UNIQUE HIGH-RISK CONDITIONS
Eisenmenger syndrome is characterized by pulmonary hypertension and a
bidirectional intra-cardiac shunt. The normal decrease in systemic vascular
resistance (SVR) in pregnancy places the patient at risk for having the
pulmonary vascular resistance (PVR) exceed the SVR. When this develops,
the path of least resistance for blood from the right heart is to bypass the
pulmonary circulation across the shunt. This results in the left heart pumping
unoxygenated blood into the systemic circulation, resulting in a 50%
mortality risk. Management is by avoiding hypotension.
Marfan syndrome is an autosomal dominant connective tissue disorder. In
pregnancy, if the aortic root diameter is >40 mm, the risk of aortic dissection
is high, placing the patient at a 50% mortality risk.
In peripartum cardiomyopathy, the patient has no underlying heart disease
but develops idiopathic biventricular cardiac decompensation between the last
few weeks of pregnancy and the first few months postpartum. Risk factors
include advanced maternal age, multiparity, hypertension, and multiple
pregnancy. Mortality rate is 75% if reversal does not occur within six months.
Management is supportive, in intensive care.