Peripartum cardiomyopathy

Infobox_Disease
Name = Peripartum cardiomyopathy


Caption =
DiseasesDB = 29243
ICD10 = ICD10|O|90|3|o|85
ICD9 = ICD9|674.5
ICDO =
OMIM =
MedlinePlus =
eMedicineSubj = med
eMedicineTopic = 292
MeshID =

Peripartum cardiomyopathy (PPCM) is a form of dilated cardiomyopathy that is defined as deterioration in cardiac function presenting typically between the last month of pregnancy and up to five months postpartum. As with other forms of dilated cardiomyopathy, PPCM involves systolic dysfunction of the heart with a decrease of the left ventricular ejection fraction (EF) with associated congestive heart failure and an increased risk of atrial and ventricular arrhythmias, thromboembolism (blockage of a blood vessel by a blood clot), and even sudden cardiac death. In essence, the heart muscle cannot contract forcefully enough to pump adequate amounts of blood for the needs of the body's vital organs.Pearson GD, Veille JC, Rahimtoola S, Hsia J, Oakley CM, Hosenpud JD, Ansari AA, Baughman KL. Peripartum cardiomyopathy. National Heart, Lung, and Blood Institute and Office of Rare Diseases (National Institutes of Health) Workshop recommendations and review. JAMA 2000; 283:1183-88.] Elkayam U, Akhter MW, Singh HS, Khan S, Bitar F, Hameed A, Shotan A.Pregnancy-associated cardiomyopathy: clinical characteristics and a comparison between early and late presentation. Circulation 2005; 111:2050-55.] Sliwa K, Fett JD, Elkayam U. Seminar: Peripartum cardiomyopathy. Lancet 2006; 368:687-93.] Murali S, Baldisser MR. Peripartum cardiomyopathy.Crit Care Med 2005 Oct; 33 (10 Suppl): S340-6.] Phillips SD, Warnes CA. Peripartum cardiomyopathy: current therapeutic perspectives. Curr Treat Options Cardiovasc Med 2004; 6:481-88.]

PPCM is a diagnosis of exclusion, wherein patients have no prior history of heart disease and there are no other known possible causes of heart failure. Echocardiogram is used to both diagnose and monitor the effectiveness of treatment for PPCM.

The cause of PPCM is unknown. Currently, researchers are investigating cardiotropic viruses, autoimmunity or immune system dysfunction, other toxins that serve as triggers to immune system dysfunction, micronutrient or trace mineral definciencies, and genetics as possible components that contribute to or cause the development of PPCM.Ansari AA, Fett JD, Carraway RD, Mayne AE, Onlamoon M, Sundstrom JB. Autoimmune mechanisms as the basis for human peripartum cardiomyopathy. Clinical Review Allergy Immunology 2002; 23:289-312.]

The process of PPCM begins with an unknown trigger (possibly a cardiotropic virus or other yet unidentified catalyst) that initiates an inflammatory process in the heart. Consequently, heart muscle cells are damaged; some die or become scar tissue. Scar tissue has no ability to contract; therefore, the effectiveness of the pumping action of the heart is decreased. Also, damage to the cytoskeletal framework of the heart causes the heart to enlarge, stretch or alter in shape, also decreasing the heart's systolic function or output. The initial inflammatory process appears to cause an autoimmune or immune dysfunctional process, which in turn fuels the initial inflammatory process. Progressive loss of heart muscle cells leads to eventual heart failure.Fett, JD. Understanding peripartum cardiomyopathy, 2008. Int J Cardiol. 2008 Jun 28. (Epub ahead of print)]

Prevalence

It is estimated that the incidence of PPCM in the United States is between 1 in 2000 to 4000 live births.Mielniczuk LM, Williams K, Davis DR, et al. Frequency of peripartum cardiomyopathy. Am J Cardiol 2006; 97:1765-68.] Fett JD, Christie LG, Carraway RD, Murphy JG. Five-year prospective study of the incidence and prognosis of peripartum cardiomyopathy at a single institution. Mayo Proceed 2005; 80: 1602-06.] While it can affect women of all races, it is more prevalent in some countries; for example, estimates suggest that PPCM occurs at rates of one in 1000 live births in South African Bantus, and as high as one in 300 in Haiti.Desai D, Moodley J, Naidoo D. Peripartum cardiomyopathy: experiences at King Edward VIII Hospital, Durban, South Africa and a review of the literature. Top Doct 1995; 25: 118-23.]

Some studies assert that PPCM may be slightly more prevalent among older women who have had higher numbers of liveborn children and among women of older and younger extremes of childbearing age. However, a quarter to a third of PPCM patients are young women who have given birth for the first time.Sliwa K, Forster O, Libhaber E, Fett J, Sundstrom JB, Hilfiker-Kleiner D, Ansari AA. Peripartum cardiomyopathy: inflammatory markers as predictors of outcome in 100 prospectively studied patients. European Heart Journal. 2006; 27(4):441-6.] Sliwa K, Skudicky D, Bergemann A, Cnady G, Puren A, Sareli P. Peripartum cardiomyopathy: analysis of clinical outcome, left ventricular function, plasma levels of cytokines and Fas/Apo-1. J Am Coll Cardiol 2000; 35: 701-05.]

While the use of tocolytic agents or the development of preeclampsia (toxemia of pregnancy) and pregnancy-induced hypertension (PIH) may contribute to the worsening of heart failure, they do not cause PPCM; the majority of women have developed PPCM who neither received tocolytics nor had preeclampsia nor PIH.

In short, PPCM can occur in any woman of any racial background, at any age during reproductive years, and in any pregnancy.Elkayam U, Padmini P, Tummala P, Rao K, Akhter MW, Karaalp IS, Wani OR, Hameed A, gviazda I, Shotan A. Maternal and fetal outcomes of subsequent pregnancies in women with peripartum cardiomyopathy. New England Journal Medicine 2001;344:1567-71.]

Clinical Features

Symptoms usually include one or more of the following: orthopnea (difficulty breathing while lying flat), dyspnea (shortness of breath on exertion), pitting edema (swelling), cough, frequent night-time urination, excessive weight gain during the last month of pregnancy (two to four or more pounds per week), palpitations (sensation of racing heart-rate, skipping beats, long pauses between beats, or fluttering), and chest pain.

The shortness of breath is often described by PPCM patients as the inability to take a deep or full breath or to get enough air into the lungs. Also, patients often describe the need to prop themselves up overnight by using two or more pillows in order to breathe better. These symptoms, swelling, and/or cough may be indications of pulmonary edema (fluid in the lungs) resulting from acute heart failure and PPCM.

Unfortunately, patients and clinicians sometimes dismiss early symptoms because they appear to be typical of normal pregnancy. Yet, early detection and treatment are critically important to the patient with PPCM. Delays in diagnosis and treatment of PPCM are associated with increased morbidity and mortality.Fett JD, Christie LG, Carraway RD, Sundstrom JB, Ansari AA, Murphy JG. Unrecognized peripartum cardiomyopathy in Haitian women. International Journal Gynaecology Obstetrics 2005; 90:161-6.]

It is important to note that occasionally patients present with other signs or symptoms. This is demonstrated by one report of a woman with liver failure five weeks postpartum who was being considered for liver transplant. An echocardiogram was performed and revealed PPCM and heart failure as the cause of her severe liver failure. Conventional heart failure medications were administered. She survived and completely recovered from both the liver failure and PPCM.Fussell KM, Awad JA, Ware LB. Case of fulminant hepatic failure due to unrecognized peripartum cardiomyopathy. Crit Care Med 2005; 33: 891-93.]

It is also quite common for women to present with evidence of having an embolus (clot) passing from the heart to a vital organ, causing such complications as stroke, loss of circulation to a limb, even coronary artery occlusion (blockage) with typical myocardial infarction (heart attack).Lasinska-Kowara, et al. Two cases of postpartum cardiomyopathy initially misdiagnosed for pulmonary embolism. Canadian J Anesthesia 2001; 48:773-777.]

For these reasons, it is paramount that clinicians hold a high suspicion of PPCM in any peri- or postpartum patient where unusual or unexplained symptoms or presentations occur.

The following is a screening tool [http://www.amothersheart.org/members/showthread.php?t=5124] developed by James D. Fett, MD, which may be useful to patients and medical professionals in determining the need to take further action to diagnose symptoms:

Prognosis

The most recent studies indicate that with newer conventional heart failure treatment consisting of diuretics, ACE inhibitors and beta blockers, the survival rate is very high at 95% or better and almost all PPCM patients improve with treatment.Felker GM, Jaeger CJ, Klodas E, Thiemann DR, Hare JM, Hruban RH, Kasper EK, Baughman KL. Myocarditis and long-term survival in peripartum cardiomyopathy. American Heart Journal 2000;140:785-91.] Amos AM, Jaber WA, Russell SD. Improved outcomes in peripartum cardiomyopathy with contemporary treatments. American Heart Journal 2006;152:509-13.] McNamara. Left ventricular recovery in peripartum cardiomyopathy: Impact of beta-blockade. Circulation 2007; 116, October 16, Supplement II, page 551, Abstract #2500.] In the United States, over 50% of PPCM patients experience complete recovery of heart function (EF greater than 50%). Almost all recovered patients are eventually able to discontinue medications with no resulting relapse and have normal life expectancy.

It is a misconception that hope for recovery depends upon improvement or recovery within the first six to 12 months of diagnosis. Many women continue to improve or recover even years after diagnosis with continued medicinal treatment. Once fully recovered, if there is no subsequent pregnancy, the possibility of relapse or recurrence of heart failure is minimal.

Subsequent pregnancy should be avoided when left ventricular function has not recovered and the EF is 50% or lower. However, many women who have fully recovered from PPCM have gone on to have successful subsequent pregnancies. A significant study reports that the risk for recurrence of heart failure in recovered PPCM patients is approximately 21% or better. The chance of relapse may be even smaller for those with normal contractile reserve as demonstrated by stress echocardiography.Lampert MB, Lynn Weinert BS, Hibbard J, Korcarz C, Lindheimer M, Lang RM. Contractile reserve in patients with peripartum cardiomyopathy and recovered left ventricular function. Am J Obstet Gynecol 1997; 176:189-95.] Dorbala S, Brozena S, Zeb S, Galatro K, Homel P, Ren JF, Chaudhry FA. Risk stratification of women with peripartum cardiomyopathy at initial presentation; a dobutamine stress echocardiography study. J Am Soc Echocardiogr 2005; 18:45-8.] In any subsequent pregnancy, careful monitoring is necessary. Where relapse occurs, conventional treatment should be resumed, including hydralazine with nitrates plus beta-blockers during pregnancy, or ACE-inhibitors plus beta-blockers following pregnancy.

Treatment and Support

Early detection and treatment are associated with higher rates of recovery and decreased morbidity and mortality.

Treatment for PPCM is similar to treatment for congestive heart failure. Conventional heart failure treatment includes the use of diuretics, beta blockers (B-B), and angiotensin-converting enzyme inhibitors (ACE-I) after delivery. Diuretics, preferably furosemide, help the body to get rid of excess water weight and also lower blood pressure. ACE-I and B-B improve blood circulation and contribute to the reversal of the immune system dysfunction associated with PPCM. If ACE-I is not well tolerated by the patient, it can be replaced by angiotensin receptor blockers (ARB). Hydralzine with nitrates may replace ACE-I in breastfeeding mothers or before delivery; however, evidence suggests that this course of treatment may not be as effective as ACE-I but beneficial when necessary.

If EF is less than 35%, anticoagulation is indicated, as there is a greater risk of developing left ventricular thrombi (blood clots). Sometimes implantation of a left ventricular assist device (LVAD) or even heart transplant also becomes necessary.Aziz TM, Burgess MI, Acladious NN, et al. Heart transplantation for peripartum cardiomyopathy: a report of three cases and a literature review. Cardiovasc Surg 1999; 7:565-67.]

It is important that the patient receives regular follow-up care including frequent echocardiograms to monitor improvement or the lack thereof, particularly after changes of medical treatment regimes.

Patients who do not respond to initial treatment, defined as left ventricular EF remaining below 20% at two months or below 40% at three months with conventional treatment may merit further investigation, including cardiac magnetic resonance imaging (MRI), cardiac catheterization, and endomyocardial biopsy for special staining and for viral polymerase chain reaction (PCR) analysis. Antiviral therapy, immunoabsorption, intravenous gamma globulin, or other immunomodulation therapy may then be considered accordingly, but following a controlled research-type protocol.

Since no one knows for sure exactly when to discontinue treatment, even when recovery occurs quickly, it is still recommended that both ACE-I and B-B be continued for at least one year after diagnosis.

Emotional as well as educational support may be helpful to the PPCM patient. The non-profit online organization, "A Mother’s Heart", found at http://www.amothersheart.org, claims to provide the most up-to-date medical information regarding PPCM as well as the largest online PPCM support group worldwide, which can be accessed at http://www.amothersheart.org/members/index.php.

References