Peripartum cardiomyopathy is an uncommon disorder associated with pregnancy in which the heart dilates and weakens, leading to symptoms of heart failure.
Peripartum cardiomyopathy may be difficult to diagnose because symptoms of heart failure can mimic those of pregnancy.
Affected women may recover normal heart function, stabilize on medicines, or progress to severe heart failure requiring mechanical support or heart transplantation. Even when the heart recovers, another pregnancy may be associated with a risk of recurrent heart failure.
Important research is underway to understand the cause of peripartum cardiomyopathy and to develop new treatments.
Medications are used to stabilize heart function, to improve blood flow to vital organs, and to reduce fluid overload. They can also be used to prevent or treat complications such as blood clot formation and abnormal heart rhythms. The choice and safety of medications depends on whether the patient presents during or after pregnancy.
Vasodilators: these medications relax blood vessels, making it easier for the heart to eject blood, and lower pressures in the heart and lungs.
During pregnancy, the vasodilator of choice is Hydralazine, which can be given alone or with nitrates.
After pregnancy, angiotensin-converting enzyme ( ACE ) inhibitors or angiotensin receptor blockers can be used safely in place of Hydralazine / nitrates and may help the heart to heal.
ACE inhibitors or angiotensin receptor blockers should not be taken during pregnancy because they can cause birth defects.
Vasodilators can lower blood pressure and may be associated with lightheadedness or fatigue.
Diuretics: these medications cause the kidneys to excrete salt and water and help to relieve symptoms related to fluid retention such as shortness of breath, abdominal bloating, and edema.
Diuretics can also lower blood pressure and lead to loss of potassium, causing muscle cramps and dehydration. Blood pressure, kidney function, and electrolytes should be monitored while on diuretic therapy.
Beta-blockers: patients with peripartum cardiomyopathy and heart failure have increased levels of catecholamines ( adrenaline and related hormones ), which can increase heart rate, blood pressure, and overall heart and vascular stress.
Beta-blockers are used to block these effects and can result in decreased heart rate and blood pressure. Over time, beta-blockers help the heart to heal and recover normal ejection fraction.
They also protect the heart against abnormal heart rhythms.
Certain beta-blockers are safer than others during pregnancy.
Digitalis: Digitalis is derived from the foxglove plant and has been used for more than 200 years to treat heart failure. Digitalis strengthens the pumping ability of the heart and may lower stimulation of catecholamines.
Digitalis can also be used to slow the heart rate in patients with atrial fibrillation.
Digitalis can be used safely during and after pregnancy with the monitoring of blood levels.
Spironolactone: like ACE inhibitors, Spironolactone can be used safely after pregnancy to treat heart failure and to help the heart to heal.
Spironolactone is a mild diuretic that causes the kidneys to retain potassium, so kidney function and potassium levels need to be monitored during therapy.
Anticoagulants: patients with peripartum cardiomyopathy are at increased risk of developing blood clots, especially if the ejection fraction is very low. In these cases, medications are used to thin the blood.
During pregnancy, Heparin can be given as an injection under the skin or as a continuous intravenous infusion. After pregnancy, Warfarin can be taken safely as a pill once a day. Like ACE inhibitors, Warfarin should not be taken during pregnancy because of the risk of birth defects. Both Heparin and Warfarin require close monitoring of blood clotting parameters to avoid bleeding.
Antiarrhythmics: in patients who experience arrhythmias, medications may be needed to stabilize the heart rate and rhythm.
During pregnancy, beta-blockers, Sotalol, and intravenous Procainamide can be used. Amiodarone is a third-line agent that can be given intravenously or orally during or after pregnancy, but it may be toxic to the fetus and requires careful monitoring of liver, thyroid, and lung function.
Some patients with peripartum cardiomyopathy will develop severe symptoms of heart failure and require more aggressive treatment in an intensive care setting.
Intravenous medications, including inotropes to increase the pumping function of the heart and vasodilators and diuretics to relieve congestion, are commonly used.
Supplemental oxygen is usually provided by a nasal cannula or face mask, and a catheter may be placed into the heart to monitor pressures and heart output.
For patients who do not respond to these interventions, mechanical support with a balloon pump or temporary heart pump ( sometimes called a ventricular assist device ) may be necessary.
Mechanical support is generally continued until native heart function improves ( bridge to recovery ) or the patient undergoes heart transplantation ( bridge to transplantation ).
In recent reports, heart transplantation was required in only approximately 5% of patients with peripartum cardiomyopathy, with excellent posttransplantation survival. ( Xagena )
Givertz MM, Circulation 2013; 127: e622-e626