Cardiovascular Disease in Pregnancy

Songsak Kiatchoosakun M.D.Cardiology, MedicineKhon Kaen University

Introduction

Pregnancy, labor and delivery are associated with burdens on the cardiovascular system

The outcome of pregnancy is related to functional class and underlying heart disease

Hemodynamic Modifications during Pregnancy

Blood volume starts to rise at 5th week Systemic vascular resistance and blood

pressure are decreased Resting heart rate increases by 10-20

beats/min Cardiac output increases by 30-50%

High Risk Pregnancy Advise avoidance of pregnancy

– Mitral stenosis with functional class II-IV– Mitral and aortic regurgitation with functional class

III, IV– Severe pulmonary hypertension– Left ventricular dysfunction– Marfan’s syndrome with dilated aortic root

(> 40 mm)– Cyanotic heart disease– Severe obstructive lesion (aortic stenosis, pulmonary

stenosis)

High Risk Pregnancy

Close follow up required– Prosthetic valve– Mild to moderate valvular heart disease– Marfan’s syndrome without aortic root

dilatation

Signs and Symptoms in Normal Pregnancy

History– Dyspnea– Orthopnea– Palpitation

Physical examination– Edema– Systolic murmur < grade II/VI

– Increased of S1, P2

Suspicious Symptoms and Signs of Cardiac Disease in Pregnancy

Progressive dyspnea Syncope Chest pain Cyanosis Left parasternal heave A grade III/VI or greater systolic murmur Any diastolic murmurs S4 gallop Fixed split of S2

Opening snap

Cardiovascular Disease in Pregnancy

Valvular Heart disease– Rheumatic heart disease

Prosthetic heart valves Hypertension Congenital heart disease Peripartum cardiomyopathy Marfan syndrome and aortic regurgitation Arrhythmias

Valvular Heart Disease and Maternal Outcomes

0

10

20

30

40

CHF Arrhythmia Hospitalization

Control

VHD

%

Hameed A. J Am Coll Cardiol 2001;37:893

Valvular Heart Disease and Fetal Outcomes

0

5

10

15

20

25

Preterm labor IUGR

Control

VHD

%

Hameed A. J Am Coll Cardiol 2001;37:893

Mitral Stenosis Most common valve disease in pregnancy Valve area < 1.5 cm2 increases risk of

– Pulmonary edema– Heart failure– Arrhythmias– Intrauterine growth retardation

Closed follow up is necessary– Doppler echo at 3 and 5 month and

monthly thereafter

Diagnostic Assessment

Echocardiography– Confirm diagnosis– Determine the severity of stenosis– Pulmonary artery pressure and RV function– Mitral valve score to determine the success of

percutaneous mitral balloon valvuloplasty

Medical Management

Most pregnant woman with mitral stenosis can be managed medically

Limit activity Restrict salt and fluid Diuretic if needed

Medical Management

Digoxin is useful in atrial fibrillation Rheumatic prophylaxis

– Penicillin V 250 mg X 2

– Benzathine Penicillin IM q 3 weeks Betablocker

Beta-blocker in Pregnancy

Beta-1 selective agents ;metoprolol and atenolol limits the risk interaction with uterine contraction

Cross placenta and excrete in breast milk No serious adverse effects on neonates Fetal bradycardia and hypoglycemia

have been reported

Percutaneous Balloon Mitral Valvuloplasty (PBMV)

Should be considered after failure of aggressive medical treatment

Radiation exposure and technical difficulties are major limitations

Transesophageal echocardiography guidance may decrease the fluoroscopy time and maternal complications

Surgical Intervention

Indicated in patients who failed medical treatment

Should be performed between 24-28 weeks’ gestation

Maternal mortality rate 1.5-5% Fetal mortality rate 20-30 % in open heart

surgery Closed mitral valvotomy is preferable

– safe for mother– fetal mortality of 2-12%

Regurgitation Valve Disease

Pregnancy is generally well tolerated even in severe valve regurgitation

The decrease in vascular resistance and tachycardia during pregnancy reduces the regurgitation fraction

Medical therapy in patients with heart failure– Nitrate– Dihydropyridine calcium blockers– ACE inhibitors and ARB are contraindicated

Pregnancy with Heart Valve Prostheses

Problems

– Hypercoagulable state during pregnancy

– Use of oral warfarin is associated with fetal anomalies (nasal hypoplasia, epiphysis stippling, CNS anomalies) » Overall risk is 5%» Dose related; low risk if daily dose < 5 mg

Regimens of Anticoagulant

Regimen 1-Warfarin sodium through out pregnancy with unfractionated heparin sodium near term

Regimen 2-Substitution or warfarin with unfractionated heparin between 6-12 weeks and near term

Regimen 3-Unfractionated heparin through pregnancy

Fetal Complications

0

5

10

15

20

25

30

Abortion Anomalies

Regimen 1

Regimen 2

Regimen 3

%

Chan WS. Arch Intern Med 2000;160:191

Maternal Complications

0

5

10

15

20

25

30

35

Thrombus Death

Regimen 1Regimen 2Regimen 3

%

Chan WS. Arch Intern Med 2000;160:191

Conclusions

Risk of embryopathy (4-6%) when warfarin is used during 6-12 week of gestation

Subcutaneous heparin does not provide adequate anticoagulation

No advantage in the use of heparin during 6-12 week of gestation to prevent fetal wastage

Heparin in first trimester is associated with high incidence of thromboembolism

Recommendations Warfarin therapy throughout pregnancy

is the safest therapeutic option for the mother

Patients who choose not to take warfarin should receive unfractionated heparin or low molecular weight heparin (aPTT 2-3 time control, predose anti Xa ~ 0.7)

Warfarin should be replaced by heparin at the 36th week to avoid neonatal intracranial hemorrhage

Hypertension in Pregnancy

Complicates 6-8 % of all pregnancies Complications

– Cerebral hemorrhage– Hepatic failure– Acute renal failure– Abrutio placenta

Pregnancy outcomes relate with underlying causes of HT

Pharmacological Treatment Methydopa: first line agent; 750 mg-4 g Betablocker Calcium channel blocker Hydralazine Diuretics:

– Contraindicated in preeclampsia– May reduce uteroplacental flow

ACEI and ARB blocker: renal agenesis

Cardiovascular Drugs in Pregnancy

Drug Use in pregnancy SafetyDigoxin HF, arrhythmia Safe

Beta-blocker HT,MS, IHD Safe

Nifedipine HT Safe

Hydralazine HT, HF Safe

Nitrate IHD Limited data

Diuretics HF,HT +/-

ACEI HT, HF Unsafe

Amiodarone Arrhythmias Unsafe

Cardiovascular Evaluation in Pregnancy

History Physical examination Investigations

– ECG– Echocardiography

Management

Low risk patients– HT stage I without end organ damage– Control of HT before conception– Frequent supervision is essential

High risk patients– Severe HT with end organ damage and

co-morbidity condition– Need frequent assessment

Hypertensive Disorder

Classification and definition Chronic HT: HT prior or before 20 wks of gestation Preeclampsia-eclampsia: proteinuria with new

HTafter 20 wks of pregnancy Pre-eclampsia superimposed on chronic HT:

increased BP (30/15); change in proteinuria or target organ damage

Gestational HT: new HT after 20 wks of pregnancy without proteinuria

Transient HT: elevated HT during or after pregnancy without sings of preeclampsia