HEART DISEASES IN PREGNANCY

Incidence and types of heart diseases in pregnancy

Incidence of heart disease in pregnancy is around 1%

These can be congenital and acquired of these, acquired heart diseases are most

common in developing countries. These include:

RHD, cardiomyopathies and ischemic heart disease

Congenital heart diseases can be:

left to right shunts, stenotic lesions, right to left shunts

Most common cardiac lesion in pregnancy is RVHD(MS)

Most common arrhythmia in pregnancy is SVT

Most common acyanotic heart disease in pregnancy is ASD(ostium secundum )

Most common cyanotic heart disease- TOF

HEMODYNAMIC CHANGES DURING PREGNANCY

Cardiac output:

increase in CO starts at ~5wk POG, reaches a maximum at 30-34 wk ( 40% increase over the prepregnant value) and remains elevated till term. During labour, it increases by ~20% with uterine contractions. Immediately following delivery CO increases further by~15-20%

return to pre labour value= 1 hr after delivery

return to pre pregnant value= 4 wk after delivery

Mechanism for increase CO increase Stroke volume = 27% increase heart rate = 17% increase in intravascular volume Intravascular volume (IVV) increase in blood volume starts around 6 wk

and gradually reaches a peak of ~30-40% by 32 wk

plasma volume~ 40-50% RBC volume~ 20-30% IVV expansion is marked by systolic ejection

murmur .

Systemic vascular resistance falls by 21% Pulmonary vascular resistance falls by 34% Colloid osmotic pressure falls by 14% Aortic root – increase in size and compliance Venous pressure-

femoral vein pressure:20cm of water (lying down) and 80 – 100 cm of water on standing.

BP: mid trimester fall in MAP of 10 -15 mm of Hg, reaching a nadir ~ 24-28 wk

No change in CVP

PCWP

NORMAL CARDIAC FINDINGS

Raised JVP with prominent pulsations Brisk and diffuse apex impulsation Loud s1 Loud s2 and widely split Occasional s3 Aortic or pulmonary flow murmurs Venous hum Mammary souffle

ABNORMAL CARDIAC FINDINGS

Progressive dyspnea or orthopnea Nocturnal cough Hemoptysis Syncope Chest pain Cyanosis Clubbing Persisstent neck vein distension Systolic murmur grade 3 or above

Diastolic murmur Cardiomegaly Persistent arrhythmia Persistent split s2

PERIODS DURING PREGNANCY WHEN DANGER OF CARDIAC DECOMPENSATION IS HIGH

12-16 WK- hemodynamic chngs of pregnancy begin

28-32 wk- hemodynamic chngs peak During labour and delivery Immediately following delivery of baby and

placental separation( max chances) 4-5 days following delivery

NYHA FUNCTIONAL CALSSIFICATION OF CARDIAC

DISEASE I No symptoms and no limitation in ordinary

physical activity, e.g. shortness of breath when walking, climbing stairs etc.

II Mild symptoms (mild shortness of breath and/or angina) and slight limitation during ordinary activity.

III Marked limitation in activity due to symptoms, even during less-than-ordinary activity, e.g. walking short distances (20-100 m).Comfortable only at rest.

IV Severe limitations. Experiences symptoms even while at rest. Mostly bedbound patients.

RISK OF MATERNAL MORTALITY AND MORBIDITY WITH HEART

DISEASE Group1( minimal risk) 0-1% ASD VSD PDA Corrected TOF Corrected congenital heart disease without

residual cardiac dysfunction MVP NYHA class 1,2

Group 2( moderate risk) 5-15% AS Marfan’s syndrome with normal aorta Uncorrected TOF Previous MI Artificial valve H/o peripartum cardiomyopathy with no

residual ventricular dysfunction NYHA class 3,4

Group3 (major) 25-50% Pulmonary hypertension Marfan’s syndrome with aortic valve

involvement Cardiomyopathy Complicated coarctation of aorta

PREDICTORS OF CARDIAC EVENTS DURING PREGNANCY(Sui and Coleman 2004)

N : NYHA grade 3,4 or cyanosis O : obstructive lesion of left heart MV area < 2 cm sq Aortic valve area< 1.5 cm sq pressure gradient > 30 mm of Hg P : prior cardiac event stroke/ arrythmia/TIA/stroke E : EF< 40%

Heart disease and none of above, risk of adverse cardiac event during pregnancy~ 5%

Heart disease with any one of above- 25% Heart disease with 2 or more of above- 75%

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