Peripartum Cardiomyopathy

pregnant woman in bed

What is peripartum cardiomyopathy?

Peripartum cardiomyopathy (PPCM), also known as postpartum cardiomyopathy, is an uncommon form of heart failure that happens towards the end of pregnancy or in the months following delivery, when no other cause of heart failure can be found. PPCM is most commonly diagnosed in the last month of pregnancy and the weeks following delivery but can occur up to five months into the postpartum period. PPCM is diagnosed in individuals without a prior diagnosis of heart disease. Cardiomyopathy means heart muscle disease but is often described as heart muscle weakness.

In PPCM the heart chambers enlarge and the heart muscle weakens. This causes a decrease in the amount of blood the heart pumps with each heartbeat. The amount of blood ejected from the heart with each contraction is called the left ventricular ejection fraction (LVEF), or simply ejection fraction (EF). A weakened heart may have a lower EF which can cause fatigue and low blood pressure due to less blood flow to the body, and can cause swelling in legs and abdomen due to fluid buildup in organs including the lungs and liver. 

How is it diagnosed?

PPCM may be difficult to detect because symptoms of heart failure can mimic those of pregnancy, such as shortness of breath and swelling in the feet and legs. Any new shortness of breath, especially at rest, or swelling that occurs after delivery or sudden onset of these symptoms during pregnancy should lead to prompt evaluation. 

During a physical exam, health care professionals will look for signs of fluid in the lungs. They may use an X-ray to see, or a stethoscope to listen for, evidence of fluid in the lungs, a rapid heart rate or abnormal heart sounds. A heart ultrasound, called an echocardiogram, can detect cardiomyopathy by showing that the heart function is weak. Lab tests may also be done to confirm the diagnosis.

PPCM is diagnosed when the following three criteria are met:

  1. Heart failure develops in the last month of pregnancy or within months following delivery.
  2. Heart pumping is reduced, with a left ventricular ejection fraction less than 45% (typically measured by an echocardiogram). A normal LVEF is between 50% and 70%.
  3. No other cause for heart failure can be found.

Laboratory blood tests are a standard part of the evaluation. This includes tests to assess kidney, electrolytes, liver, thyroid function and a complete blood count to look for anemia or evidence of infection. Other blood tests, brain natriuretic peptide (BNP) and N-terminal pro-BNP levels may be done to evaluate cardiac injury, stress and level of risk.

Symptoms of the condition include:

  • Shortness of breath or breathlessness with light activity and when lying flat
  • Fatigue
  • Fluid retention which causes swollen ankles or feet, cough, chest congestion and increased urination at night.
  • Chest pain or tightness
  • Sensation of heart racing or skipping beats (palpitations), lightheadedness or almost fainting.

It's important to talk to a health care professional if you are concerned that you have symptoms of PPCM. 

What are the causes?

The underlying cause is unclear, and likely involves several factors. Research suggests that PPCM may be triggered by prior viral illness, nutritional deficiency, hemodynamic stress during pregnancy or an abnormal immune response. These causes have not been proven.

More recent research suggests that PPCM may be caused by the overactivity of certain hormones that cause damage to the vascular system. These hormone levels have been found to be higher in women with preeclampsia, which could help explain why they are at higher risk of developing PPCM. It is not clear why some women may be more predisposed to the effects of these hormones than others. Genetics or family history may also play a role, although most women who develop PPCM have no family history of cardiomyopathy.

Several risk factors include:

  • Maternal age of 35+
  • High blood pressure, including preeclampsia or gestational hypertension
  • Multiple gestations (e.g., twins)
  • PPCM is more common in patients who identify as Black, though it is not understood how race plays a role in the development of PPCM

How can PPCM be treated?

The goal of peripartum cardiomyopathy treatment is to improve heart function and keep extra fluid from collecting in the lungs or other parts of your body. With medical therapy, many women with PPCM recover normal heart function within the first three to six months of treatment. A small number of patients with PPCM will develop severe heart failure requiring mechanical heart pumps or heart transplant.

A physician can prescribe several classes of medications to treat symptoms and help the heart function recover. The following medications are commonly used to treat heart failure. However, health care professionals will be cautious about using the medications as some are harmful if your are pregnant or breastfeeding.

  • Angiotensin converting enzyme (ACE) inhibitors/angiotensin receptor blockers (ARBs) – Lower blood pressure and helps the heart work more efficiently.
  • Angiotensin receptor/neprilysin inhibitor (ARNI) – Lower blood pressure and makes it easier for the heart to pump blood.
  • Beta blockers – Cause the heart to beat more slowly so it has recovery time.
  • Diuretics – Reduce fluid retention.
  • Digitalis – Strengthens the pumping ability of the heart, but due to narrow safety margins with the need to monitor levels, it is not frequently used. 
  • Anticoagulants – Help thin the blood. Patients with PPCM are at increased risk of developing blood clots, especially if the ejection fraction is very low.
  • Inotropic therapies – Used in intensive care and for advanced heart failure to help the heart beat stronger.
  • Bromocriptine – Blocks the release of prolactin, a hormone that promotes lactation. Bromocriptine may help the heart recover, but the recommendations for use are not specific. Additional research is needed to understand if bromocriptine should be prescribed for patients with severe PPCM.

Health care professionals may recommend a low-salt diet, fluid restrictions and measurements of daily weight. A weight gain of 3 pounds or more over a day or two may signal a fluid buildup.

Women who smoke and drink alcohol will be advised to stop, because these habits make the condition worse.  

How can women minimize their risk?

Woman can manage their health to decrease the risk of high blood pressure. Don’t smoke. Eat a well balance diet, avoid alcohol and move daily for exercise and to support a healthy heart. Some of the risk factors for PPCM are not modifiable, such as race and genetics. Women who develop peripartum cardiomyopathy are at high risk of developing the same condition with future pregnancies, if the heart function is not fully recovered. You and your health care professional might consider options for contraception if you want to avoid an unplanned pregnancy.