| Dr.Manal madany
Heart disease in pregnancy
Normal hemodynamic changes during pregnancy:
1. Blood volume increases by 30%.
2. Plasma volume increases by 50%.
3. Red cell mass increases by 18% when no iron supplement is given and by 36% when iron supplement is given.
4. Hemodilution anaemia due to increased plasma vol. greater than red cell mass.
5. COP (cardiac output) increases by 40% starts at 5 weeks reaches maximum at 24-28wks & remains elevated till parturition, this increase in C.O.P is mainly due to increase in stroke volume and to lesser extent to increase in H. rate
6. Increase in H. rate by 10-15 beats/min
7. Decrease in PVR (peripheral vascular resistance) & decrease in pulmonary vascular Resistance & decrease in colloid oncotic pressure
8. Supine hypotension due to pressure of gravid uterus on the main vessels.
9. Central venous pressure is the same as non pregnant.
10. The decrease in PVR will decrease the mean & diastolic blood pressure which is clearly observed in the second trimester.
1l. B.P (systolic & diastolic) falls throughout the first 2 trimesters reaching a nadir (lowest point) 24-28w before increasing to non pregnant levels at term.
Physiological changes during labour and puerperium.
1. First stage.
Cardiac output increases by15%. Uterine contractions increases venous return, causing increase in cardiac output & can cause reflex bradycardia.
2. Second stage
Increase in intra abdominal pressure (valsalva’s) causes increase in venous return and cardiac output.
3. Third stage
Normal blood loss during delivery
(Around 250-350 ml). It leads to
a. Decrease blood volume
b. Decrease cardiac output.
After delivery, cardiac output increases again immediately : 60-80%
sudden interruption of placental circulation
relief of caval compression
within 1 h: rapid decline to pre-labour values
retented Interstitial fluid returned to circulation
return to normal after 2 weeks
The greatest change period in systemic blood circulation and heart burden & Easily induced heart failure
32 - 34 weeks
3 days postpartum
Heart disease in pregnancy is rare, but potentially serious & complicates approximately 1% of all pregnancies.
In UK 50 years ago, rheumatic heart disease account for 90% of all heart disease in pregnancy but since the wide use of Antibiotic in streptococcal infection this figure has fallen dramatically.
Congenital heart disease now account for 50% of H. disease in pregnant women in the UK (because the advanced in pediatric surgery—increase number of women with cong. heart disease surviving to reach child bearing age.
Acquired IHD (ischemic heart disease) is becoming more common in pregnancy related to delay in average age of child bearing & the epidemic of smoking amongst women
To understand the effects of heart disease on the pregnancy it is necessary to know the hemodynamic changes during pregnancy, it becomes clinically evident only when fail to compensate or has adverse affect on the health of patient.
New York heart association (NYHA) functional classification:
Class I: no functional limitation-------- symptoms with extraordinary
Class II: mild limitation of activity-------symptoms with ordinary physical
Class III: marked limitation of activity------symptoms with less than
Class IV: severe limitation of activity-------- symptoms at rest
Although maternal mortality is seen with all forms of heart disease, it is mostly likely in conditions restricted an increase in pulmonary blood flow typically pulmonary hypertension & mitral valve stenosis.
(40-50%) pulmonary hypertension & Eisenmenger's syndrome.
(5%) Fallots tetralogy (because there is no pulm. Hypertension).
Other common causes of maternal death are: cardiomyopathy, rupture or dissection of the aorta, IHD (ischemic heart disease).
Infective endocarditis is rare as routine antibiotics are used.
Risk factors that predict maternal morbidity:
1. Prior episodes of arrhythmia, heart failure or stroke
2. Severe impairment of left ventricular function or sever left heart obstruction from aortic stenosis or hypertrophic cardiomyopathy (HOCM)
3. Pre pregnancy NYHA class III or IV
4. Ejection fraction < 40%
5. Others (Congestive heart failure, acute pulmonary edema and thrombo-embolic complications).
The fetus is at increase risk of IUGR & preterm delivery in pregnancy Complicated by cyanotic cong. heart disease when total fetal loss may reach 40%
Uncorrected coarctation of aorta with IUGR by > 10% due to reduced placental perfusion
Incidence of congenital heart disease in new born baby is 5% if a parent is affected compared to 8 in l000 live births general population, so detailed anomaly scan is mandatory with echo study at 24 weeks gestation.
Most women with heart disease will be aware of their problem prior to pregnancy; she should be fully assessed before being pregnant.
Maternal & fetal risks carefully explained.
Cardiologist should be involved including cardiac echo.
Any concurrent medical problems should be aggressively treated
If surgical correction is needed, it should be done before pregnancy.
Issues in pre-pregnancy Counseling:
Risk of maternal dearth
Possible reduction of maternal life expectancy.
risk of fetus developing cong. Heart disease
risk of preterm labor &IUGR
Need for frequent hospital attendance & possible admission
Contraindications of pregnancy are:
Eisenmenger's syndrome, severe MS, marfan's syndrome with aortic root dilatation and severe cardiomyopathy.
It should be a combined care (obstetric / cardiac clinic), clinical evaluation by: 1.History: Easy fatigability, SOB, orthopnea, pulmonary congestion (these are S&S of left sided H. failure), weight gain, dependent edema, hepatomegaly (these are S&S of right sided H. failure). Past hx: previous obstetric complications like stillbirth, IUGR, babies with congenital heart disease and hx of heart surgery
2.Physical examination: P.R & Rhythm, B. pressure, JVP, presence of basal crepitation, ankle and sacral oedema, symphysis fundal height measurement.
3.Risk factors for the development of heart failure:
RT.I (respiratory tract infection), Anaemia, obesity, corticosteroid, tocolytics, multiple gestation, hypertension, arrhythmia, pain related stress, fluid overload
4.Advice during each AN visit:
- Bed rest increases the venous return, improves renal function, induces diuresis, decreases the metabolic needs of several organs especially the muscles.
- Dietary salt restriction to prevent excessive sodium & water retention
- Prevention & treatment of anaemia
- Rx of any infection especially R.T.I
- Adequate dental care (tooth extraction under cover of antibiotics).
- Anticoagulant therapy indicated in patients with congenital heart disease having pulmonary hypertension, artificial valve replacement and in those with atrial fibrillation. Using heparin throughout the pregnancy or warfarin and replace it with heparin in the 1st trimester and prior to planned delivery.
5. Hospital admission: For assessment and treatment
It is urgent if there has been deterioration in the patient condition or any acute complication has arisen.
Admit the patient for rest & assessment for a few days before term.
Admission to the hospital should not mean complete immobilization unless the patient condition is very serious
Physiotherapy & ambulation with assistance with possible use of anti coagulant therapy to protect against the danger of DVT & pulmonary embolism.
Serial US every 2-4 wks in the 3rd trimester allow assessment of fetal growth and regular cardiotocography, if IUGR premature delivery may be indicated.
6. Medical treatment: specific treatment may be required if there are complications related to the patient cardiac condition
Disorder of rhythm may necessitate the use of digoxin, infection should be vigorously treated with antibiotics, pulmonary oedema or cardiac failure requires immediate admission & prompt treatment.
Sitting up helps the patient to breath more easily
morphine or its derivatives relieves anxiety & reduces the increased respiratory rate
SVT treated by vagal pressure, adenosine or IV verapamil
Digoxin is beneficial if there is marked tachycardia or fibrillation
Diuretics e.g. frusemide in a dose 50-100mg I.V.
7. Surgical treatment:
Corrective cardiac surgery is best performed before the patient become pregnant. Occasionally patent ductus arteriosus is ligated during pregnancy because of sever degree of left to Right shunt. The closure of VSD, ASD should not be done during pregnancy. Some time in MS (mitral stenosis) in severe symptomatic case balloon valvotomy is carried out during pregnancy.
Management of labor:
1. Avoid induction of labor if possible, wait for spontaneous onset to minimize the intervention and enhance the success; however induction may be indicated in certain cases before circulatory crisis develops.
2. Ensure fluid balance.
3. Avoid supine position, the most comfortable position that make breathing easier should be adopted.
4. Effective pain relief, discuss regional /epidural anesthesia with senior anesthetist with the potential risk of hypotension.
5. Keep second stage short, forceps or vaccum can be used.
6. Use syntocinon insidiously, ergometrine is contraindicated.
7. Antibiotics prophylaxis may be indicated to prevent infective endocarditis in those with high risk for IE (such as women with previous IE) or those who may have the poorest outcome (such as those with cyanotic heart disease) using amoxicillin 2gm iv plus gentamicin 120mg at the onset of labour, ruptured membranes or prior to caesarean section, followed by amoxicillin 500mg orally 6 hrs later, if allergy to amoxicillin vancomycin 1gm iv may be used.
8. O2 must be available & should be given if there is dyspnea or cyanosis.
9. Cardiac disease is not an indication for CS but if there are obstetric complications, operation is not contraindicated
10. Dehydration, metabolic acidosis & infection of genital tract are always should be avoided
The need for rest doesn't mean complete rest.
Active movement in bed with regular exercise
The possibility of anticoagulant therapy must be considered (Prophylactic antibiotics may be indicated)
Sterilization may be recommended by cardiologist if acceptable to the patient can be done by laparoscopy 6 weeks postpartum.
Some encouragement to limit family size, family be completed at younger age and before there is sever deterioration in cardiac function, at same time optimal spacing of birth will ensure that no more than one child at time must be nursed, lifted & carried
Oral contraception & condoms are probably preferable to insertion of intrauterine contraceptive device.
Termination of pregnancy:
May be considered in a patient with grade III & IV, patient had history of H. failure in previous pregnancy and patient with Eisenmenger's syndrome and pulm. hypertension, it should be considered early in pregnancy because after 14ws,the risk of termination is probably at least equal to that of well managed pregnancy.
Special heart conditions occurring during pregnancy:
Is the commonest acquired heart disease account for 90% of Rheumatic valvular problems.
The stenosis (left atrial obstruction) increases left atrial & pulmonary wedge pressure (pulm. oedema & atrial fibrillation may occur), there is fixed C.O.P with limited ability to adopt to increase demands placed on the heart during pregnancy by increase intra-vascular volume & heart rate.
These patients at risk of developing:
Congestive heart failure.
Acute pulmonary edema.
Subacute bacterial endocarditis.
Increase risk IUGR and fetal damage.
Prepregnancy care: cardiac echo & cardiologist involvement. In sever stenosis surgical correction should be taken before conception.
During pregnancy: In addition to the usual care beta blockers may be used to control maternal tachycardia, atrial fibrillation treated by digoxin or cardioversion, sometimes in sever symptomatic cases surgery (balloon valvotomy during preg.)