Heart diseases in pregnancy

Cardiovascular changes during pregnancy:

intravascular volume and cardiac output increase by 50%

Decrease in peripheral vascular resistance and blood pressure (endothelium dependent factors)

Physiologic high output (HR 10-20 bpm and ejection fraction – early increase in ventricular wall muscle mass, increased end- diastolic volume, heart is phisiologicly dilatated and has higher contractility))

Peak during the second trimester (20-28)

The increased blood volume serves two purposes. First, it facilitates maternal and fetal exchanges of respiratory gases, nutrients and metabolites. Second, it reduces the impact of maternal blood loss at delivery. Typical losses of 300-500 ml for vaginal births and 750-1000 ml for Caesarean sections are thus compensated with the so-called "autotransfusion" of blood from the contracting uterus

Aortocaval Compression - enlarged uterus compresses both the inferior vena cava and the lower aorta when the patient lies supine cousing reducton in return to the heart and cosequent fall in stroke volume and cardiac output (up to 25 %). Pregnant woment should lie on the side or the pelvis should be rotated - so the uterus drops on the side.

Reduced cardiac uotput is associated with reduction in uterine blood flow, and lower placental perfusion = deceleration in FHR on CTG

Pulmonary vascular resistance like systemic vascular resistance in diminished

PCWP – pulomary capillary wedge pressure is the same, but colloid oncotic pressure is reduced - making pregnant women susceptible to pulmonary oedema

(espessialy if there is increse in cardiac pre- load - i.v. Fluides or increased in pulomnary capillary permeability - preeclampsia)

LABOUR: Futher increase in cardiac uotput ( 15% in the first stage

and 50 % in the second stage) Uterine contractions lead to autotransfusion of 300 – 500

ml of blood into circulation Sympathetic response to pain and anxiety elevates futher

HR and blood pressure After delivery there is immediate rise in cardiac output –

relife of IVC and contracting uterus empties the blood to systemic circulation

Women with cardiovascular disease are most at risk of pulmonary oedema during second satge of labour and immediate postpartum period

Cardiac output returns to normal in 2 weeks.

Symptoms mimicking cardiac disease in healthy pregnant women: fatigue, dyspnea, light-headedness

„Abnormal” cardiac findings in pregnancy: displaced apical impulse, prominent jugular venous pulsations, widely split I and II heart sounds, soft ejection systolic murmur

ECG findings: sinus tachycardia, premature atrial/ ventricular ectopic beats, right/left axis deviation, ST-segment depression, T-wave changes

Echocardiographic findings

Mild increase in left ventricular diastolic dimension with preservation of ejection fraction

Functional tricuspid and mitral regurgitation

Small pericardial effusion

Pathology

Outcomes vary with different cardiac lesions

Ability to tolerate pregnancy depends on : Precence of pulmonary hypertention Functional class – NYHA Heamodynamic significance of any lesion Presence of cyyanosis (arterial oxygen sauration < 80%) High risk of death during pregnancy: Eisenmenger

syndrome, pulmonary vascular obstructive disease, Marfan syndrome with aortopathy, mitral stenosis( pulmonary oedema)

Other complications: heart failure, arrythmias, stroke Fetal complications: spontaneus abortion, premature

birth, IUGR, low birth weight, intrauterine fetal death

Left-to-right cardiac shunts:atrial septal defect, ventricular septal defect,

patent ductus arteriosus The incidence of congenital heart disease in pregnancy is

increasing - beter corresctive surgery in children Higher cardiac output does not increase shunting becouse

of attenuating effect of the decrease in peripheral vascular resistance

Pregnancy, labour and delivery – well tolerated unless pulmonary hypertension exists

Risk of paradoxical embolism! with atrial shunts (patent foramen ovale)

Aortic stenosisLeft ventricular outflow tract

obstruction

Heart failure / ischemia developement in severe stenosis (aortic valve area <1 cm² or transvalvular pressure gradient > 64mmHg)

Hypertrophic and noncompliant left ventricle

Complications with severe stenosis because of restricted ability to increase cardiac output

Management:

Symptomatic aortic stenosis: surgical correction first! then pregnancy

Absence of symptoms does not guarantee good tolerance of pregnancy!

If necessary: baloon valvuloplasty during labor and delivery

Coarctation of the aorta

Associated with: bicuspid aortic valve, aneurysms of the circle of Willis, ventricular septal defects, Turner syndrome

Risk of aortic rupture in the III trimester and during labor if CoA not corrected

If CoA corrected before pregnancy – risk of PIH developement due to residual abnormalities in aortic complience

Pulmonary valve stenosis Classification - according to the peak pressure

gradient across the valve:

mild <50mmHg; moderate 50-70mmHg; severe >80mmHg

Pregnancy well tolerated if stenosis mild or treated by valvuloplasty or surgery

Right-sided heart failure or atrial arrhythmias in severe stenosis (including asymptomatic!)

Management:

Severe pulmonary valve stenosis requires correction before pregnancy

If symptoms progress during pregnancy – baloon valvuloplasty

Tetralogy of Fallot If not corrected/palliated:- fall in systemic vascular resistance and

rise in cardiac outputexacerbate right-to-left shunting

- results: increased maternal hypoxemia and cyanosis

- poor fetal outcomes (loss rate ~30%)- maternal mortality risk 4 – 15%

If succesfully corrected: low risk; pregnancy well tolerated

Marfan syndrome

Connective tissue disorder

Autosomal-dominant

Complications due to medial aortopathy: dilation, dissection, valvular regurgitation

Aortic root replacement before pregnancy does not eliminate the risk of dissection of the residual native aorta!

Management

Recent data: maternal mortality rate: 1%; fetal mortality rate ~ 22%

Aortic root involvement: preconception counseling – risk in pregnancy

Little cardiovascular involvement; aortic root diameter < 40mm – good tolerance of pregnancy

Serial echocardiography to monitor for progressive aortic root dilation

Beta-blockers prophylactically – reduce aortic dilatation

Eisenmenger syndrome & pulmonary vascular obstructive

disease ES: pre-existing left-to-right shunt; pulmonary

pressure rise to systemic level; shunt flow right-to-left

Pregnancy complications: at term and during 1st postpartum week

High frequency of: spontaneous abortion, IUGR, preterm labor

Maternal mortality rate: primary pulmonary hypertention ~ 30%; Eisenmenger syndrome ~36%; secondary vascular pulmonary hypertention ~56%

Perinatal mortality due mainly to prematurity

Neonatal mortality rate: 12%

Preconception counseling: extreme risk from pregnancy; pregnancy is contraindicated!

Acquired heart disease - Mitral stenosis

The most common valvular lesion in pregnancy Hypervolemia and tachycardia exacerbate

transmitral gradient Symptoms: asymtomatic, dyspnoea, cough

Even asymptomatic patients (mild to moderate stenosis) can develope atrial fibrillation and heart failure in antepartum/peripartum period! Pulmonary oedema.

Outcomes

No maternal mortality

Morbidity (heart failure and arrhytmias)

Risk of complications higher in patients with a history of cardiac events: arrhytmias, stroke, pulmonary oedema

Fetal/neonatal outcomes: risk increases with severity of mitral stenosis

Management

In patients in NYHA class III or IV (despite optimal medical therapy), percutaneous mitral valvuloplasty during pregnancy should be considered

Other rheumatic lesions

Rheumatic aortic stenosis: risk similar to congenital aortic stenosis

Aortic or mitral regurgitation – well tolerated during pregnancy

Function may deteriorate (NYHA classification)

Peripartum cardiomyopathy

Idiopathic dilated cardiomyopathy, involves ventricular systolic dysfunction that developes during the last month of pregnancy or in the first 5 months after delivery in patients with no known underlying disease

Heart failure – the most common manifestation; others: arrhytmias, embolic events

Outcomes: improvement in NYHA functional status postpartum or persisting/worsening heart lesion

Relapse rate in subsequent pregnancy:- Substantial in women with persisting cardiac

enlargement / left ventricular dysfunction- Possibility of persistent subclinical

dysfunction (despite of recovered systolic function)

Atheromatous coronary artery disease

If possible – assessment (exercise testing) and treatment (coronary bypass surgery) before pregnancy

Risk in pregnancy: angina developement, myocardial infarction, especially in the peripartum period

Coronary angiography: recognition of mechanism of the infarct

Management

Thrombolytics shoul be avoided if coronary artery dissection occured

Percutaneous intervention (PCI) with stenting is optimal

Differentiate with: congenital coronary anomalies, disease with aneurysm formation, coronary arteriitis, autoimmune vascular diseases

Clinical approach - general recommendations:

1. Risk stratification

2. Antepartum management

3. Peripartum management

4. Recurrence of congenital lesion in the

neonate

5. Site of antepartum and peripartum care

Risk assessment

Cardiovascular history and examination 12-lead electrocardiogram Transthoracic electrocardiogram Arterial oxygen saturation measurement by

percutaneous oximetry in cyanotic patients Define underlying cardiac lesion Assess: ventricular function, pulmonary pressure,

severity of obstructive lesions, persistence of shunts, hypoxemia

Low risk

Small left-to-right shunt Repaired lesions without residual cardiac

dysfunction Isolated mitral valve prolapse without significant

regurgitation Bicuspid aortic valve without stenosis Mild/moderate pulmonic stenosis Valvular regurgitation with normal ventricular

systolic function Patient can be managed in a community hospital

High risk

Significant pulmonary hypertention Marfan syndrome with aortic root or major

valvular involvement Peripartum cardiomyopathy with residual left

ventricular systolic dysfunction

Patient should be managed in a high-risk pregnancy unit by a multidisciplinary team staffed by obstetricians, cardiologists, anesthesiologists and pediatricians

Antepartum management

Limiting activity in severely affected patients; hospital admission by mid-second trimester

Pregnancy complications: early identification, aggresive treatment (ie. PIH, hyperthyroidism, infections, anemia)

Mitral stenosis: rather beta-blockers than digoxin Coarctation, Marfan syndrome, ascending

aortopathy: empiric therapy with beta-blockers

Arrhytmias: if possible, avoid drugs in the 1st trimester, but:

Drugs administration for patients with severe symptoms or poor tolerance of sustained arrhytmias

Antiarrhytmic drugs:

preferred: digoxin, cardio-selective beta-blockers, adenosine;

limited use: quinidine, sotalol, lidocaine, flecainide, propafenone;

contraindicated: amiodarone Electrical cardioversion is save Implantable cardioverter-defibrillator

Anticoagulation therapy

Oral warfarin: non teratogenic in dose <5mg per day; risk of fetal intracranial bleeding throughout pregnancy, especially during vaginal delivery unless warfarin stopped before labor

Heparin: less effective in patients with prosthetic valves, safe for the fetus 6-12 Hbd

Low-molecular-weight heparin: more stable anticoagulation level

Low-dose aspirin in women with prosthetic valves as a part of antithrobotic regimen

Peripartum management

Elective cesarean section - indicated for: aortic dissection, Marfan syndrome with dilated aortic root, taking warfarin within 2 weeks of labour

Preterm planned induction: in high-risk patients to ensure that appropriate staff and equipment are avaliable; uncommon

Hemodynamic monitoring: no consensus on using invasive procedures during labor and delivery

Replace anticoagulants by heparine at 36 Hbd Give up heparin at least 12 hours before induction Routine antibiotic prophylaxis for endocarditis:

controversial in cesarean section or uncomplicated vaginal delivery; indicated in patients with prosthetic valves or previous endocarditis

Pain control: epidural anaesthesia and adequate volume preloading is recommended

Positioning the patient on her left side lessens hemodynamic fluctuations associated with contractions

Forceps or vacuum extractor at the end of second stage to shorten delivery

Postpartum monitoring of patients at intermediate or high risk: for at least 72 hours

Risk of congenital heart disease in offspring

0.4 - 1% in general population

10 - fold increase if a first-degree relative is affected

Patients of reproductive age with congenital heart disease should be offered genetic assessment and counseling: estimation of transmission risk and information of the options for prenatal diagnosis