What is Postpartum Cardiomyopathy?
Postpartum cardiomyopathy is a rare kind of heart failure that occurs after giving birth, where the heart becomes unable to pump blood effectively. We’re not sure what causes it and it was first identified in 1849. It’s diagnosed by the following criteria:
1. The woman, who was healthy before, begins to experience heart failure in the last month of pregnancy or within five months after giving birth.
2. There are no identifiable reasons for the heart failure.
3. The woman didn’t have any heart disease before the last month of pregnancy.
4. A heart scan (echocardiography) showed the left part of the heart isn’t pumping as well as it should.
The number of affected women can greatly vary based on their ethnic background and where they live. The outcomes can also range widely; some women might recover completely, while others might not survive.
It’s important to note that postpartum cardiomyopathy is diagnosed by ruling out other potential causes of heart failure. This means that only after all possibilities have been checked and excluded, it’s concluded that they have this condition.
What Causes Postpartum Cardiomyopathy?
We don’t fully understand how this disease works. Nonetheless, several ideas have been proposed to explain how it might occur. These include viral infections of the heart, lack of certain nutrients, the body’s immune system accidentally attacking its own tissues, the presence of cells from another individual in one’s body (microchimerism), strains on the heart due to blood flow issues, problems with blood vessels, hormonal disturbances, and genetic factors.
Risk Factors and Frequency for Postpartum Cardiomyopathy
A nationwide study found that the number of patients being diagnosed for a certain condition is about 10.3 for every 10,000 live births. This type of condition becomes more common as people get older, with the most cases occurring in people aged 40 to 54.
- African Americans and people living in the southern United States have the highest rates of this disease.
- Conversely, the occurrence of this disease is lowest amongst the Hispanic community.
- The disease is more frequently found in Asia and Africa.
- When it comes to heart failure due to pregnancy, Nigerian women have a high risk, with nearly 1 out of every 100 live births affected.
- Data revealed that in South Asia, between 1 in 837 and 1 in 1374 deliveries are affected by a condition called peripartum cardiomyopathy.
Thanks to new diagnostic techniques and increased awareness about postpartum cardiomyopathy, the number of cases identified has grown from 8.5 to 11.8 over recent years.
Signs and Symptoms of Postpartum Cardiomyopathy
Postpartum cardiomyopathy is a serious health condition that affects some women shortly after giving birth, often in the first week. Symptoms are similar to heart failure, including difficulty breathing while lying flat (orthopnea) and waking up from sleep with shortness of breath (paroxysmal nocturnal dyspnea). These situations can easily be mistaken for normal pregnancy side effects which can delay a correct diagnosis. When doctors examine a patient, they may find a faster heartbeat than normal (tachycardia), increased pressure in the neck veins (elevated jugular venous pressure), crackling sounds in the lungs due to fluid buildup (bilateral pulmonary crackles), an extra heart sound (S3), and a displaced heart beat. In extreme situations, a woman might struggle with acute respiratory failure or severe shock that decreases blood flow through the body which would require close monitoring in the intensive care unit.
There are several risk factors that increase the likelihood of developing postpartum cardiomyopathy. These include:
- Being older or younger than the average age for pregnancy
- Having been pregnant multiple times
- Carrying twins
- Long-term use of drugs to prevent early labor (tocolytic therapy)
- Being of African descent
- Living in poverty
- Having high blood pressure (hypertension)
- Abusing cocaine
Testing for Postpartum Cardiomyopathy
If you’re suspected of having a condition known as peripartum cardiomyopathy (PPCM), which is a form of heart failure that occurs during the end of pregnancy or the months following childbirth, your doctor might run some specific tests.
First, they may test your levels of B-type natriuretic peptide and N-terminal proBNP. These are substances that your heart makes more of when it has to work harder. In normal pregnancies, these levels tend to be lower, but in PPCM, they are typically elevated.
They might also suggest an ECG, or an electrocardiogram. This is a test that can show if your heart is beating too fast or if the electrical signals in your heart are delayed, which may show up as a specific pattern on the tracing, known as left bundle branch block (LBBB).
Your doctor may also suggest an X-ray of your chest. This can show if you have fluid in your lungs, called pulmonary edema, or if your heart is enlarged. You may also have extra fluid around your lungs, called pleural effusions.
One of the most useful tests in diagnosing PPCM is called an echocardiogram. This test uses sound waves to create a picture of your heart and can help differentiate this condition from other causes. It can show if the left side of your heart is bigger than it should be, if your heart isn’t squeezing as effectively as it should be, if your heart’s right side and the two top chambers or atria are enlarged, and if you have a condition known as pulmonary hypertension, which means high blood pressure in the arteries to your lungs.
Additionally, there are specific criteria on the echocardiogram that can help diagnose PPCM like an ejection fraction (the percentage of blood that leaves your heart each time it contracts) less than 45%, an end-diastolic diameter (a measure of your heart size) greater than 2.7 cm/m2 and/or M-mode fractional shortening (a measure of your heart’s contractions) less than 30%.
Another test is Cardiac MRI, which can give a very accurate measurement of your ejection fraction and help confirm the diagnosis.
Although a cardiac biopsy can be a useful test in diagnosing some heart diseases, it’s not usually needed for diagnosing PPCM. This would only be required if your doctor suspected a different cause for your heart failure, like cardiac sarcoidosis or giant cell myocarditis, which are other types of heart diseases.
Treatment Options for Postpartum Cardiomyopathy
Treatment for this condition usually involves relieving symptoms associated with heart failure. Standard therapy focuses on managing the patient’s fluid levels. The most commonly used medications include selective beta 1 blockers and ACE inhibitors, both of which have proven to lower the risk of death. However, it’s important to note that ACE inhibitors aren’t suitable for pregnant patients.
Diuretic drugs are often used to help manage symptoms related to heart failure. There are also newer medications for heart failure, such as sacubitril/valsartan, which have been found to potentially improve symptoms for heart conditions related to pregnancy.
Recent research shows that stress during the period following childbirth increases the production of abnormal 16-kDa prolactin. This substance can have harmful effects on the heart’s muscle cells. Bromocriptine, a medication that blocks prolactin and acts on dopamine receptors, can reduce the effects of 16-kDa prolactin on the heart’s muscle cells. In small studies, bromocriptine has been linked with improved patient outcomes.
Cardiac resynchronization therapy, a procedure that helps improve the heart’s rhythm, has also shown to improve the heart’s pumping effectiveness and patient outcomes when medication alone isn’t enough to manage the symptoms.
What else can Postpartum Cardiomyopathy be?
These are possible conditions or scenarios that could cause changes to a pregnant woman’s heart health:
- Normal changes that happen during pregnancy
- Takotsubo cardiomyopathy, a temporary heart condition
- Severe preeclampsia or eclampsia, which are pregnancy complications involving high blood pressure
- Pulmonary embolism – a blood clot in the lungs
- Previously unrecognised heart valve disease (for example, rheumatic valve disease)
- Acute pulmonary edema from prolonged tocolysis or preeclampsia, a condition causing fluid in the lungs
- Heart functioning issues due to ischemia or stress cardiomyopathy
- Heart functioning issues due to arrhythmia, or irregular heart rate
- Amniotic fluid embolism syndrome- a rare childbirth emergency
- Asthma
- Pneumonia
What to expect with Postpartum Cardiomyopathy
The long-term results of medical treatment can vary. About half of the patients see an improvement with standard medical treatment. But sadly, another 25% of them end up with chronic heart failure, a condition where the heart can’t pump enough blood to meet the body’s needs. The rest of the patients pass away during the course of the disease.
The size of the left ventricle (the main pumping chamber of the heart), if it’s more than 6cm, and the ejection fraction (the measure of how well your heart is pumping blood), if it’s lower than 30% at the time of diagnosis, are significant indicators of how likely it is for the left ventricle to recover.
Patients are generally advised against getting pregnant if the ejection fraction remains low, as this can lead to a high risk of death. However, if a patient wants to get pregnant, they typically should wait for at least 5 years after their ejection fraction has return to normal.
Possible Complications When Diagnosed with Postpartum Cardiomyopathy
Peripartum Cardiomyopathy (PPCM) can lead to some serious health issues, including:
- Worsening heart failure
- Cardiogenic shock, a severe condition where the heart can’t pump enough blood to meet the body’s needs
- Arrhythmias, or irregular heartbeats
- Thromboembolic events, which include stroke, TIA (a mini-stroke that lasts only a few minutes), and blood clots in the left chamber of the heart (LV apical clots)
- Death