Approach to cardiac diseases in pregnancy

Approach to Cardiac Disease in Pregnancy

Mehul Bhatt, MD

Athens Heart Center

March 13, 2009

Approach to Cardiac Disease in Pregnancy

Physiological changes in pregnancy

Systematic approach to cardiac lesions

Principal of monitoring and treatment

Individualizing treatment to each patient

Normal Physiological Changes in Pregnancy

Framework to understand effects of cardiac pathology

Tremendous cardiocirculatory changes in normal pregnancy:

• SV (increase 40-50%) • CO (increase 30-50%)

Examine changes at various points of pregnancy

Normal changes in physical exam, EKG, CXR, Echo, PA catheter


Braunwald E et al. Heart Disease. 2001. pg. 2173.


Changes in blood volume start by 6 weeks Most hemodynamic changes completed by 22-25

weeks(major underlying cardiac disease should present by this point)

Mechanisms of cardiovascular hyperactivity:• Estrogen levels

• Elevated renin-aldosterone levels

• Elevated chorionic somatomammotropin

• Elevated prolactin

• Fetus not necessary for changes to occur(as evidenced from hydatidiform moles)


Symptoms: • Decreased exercise tolerance / Tiredness – increased body

weight and physiological anemia• Orthopnea – pressure of uterus on diaphragm• Palpitations – usually sinus tachycardia• Lightheadness / Syncope – compression IVC, decrease CO • Dyspnea – 76% of women at 34th week

Physical Exam: Hyperventilation, peripheral edema, capillary pulsations, brisk PMI, palpable RV + PA impulse, bibasilar rales (from atelectasis), distended neck veins (promient a,v waves, brisk x,y descents)

May be similar changes from cardiac pathology in pregnancy


3rd heart sound in upto 90% Systolic ejection murmur – from hyperkinetic flow Most auscultatory changes resolved 1-2 weeks postpartum

Cutforth R et al. Heart sounds and mumurs in pregnancy. Am Heart J. 1966;71:741-747.


EKG changes• QRS axis deviation

• Small Q wave and inverted P wave in lead III

• Sinus tachycardia

• Increase R/S ratio in V1 and V2

CXR changes• Straightening of left upper cardiac border

• Horizontal positioning of heart

• Increased lung marking

• Small pleural effusion at early postpartum Echocardiogram

• Slightly increased EDdV and ESdV

• Slightly improved LV function

• Enlargment of ventricular dimensions

• Slight enlargement of left atrial size

• Small pericardial effusion

• Increased tricuspid annulus diameter

• Functional tricuspid regurgiation

Elkayam U et al. Cardiac Problems in Pregnancy. 1990.34-7.


Effect of position on IVC return Positioning in cardiac pathology

may be beneficial or detrimental



Labor and Delivery:• Pain / Anxiety – can increase CO by 50-61%

• Uterine contraction – 300-500 mL infusion into central venous system

• Cardiocirculatory effects of uterine contraction:

Parameter Change Comments

Blood Volume Increase 300-500 mL

Cardiac Output Increase 30-60% increase

Heart Rate Increase or Decrease

Blood Pressure Increase SBP and DBP

Peripheral Resistance Unchanged

O2 Consumption Increase 100% increase

Elkayam U et al. Cardiac Problems in Pregnancy. 1990. 16.


Labor and Delivery:

• Hemodynamic changes of pregnancy less dramatic in lateral position

• Maneuvers in delivery position depending on cardiac pathology


Labor and Delivery

• Epidural anesthesia – systemic vasodilation that can reduce SV• Poorly tolerated in patient who cannot increase SV,

fixed CO

• Cesarean section – with GETA• Reduced maternal metabolic needs and

stabilization of blood volumes


Parameter Change Comment

Blood Volume Decrease Blood loss

CO Increase 60-80% immediate increase followed by rapid decrease, returns to normal levels in few weeks

SV Increase

HR Decrease

BP Unchanged

SVR Increase Loss of low resistance placenta

Hemodynamic Changes Postpartum

Cardiac Diseases in Pregnancy:Basics

Cardiac disease hinders physiological reserves

Increasing incidence congenital heart disease

Decreasing incidence of rheumatic heart disease

Cardiac Disease in Pregnancy:Basics

Non-cyanotic cardiac disease• NYHA Functional Class

• Maternal mortality

• Class I and II: 0.4%

• Class III and IV: 6.8%

• Fetal mortality

• Class I: negligible

• Class IV: 30%

Cyanotic cardiac disease• 45% rate of fetal death

• Low birth weight and immaturity

Cardiac Disease in Pregnancy:Congenital Heart Disease

Increased CO and blood volume on already stressed hemodynamic system

Lesions with volume overload

Lesions with obstruction

Atrial septal defectVentricular septal defectPatent ductus arteriosus

Aortic stenosisCoarctation of the aortaPulmonary stenosisTetrology of Fallot

Cardiac Disease in Pregnancy:Cardiac Lesions

Pregnancy well tolerated

(except if progress to Eisenmenger’s syndrome)

(able to tolerate increased volume)

Pregnancy poorly tolerated

Mitral regurgitationAortic regurgitationAtrial septal defectPatent ductus arteriosisPulmonary stenosisHypertrophic obstructive cardiomyopathy (may even benefit from increased preload)

Obstructive (Fixed CO)•Mitral stenosis

•Aortic stenosis

•Coarctation of aortaCyanotic

•Any lesion with Eisenmenger’s syndrome

•Primary pulmonary hypertension

•Tetralogy of FallotVolume limited

•Marfan’s with aortic root involvement

•Aortic dissectionActive rheumatic carditisAny lesion with Class III or IV symptoms

Cardiac Disease in Pregnancy:Cardiac Lesions

Factors that increase risk of CHF with pregnancy:• Age > 30 YO

• Gestational age > 20 weeks

• Cardiac enlargement > 55% lung space on CXR

• Atrial tachycardia

• Physical effort

• Toxemia

• Infection

• Emboli

Cardiac Disease in Pregnancy:Monitoring and Treatment

In perfect world: • Diagnosis of cardiac disease prior to pregnancy

• Pre-pregnancy counseling of patient and partner with obstetrics, cardiology, and anesthesia involved

• Pre-pregnancy treatment• Medical therapy

• CHF treatment

• Arrhythmia management

• Surgical therapy• Valve replacement

• Congenital heart disease repair


General objectives of treatment• Shunts: avoid favoring R to L shunting, lower PA

pressures, avoid hypoxemia, avoid prolonged Valsalva

• Obstructive Lesions: β-blockers, avoid volume depletion, maintain preload

• CHF: diuretics (only with pulmonary edema), reduce afterload

• Arrhythmias: rate and rhythm control, anticoagulation as necessary, higher dose digoxin

• Tenuous aorta (Marfan’s, aortic dissection): β-blockers (reduce dp/dt)


Indications for considering PA catheter:• NYHA Functional Class II, III, IV• Mitral stenosis• Aortic stenosis• Pulmonary hypertension• Pulmonary edema• Hypoxemia• Ischemic heart disease• Intractable hypertension• Oliguria unresponsive to fluids

Risk of PA catheter:• Increased procedural fear and pain leading to increased CO


Labor and Delivery:

• Epidural anesthesia:

• Systemic vasodilation

• Decrease CO 25-45% even in normal patients

• Well tolerated (often beneficial):

• AR, MR, L to R shunts

• Poorly tolerated:

• Limited ability to increase SV

• R to L shunts

• AS, MS

• Hypertrophic CM

• Pulmonary hypertension without ASD


Labor and Delivery

• Caesarian section recommended:

• Obstetrical reasons

• Anticoagulation with coumadin• Avoid forceps, use vacuum/suction devices

• Severe fixed obstructive cardiac lesions• Avoid vasodilation (reduced preload) with epidural

anesthesia

• Severe pulmonary HTN

• Marfan’s with dilated aorta or aortic dissection• Avoid increased blood volume, aortic stress with

contractions


Labor and Delivery• Shorten stage II labor

• Prolonged valsalva• Increase PA pressures, Increases R to L shunting• Shunts: ASD, VSD, Tetralogy of Fallot, Eisenmenger’s

• Maternal Position:• Supine versus lateral decubitus

• Consider lateral decubitus with obstructive lesions• Consider supine with CHF

• Post-delivery:• Continue monitoring

• Increased CO (returns to normal after several weeks)• Increased SVR (with loss of placenta)• Hemorrhage risk

Cardiac Disease in Pregnancy:Highest-Risk Cardiac Lesions

Suprasystemic pulmonary vascular resistance (Eisenmenger’s syndrome)

Marfan’s syndrome with dilation of the aortic root

Peripartum cardiomyopathy with persistent cardiac enlargement

Cardiac Disease in Pregnancy:Peripartum Cardiomyopathy

Incidence: 1 in 4000 pregnancies More common after age 30 Can result in severe CHF Clinically present by 3rd trimester Close hemodynamic monitoring and early delivery

maybe necessary Cardiomyopathy may persist even after delivery High rate of recurrence so birth control

recommended

Cardiac Disease in Pregnancy:Acute Myocardial Infarction

Rare in pregnancy• 1 in 10,000 to 30,000 pregnancies

Coronary dissections Thrombolytic therapy relatively contraindicated Primary angioplasty safe after 1st trimester

with lead shielding over fetus

Cardiac Disease in Pregnancy:Anticoagulation

Increased thrombogenicity in pregnancy• Increased fibrinogen

• Increased factors II, VII-X

• Increased von Willebrand factor

• Increased endothelial cell inhibitor of tPA

• Increased placental inhibitor of tPA

• Decreased protein S

Same indication as in non-pregnant Mechanical valves still particularly challenging


Anticoagulants:• Warfarin

• 1st trimester teratogenicity – due to low levels of Vit. K clotting factors in early fetus

• “Coumadin embryopathy”: Facial abnormalities, optic atrophy, mental impairment (5-25% risk)

• Possibly dose related effects (one study)

• Higher rates of spontaneous abortion

• Unfractionated Heparin

• Used during 1st trimester to avoid coumadin embryopathy

• Subcutaneous unfractionated heparin still see fatal valve thrombosis


Anticoagulants• Low molecular weight heparin (LMWH)

• Seemed easy, cost-effective, non-teratogenic

• Effective in DVT, antiphospholipid syndrome in pregnancy

• Safe in peri-procedural bridging in non-pregnant patient with mechanical valve replacements

• Randomized trial of LMWH in prosthetic heart valves terminated after 12 patients enrolled secondary due to 2 deaths from prosthetic valve thrombosis

Cardiac Disease in Pregnancy:Prosthetic Valves

Treatment dilemma:• Warfarin best for prevention of thromboembolic events, but fetal

safety issues

• Heparin reduces fetal complications, but dosing issues increase risk of thromboembolic events

Consider bioprosthetic valves in women of childbearing age or planning pregnancy

Anticoagulation with mechanical valves• Very high risk patients

• Limited data

• ACC / AHA Guidelines

Cardiac Disease in Pregnancy:Prosthetic Valves


Cardiac Disease in Pregnancy

Framework for evaluation and treatment

Individualized management

Anticoagulation with mechanical valves remains challenge

Approach to cardiac diseases in pregnancy

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