Peripartum Cardiomyopathy

mujer embarazada en la cama

¿Qué es la miocardiopatía periparto?

La miocardiopatía periparto (MCPP), también conocida como "miocardiopatía posparto", es una forma poco común de insuficiencia cardíaca que se manifiesta durante el último mes del embarazo o hasta cinco meses después del parto. El término "miocardiopatía" significa literalmente "enfermedad del músculo cardíaco".

PPCM is a dilated form of the condition when the heart chambers enlarge and the muscle weakens. This causes a decrease in the percentage of blood ejected from the left ventricle of the heart with each contraction. That leads to less blood flow. Then the heart can’t meet the demands of the body’s organs for oxygen, affecting the lungs, liver and other body systems.

PPCM is rare in the United States, Canada, and Europe. About 1,000 to 1,300 women develop the condition in the U.S. each year. PPCM is much more common in some countries and may be related to differences in diet, lifestyle, other medical conditions or genetics.

¿Cómo se diagnostica?

PPCM may be difficult to detect because symptoms of heart failure can mimic those of third trimester pregnancy, such as swelling in the feet and legs, and some shortness of breath. More extreme cases include severe shortness of breath and prolonged swelling after delivery.

During a physical exam, health care professionals will look for signs of fluid in the lungs. They will use a stethoscope to listen for lung crackles, a rapid heart rate or abnormal heart sounds. An echocardiogram can detect cardiomyopathy by showing the diminished functioning of the heart.

La MCPP se diagnostica cuando se cumplen los siguientes tres criterios:

  1. Heart failure develops in the last month of pregnancy or within five months of delivery.
  2. Heart pumping is reduced, with an ejection fraction (EF) less than 45% (typically measured by an echocardiogram). EF is how much blood the left ventricle pumps out with each contraction. A normal EF can be between 55 and 70.
  3. No se observa ninguna otra causa de insuficiencia cardíaca con FE reducida.

Laboratory blood tests are a standard part of the evaluation. This includes tests to assess kidney, liver and thyroid function; tests to assess electrolytes, including sodium and potassium; and a complete blood count to look for anemia or evidence of infection. Markers of cardiac injury and stress can also assess level of risk.

Algunos síntomas de esta afección son:

  • Fatiga
  • Sentir que el corazón late con un ritmo rápido o irregular (palpitaciones)
  • Increased nighttime urination
  • Respiración entrecortada con la actividad y cuando se está recostada
  • Tobillos hinchados
  • Venas del cuello hinchadas
  • Presión arterial baja o caídas de presión al ponerse de pie

The New York Heart Association system classifies the severity of symptoms in patients with PPCM:

  • Clase I: enfermedad sin síntomas
  • Clase II: síntomas leves/con efecto en la función o síntomas solo con esfuerzo extremo
  • Clase III: síntomas con esfuerzo mínimo
  • Clase IV: síntomas en reposo

¿Cuáles son las causas?

The underlying cause is unclear. Heart biopsies in some cases show women have inflammation in the heart muscle. This may be because of prior viral illness or abnormal immune response. Other potential causes include poor nutrition, coronary artery spasm, small-vessel disease and defective antioxidant defenses. Genetics may also play a role.

Initially thought to be more common in women older than 30, PPCM has since been reported across a wide range of age groups. Several risk factors include:

  • Edad materna avanzada
  • History of cardiac disorders, such as heart attack, heart valve dysfunction or myocarditis (inflammation of the heart muscle)
  • Exposure to toxins, such as alcohol or chemotherapy
  • Hipertensión arterial
  • Embarazos múltiples
  • Multifetal pregnancy (i.e., twins)
  • Use of certain medications to prevent premature labor
  • African descent
  • Poor nutrition

¿Cómo se puede tratar la MCPP?

El objetivo del tratamiento de la miocardiopatía periparto es evitar que se acumule líquido adicional en los pulmones y contribuir a que el corazón se recupere de la mejor forma posible. Muchas mujeres recuperan la función cardíaca normal o se estabilizan con medicamentos. Algunas desarrollan una insuficiencia cardíaca grave que requiere asistencia mecánica o trasplante cardíaco.

A physician can prescribe several classes of medications to treat symptoms, with variations that are safer for women who are breastfeeding.

  • Angiotensin converting enzyme (ACE) inhibitors – Help the heart work more efficiently
  • β bloqueantes: hacen que el corazón lata más lentamente para que tenga tiempo de recuperación.
  • Diuréticos: reducen la retención de líquidos.
  • Digitálicos: un grupo de sustancias derivadas de la planta dedalera que se usan desde hace más de 200 años para tratar la insuficiencia cardíaca. Los digitálicos fortalecen la capacidad de bombeo del corazón.
  • Anticoagulantes: favorecen la dilución de la sangre. Las pacientes con MCPP tienen un mayor riesgo de desarrollar coágulos, sobre todo si la FE es muy baja.

Health care professionals may recommend a low-sodium diet, fluid restrictions or daily weighing. A weight gain of 3 to 4 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 may make the symptoms worse.

A heart biopsy may help determine if the underlying cause of cardiomyopathy is a heart muscle infection (myocarditis). But this procedure is uncommon.

¿Cómo pueden minimizar el riesgo las mujeres?

Para desarrollar y mantener un corazón fuerte, las mujeres deben evitar los cigarrillos y el alcohol, consumir una dieta equilibrada y hacer ejercicio de forma habitual. Las mujeres que desarrollan miocardiopatía periparto presentan un elevado riesgo de desarrollar la misma afección en embarazos posteriores.

Posibles avances futuros

Ongoing studies continue to help researchers better understand the cause of PPCM and develop new treatments. Health care professionals have tried treatments that alter the immune system, such as intravenous γ-globulin and immunoabsorption, but they’re not proven. Researchers also have focused on the role of prolactin in PPCM. Prolactin is a hormone released from the pituitary gland late in pregnancy and after delivery that stimulates breast milk production. But prolactin may have adverse effects on the heart muscle by limiting its blood supply and causing cell death. Bromocryptine is a medication that inhibits the pituitary secretion of prolactin. Early studies suggest it helps treat PPCM, but more research is needed.