Pregnant women at risk of heart ailment
Updated 11:01 am, Wednesday, March 26, 2014
Women know the side effects of pregnancy only too well: fatigue, shortness of breath, discomfort while lying flat, swollen feet.
Sometimes those aren't mere annoyances. In extreme cases, they can be symptoms of a life-threatening heart ailment, peripartum cardiomyopathy.
The disease is centered in the heart's muscles, which can falter in their job of pumping blood through the body. Symptoms appear in the last month of pregnancy or the five months after childbirth. Most cases respond to treatment, but the disease is unpredictable and little understood, says Dr. Biswajit Kar, chief of the medical division of the Center for Advanced Heart Failure at Memorial Hermann Heart & Vascular Institute.
Peripartum cardiomyopathy occurs in about 1 in 3,000 pregnancies in the United States, Kar says. But the disease's causes are unclear, and the center recently received a $100,000 grant to track and study cases.
Women in the last trimester of pregnancy, Kar says, should be on alert.
Q: What are the symptoms of peripartum cardiomyopathy?
A: The symptoms are very nonspecific. That's where the problem lies. The patient starts getting tired and is short of breath, or is not able to lie down flat, or has very swollen feet. Those are things that can happen to any woman with advanced pregnancy. It's only when it gets very severe that they may seek medical attention.
Q: What is going wrong inside the heart?
A: The heart is a pump, basically. It's pumping and squeezing. The purpose is to pump blood so that it meets all the demands of the mother's body. The fetus also gets blood through the placenta.
Once the heart becomes ineffective as a pump because the muscle of the heart is weakened, the demands of the body are not being met. So you have fatigue and the other symptoms of low cardiac output.
Also, because the right side of the heart is pumping into the left side, and the left side is failing, the pressure in the right side starts going up. So fluid starts accumulating in the lungs, and you have shortness of breath.
Q: How does the disease progress?
A: Its course is very unpredictable. It can progress very rapidly to end-stage heart failure needing mechanical circulatory support or a heart transplant in a few days. Or it can go into a spontaneous resolution and complete recovery in a few weeks or a month. Mercifully, most completely recover, but about 10 percent or 15 percent die.
In extreme situations, where both ventricles are failing, you get into the low cardiac output stage. Your blood pressure drops and you go into a cardiogenic shock state, where the organs start to be affected. Your kidneys start failing; your liver starts getting congested and failing. That's what can spiral down to death.
Q: How will a pregnant woman know she should be checked?
A: In the last trimester of pregnancy, if she has unusual fatigue, shortness of breath or difficulty lying flat - if any of this is out of the ordinary compared to what she has been feeling - she needs to seek medical attention immediately.
Q: What will her physician do?
A: Someone can examine her and get a feeling for what the heart function is and get an echocardiogram done. That will show whether or not the heart is normal. It's a pretty easy test and noninvasive.
Q: What is the treatment?
A: You have to worry about the mother's health as well as the baby's health. If the (squeezing function of the heart) is down but the heart is not completely failing, we like to take the baby to term and deliver the baby as soon as possible, making sure the baby is viable and stable. The mother is usually treated with a mild diuretic to make sure the congestion in the lungs goes down. We also give some medicines that protect the heart - beta blockers and ACE inhibitors. These are used to unload the heart as much as possible and give it time to heal.
If the mother has a catastrophic collapse or advancing heart failure that jeopardizes her life, that also threatens the baby. If there is any evidence of fetal distress, we either induce delivery or do an emergency Caesarean section. The good new for the baby is that (peripartum cardiomyopathy) is usually diagnosed in the last four weeks of pregnancy, and the baby is usually viable by then.
Q: Can the mother have more children?
A: There is a significant chance of recurrence, so physicians universally discourage subsequent pregnancies. But the urge to motherhood is so strong that people who have recovered heart function would like to take a chance. In these cases, they would have the pregnancy under very close supervision.
Q: Are any groups of women particularly at risk of developing the disease?
A: African-American ethnicity is the strongest risk factor in the United States. Also, the more advanced the mother's age, the higher the risk.
Obesity and hypertension are risk factors. If you develop high blood pressure during pregnancy, that's another risk factor. If you've had multiple pregnancies or multiple gestations - twins or triplets - you have a higher chance of developing it. If you are using medicines that prevent going into premature labor, that predisposes you to (peripartum cardiomyopathy).