy Low molecular weight heparin

(LMWH) and Factor Xa inhibitors should not be used in pregnancy unless Factor Xa activity can be measured

The anticoagulation therapy for patients with mechanical valves is of critically important and should be managed by Cardiologists

Anticoagulation: 1st trimester If warfarin maintenance dose is ≥5

mg/day, risk of teratogenicity is 8-10%. Convert warfarin to subcutaneous unfractionated heparin (UFH) b.d. Maintain APTT 1.5-2X control.

If warfarin dose is <5 mg/day, risk of teratogenicity is 2%. Discuss risks with patient and the options of changing to UFH or continuing warfarin.

Anticoagulation: 2nd & 3rd trimester Use warfarin. Maintain INR 2.0-3.0. At 36 weeks, admit patient and convert

to i.v. UFH. Plan for delivery once INR <1.5.

Stop i.v. UFH 6 hours before delivery and restart 6 hours after delivery if no bleeding.

First dose of warfarin can be given Day 1 post-partum. Stop i.v. heparin once INR >1.8.

Shared care: It’s important to maintain good

communication between the Cardiologists/Physicians and the Obstetrician

These patients should be f/up in a combine clinic setting but shared care with health clinics is possible depending on the severity of cases

General Advice for MOs1. If a pregnant woman is suspected or known to have heart disease, she should be referred

to a physician or cardiologist as soon as she is found to be pregnant. In the referral letter, request the specialist to state clearly in his/her reply letter:

a. The cardiac diagnosis b. Whether the pregnancy is allowed to continue or whether termination is

recommended c. The type of antenatal follow up required – polyclinic, district hospital, hospital

with specialist or cardiac centre 2. If unsure, always check the drug formulary (MIMS, MOH “blue book”, internet

resources, etc) to confirm that whatever medication prescribed is safe to use during pregnancy.

3. The best guide to how well a patient with heart disease is tolerating pregnancy is her functional status. If the patient is asymptomatic and able to do moderate or heavy work without any difficulty, then most likely she will also tolerate the pregnancy.

4. Physical examination should be geared towards looking for signs of heart failure – basal lung crackles, raised JVP, peripheral edema.

Multiple repeat echocardiograms usually not necessary as the cardiac lesions are “fixed” and unlikely to change during the course of the pregnancy

Think: What can you do to reduce the morbidity and mortality of pregnant mothers with heart diseases?