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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?