What is Cardiac Disease in Pregnancy?
Heart problems during pregnancy cover a wide range of issues. There are many heart conditions in pregnancy that we’re still studying and trying to understand. Some of these problems might worsen conditions that the pregnant woman already has, while others might be new conditions that start because of the many changes happening in the body during pregnancy. Conditions that the woman might already have, and that can increase the risk of heart problems, include high blood pressure, diabetes, and congenital heart disease (a heart problem that someone is born with).
Despite this, heart disease during pregnancy is an important cause of illness and death, and is found in about 1 to 4% of all pregnancies. However, the majority of these cases can be successfully managed through early detection and careful monitoring during routine prenatal care.
What Causes Cardiac Disease in Pregnancy?
When it comes to heart diseases during pregnancy, the causes can be numerous and depend on the specific condition. Here’s a brief rundown of a few common heart problems during pregnancy and what experts believe might cause them:
* Heart muscle disease, or cardiomyopathy: There are several theories about what causes this. Possible causes include viral infections of the heart, autoimmune conditions, problems with the body’s fluid regulation, and a unique phenomenon known as microchimerism. It’s important to remember that the same factors that cause heart muscle diseases in people who aren’t pregnant can still play a role during and after pregnancy. Because of pregnancy, the heart might be more vulnerable these risks. These factors include drinking alcohol excessively, using certain chemotherapy drugs like doxorubicin, and abusing drugs like cocaine and methamphetamines.
* Coronary artery disease: This refers to diseases that involve blocked blood flow to the heart. The causes of this for pregnant women are similar to those for women who aren’t pregnant. Risks include high blood pressure, high cholesterol and triglyceride levels, diabetes, obesity, smoking, and lack of movement.
* Heart attacks during pregnancy: Just like coronary artery diseases, the same risk factors apply. Some complications of pregnancy, like preeclampsia and eclampsia, which are characterized by high blood pressure, can potentially increase the risk of heart attacks.
* Valve disease: This has to do with problems in the structure of the heart’s valves. While pregnancy might make these problems worse, it’s unclear if pregnancy plays a specific role in new valve disorders that emerge during pregnancy.
Risk Factors and Frequency for Cardiac Disease in Pregnancy
The exact rate of heart disease in women, especially during pregnancy, is not fully known. We also don’t know if there are more cases in developed countries as compared to less developed ones. But, based on the available data, we know that heart disease complications occur in at least 0.2% of pregnancies but could be up to 4%. If we include problems due to high blood pressure, the numbers could be even higher, potentially affecting up to 8% of pregnancies.
- The exact rate of heart disease in women and during pregnancies is not fully known.
- It’s unclear if heart disease occurs more frequently in developed vs. less developed countries.
- Available data suggests that at least 0.2% – 4% of pregnancies experience complications due to heart disease.
- When considering high blood pressure complications, up to 8% of pregnancies could be affected.
Signs and Symptoms of Cardiac Disease in Pregnancy
It’s important to accurately figure out if a pregnant woman has heart problems. They could be a possibility if the woman is experiencing certain symptoms such as:
- Fatigue
- Shortness of breath
- Trouble breathing when active
- Waking up at night with trouble breathing
- Trouble breathing when lying flat
- Increasing swelling
- Chest pain or heartburn-like discomfort
- Fainting or feeling lightheaded
- Herself or family members having had heart disease while pregnant
On a physical exam, the following signs might be seen:
- Fast breathing
- Rapid heart rate
- Low blood pressure
- Bluish skin, lips, or nails
- Clubbed fingers and toes (usually a longer-term symptom)
- Bulging neck veins
- Crackling sounds when you listen to the lungs
- Fluid in the abdomen
- Enlarged liver
- Swelling of the legs, ankles or feet
- Third and fourth heart sounds (S3, S4)
- Vein in neck showing changing pressure when you press on the liver
- Unusual pattern of neck veins
- Apical pulse (the pulse at the apex of the heart) is moved to the side
- Extra heart sounds
Many of these signs can also be seen in healthy pregnant women. That’s why it’s a challenge for doctors to figure out which of these signs are normal bodily changes and which are signs of heart disease. It’s critical to combine the woman’s medical history with physical exam findings to make the distinction clearer.
Testing for Cardiac Disease in Pregnancy
Testing for heart disease during pregnancy can sometimes require a more detailed approach. Your doctor might start by running basic tests such as blood tests and urine tests. These tests can hint at what might be going wrong in your body.
For example, a high count of white blood cells in your blood can signal heart inflammation or a heart attack. Regular monitoring of creatinine, a waste product that your kidneys filter out of your blood, can give your doctor an idea about whether your body has been receiving less blood than it needs. High levels of certain liver enzymes could mean you have congestive hepatopathy, a condition where a damaged liver swells due to blood flow issues. A urine test showing too much protein could suggest that you’re in a state known as pre-eclampsia, a pregnancy complication characterized by high blood pressure. The hormone brain natriuretic peptide (BNP) may also be checked as its levels tend to increase during pregnancy and can be found at higher levels in women with heart muscle disorders during pregnancy.
An electrocardiogram, a test that measures the electrical activity of the heart, can also be useful in diagnosing heart disease. Pregnancy can cause the heart to shift slightly and enlarge, causing changes in the heart’s electrical activity and sometimes leading to abnormal heart rhythms. These can include irregular rhythms originating from the upper or lower chambers of the heart.
Current or past damage to the heart muscle due to improper blood supply could cause changes in the electrocardiogram such as ST-elevations or depressions, T-wave inversion, or formation of Q-waves. Non-specific changes to ST-segment or T-waves are not uncommon in pregnancy, occurring in up to 14% of pregnancies.
A test called an echocardiogram, which uses sound waves to create pictures of the heart, is an important tool for evaluating heart problems in pregnancy. The test may reveal an enlargement of the chambers of the heart, a leaky heart valve, dilatation of the valves, and thickening of the heart walls.
These findings may or may not be significant, depending on your symptoms and how severe the echocardiographic findings are. There’s no clear line that defines what’s “normal” or “abnormal” in pregnancy. If your doctor suspects you have a heart muscle disorder, the echocardiogram can confirm the diagnosis if it shows that your heart’s ejection fraction, a measure of how well your heart is pumping, is less than 45% and/or M-mode shortening below 30%, and end-diastolic dimension is greater than 2.7cm/m2.
Localized movement abnormalities in the heart wall can suggest damage due to insufficient blood supply to the heart muscle. The echocardiogram can also show if there’s fluid around the heart. This is often harmless, but if you’re showing signs suggestive of a condition called cardiac tamponade, such as low blood pressure or neck vein distention, your doctor can assess you further using the echocardiogram.
Treatment Options for Cardiac Disease in Pregnancy
There are no universal preventive measures for heart disease during pregnancy. If you’ve had heart issues in the past, it’s necessary to be extra careful during your pregnancy. You should continue with your usual treatment routine unless it involves drugs that may harm your unborn child. In this case, a healthcare professional will give you alternatives. Different heart conditions require different treatment plans. Here are some common heart conditions and recommended treatments during pregnancy:
Ventricular dysfunction refers to a condition where your heart isn’t pumping blood efficiently. Some women may enter pregnancy with this condition, which could become worse due to the changes brought about by pregnancy like increased heart rate and volume of blood circulating in the body. By the second trimester, these individuals might experience severe worsening of their underlying disease. Some of the medications used to treat heart failure can continue to be used during pregnancy, except for some types of drugs known as ACE inhibitors and ARBs, which are known to potentially harm the baby. Hydralazine, a drug that relaxes blood vessels and increases heart output, coupled with nitrates, is a recommended alternative. Also, specific heart-rate controlling drugs, called beta-blockers, can be continued.
Peripartum cardiomyopathy is a heart muscle disorder that affects women in the last month of pregnancy or within five months after childbirth. This condition is treated similarly to ventricular dysfunction. However, ACE inhibitors or ARB therapy can resume post-delivery, once there’s no risk to the baby.
Mitral stenosis has to do with the narrowness of the mitral valve in your heart, with the potential to lead to serious health conditions among pregnant women. No known medications can reverse this disease. However, beta-blockers are often administered, which aid in reducing the amount of blood that goes back into your lungs instead of to the rest of your body.
Aortic stenosis obstructs the flow of blood from your heart to the rest of your body. This condition is less common in pregnant women but can be more challenging to manage. Heart medications don’t usually have a significant effect on this disease, and diuretic therapy, drugs that help expel salt and water from the body, should be used with caution.
Fast heart rhythms, or tachyarrhythmias, require individualized treatment. However, certain medications are considered safe to use during pregnancy to manage this condition.
Spontaneous Coronary Artery Dissection (SCAD) affects the blood vessels of the heart. SCAD could lead to a heart attack and is seen relatively more in pregnant women. The treatment approach for SCAD in pregnancy isn’t standardized due to its rarity but can involve multiple strategies including heart transplantation, open heart surgery or medication.
Acute coronary syndrome and heart attack are rare in pregnant women, but the risk increases with age as it allows for factors like diabetes, high cholesterol, and high blood pressure to come into play. Although exposing a pregnant woman to radiation isn’t ideal, in such cases, an angioplasty should be attempted with protection for the mother. Also, drug-eluting stents, which are tubes inserted into an artery to keep it open, should be avoided if possible because of a prolonged need for specific therapy that prevents blood clotting. A list of commonly used heart medications and their safety during pregnancy are as follows:
Morphine, metoprolol (a type of beta-blocker), calcium channel blockers, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers (in the first trimester), statins, different forms of heparin (a type of anticoagulant), aspirin, and glycoprotein inhibitors. Blood pressure over 160/100 should be brought under control with close monitoring. Antihypertensive agents that are considered safe for use during pregnancy include methyldopa, labetalol, nifedipine, hydralazine, and nicardipine.
What else can Cardiac Disease in Pregnancy be?
Heart conditions that occur during pregnancy need to be examined because they might be brand new or may be making preexisting conditions worse. When heart disease is found during pregnancy, it’s crucial to check for already existing conditions. These existing conditions could include:
- Dilated cardiomyopathy – a condition where the heart can’t pump blood effectively because it’s too weak or stiff
- Restrictive cardiomyopathy – the heart is rigid and cannot fill with blood properly
- Hypertensive obstructive cardiomyopathy – a heart condition caused by high blood pressure
- Ischemic heart disease – a condition where the heart muscle doesn’t get enough blood
- Previous valvular disorders – problems with the heart’s valves
What to expect with Cardiac Disease in Pregnancy
The World Health Organization (WHO) has developed guidelines to assess the risks pregnant women with heart conditions may face. These guidelines are broken down into four categories, ranging from no identifiable risk to extreme risk.
* Category I: No elevated risk of health problems or death.
* Category II: Mildly increased risk of death; moderate risk of health problems.
* Category III: Considerably high risk of death; severe health complications. Women in this category should receive regular check-ups and cardiac monitoring throughout and after pregnancy with heart specialists.
* Category IV: Extremely high risk of death; severe health complications. Pregnancy is highly discouraged for women in this group. If they choose to become pregnant, monitoring equivalent to category III should take place.
The specific conditions that fall into each category are:
* Category I: simple or repaired conditions such as pulmonic stenosis, mitral valve prolapse, and certain types of heartbeats.
* Category II: conditions like unrepaired atrial defects and ventricular defects.
* Category III: Serious conditions like mechanical heart valves and unrepaired heart defects.
* Category IV: conditions such as pulmonary arterial hypertension and severe aortic stenosis.
Though pregnancy is riskier for women with heart conditions, successful outcomes are common with regular follow-up care. However, some heart conditions during pregnancy carry greater risks than others.
For instance, peripartum cardiomyopathy, a type of heart failure that can occur during pregnancy, affects about 1 in 2289 live births. Thankfully, in about 75% of these cases, women regain their normal heart function.
Congenital heart defects, which are abnormalities present at birth, generally have a positive outlook. One study found no deaths among 90 pregnant women with these defects. Yet, some may develop lung-related complications or heart rhythm disturbances.
Acute coronary syndrome, a sudden decrease in blood flow to the heart, is rare during pregnancy. Risk of death in these cases is 7.3%, with risks being highest when this condition appears in the final trimester of pregnancy.
In summary, while the presence of heart disease can complicate pregnancy, with careful monitoring and medical supervision, many women can have successful outcomes.
Possible Complications When Diagnosed with Cardiac Disease in Pregnancy
Pregnancy can come with additional risks for women with heart disease. These can include:
- Gaining too much weight
- Preeclampsia, which is a condition causing high blood pressure
- Having the baby prematurely
- The baby not growing properly inside the womb
- Heavy bleeding or hemorrhage
- The placenta detaching from the womb prematurely, known as placental abruption
- Developing high blood sugar levels during pregnancy, known as gestational diabetes
- Worsening heart failure
- Potential death of the mother or baby
Preventing Cardiac Disease in Pregnancy
From the start, it’s crucial for patients to understand their heart conditions and to actively participate in making decisions about their treatment. It’s very important to thoroughly explain the potential risks to both the patient and their unborn child. As soon as a woman becomes pregnant, she should be given advice about risks related to heart disease during pregnancy. These risks can include using drugs, drinking alcohol, high blood pressure, diabetes, already having a heart disease, inflammation of the heart, and having a family history of heart disease during pregnancy.
