Book of Medical Disorders in Pregnancy - Tintash

Chapter No: 5
HEART DISEASE IN PREGNANCY
Heart disease is one of the major causes
of maternal mortality. Its incidence
varies between 1 to 3.7 per cent of all
pregnancies. The complication is more
frequent in areas where predisposing
factors such as rheumatic fever syphilis
and other diseases which can affect the
cardiovascular system are more prevalent.
The lost common variety of heart
disease encountered during pregnancy is
the rheumatic heart disease; this is responsible
for about 85 per cent of all
cases, 75 per cent of which include
involvement of the mitral valve alone
while 10 to 15 per cent involve both the
mitral and the aortic valves. A small
number of cases are due to lesions of the
aortic and the tricuspid valves.
Congenital heart disease is responsible
in about 1 to 3 per cent cases. These
lesions include septal defects, tetralogy
of F allot and heart block. Hypertensive
heart disease accounts for 1 to 2 per cent
of total cases. Coronary heart disease,
coarctation of the aorta, bacterial
endocarditis and arteriosclerotic heart
disease are rarely encountered in
pregnant patients.
Normal heart
Enlarged heart
due to
cardiomyopathy
Fig5.1: Shows Human heart both
normal and enlarged in size
Physical adjustments in the
cardiovascular system:
67
The heart is pushed upward and to the
left by elevation of the diaphragm,
making the heart appears larger than
normal.
Its volume is increased by nearly 10 per
cent of the normal base value. The
increase in volume is due to hypertrophy
of the cardiac muscle and increase in
volume of blood available for filling the
heart. There is a slight increase in heart
rate during pregnancy.
Blood Pressure - Both the systolic and
diastolic blood pressure decrease around
mid term. These decreases in pressure
never exceed more than 10 mm of Hg in
normotensive patients. Patients who
have essential hypertension can show a
significant: decrease in pressure earlier
in pregnancy but a considerable increase
later in pregnancy.
Age of Woman Blood Pressure
15-19 117/77mmHg
20-24 120/79mmHg
25-29 121/80mmHg
30-34 122/81mmHg
35-39 123/82mmHg
40-44 125/83mmHg
45-49 127/84mmHg
50-54 129/85mmHg
55-59 131/86mmHg
60-64 134/87mmHg
Fig5.2: Shows women average of
blood pressure