Peripartum cardiomyopathy: Difference between revisions
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Revision as of 18:32, 4 June 2012
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Peripartum cardiomyopathy (PPCM) is a form of dilated cardiomyopathy that is defined as a deterioration in cardiac function presenting between the last month of gestation and up to five months post-partum.
As with other forms of dilated cardiomyopathy, PPCM involves decrease of the left ventricular ejection fraction with associated congestive heart failure and increased risk of atrial and ventricular arrhythmias and even sudden cardiac death.
Etiology
The etiology of postpartum cardiomyopathy is not clearly known. Research suggests that cardiac angiogenic imbalance may play a role in peripartum cardiomyopathy.
Cardiac Angiogenic Imbalance and Peripartum Cardiomyopathy
Researchers indicated a two hit combination as the cause of peripartum cardiomyopathy. This includes:[1]
- Systemic anti-angiogenic signals during late pregnancy like elevated sFTL1 from placenta which binds to and neutralize soluble members of the VEGF(vascular Endothelial Growth Factor) family , prolactin from pituitary which on inappropriate cleavage by reactive oxygen species (ROS) forms potent anti-angiogenic 16-kDa form, and excess angiotensin II signalling.
- A host susceptibility marked by insufficient local pro-angiogenic defenses in the heart. This includes:
- A decrease in the transcriptional coactivator PGC-1α. PGC-1α drives mitochondrial biogenesis, regulates angiogenic programming and increases ROS scavenging.
- Abnormal or absent STAT3. STAT3 is responsible for protection against ROS production.
- The host susceptibility may be:
- Genetically predisposed
- Immune activated
- viral infection induced
- auto-antibody induced
- Inflammatory states of the heart induced.
PGC-1α knock out mice were completely rescued from developing peripartum cardiomyopathy by administering VEGF and Bromocriptine which provides strong evidence that cardiac angiogenic imbalance can lead to ultimate onset of peripartum cardiomyopathy.
Risk Factors
In the US the prevalence is estimated to be 1 case per 1300-15,000 live births.
The incidence of peripartum cardiomyopathy is increased in women over the age of 30, in twin pregnancies, in multiparous women, in women with gestational hypertension, those who have received tocolytic therapy, and in african americans.
Clinical Features (History)
Pregnancy itself brings about some features that suggest cardiac insufficiency. Symptoms such as dyspnoea, dizziness, orthopnoea and decreased exercise tolerance are often normal findings in pregnancy.
Moreover, the normal cardiac physiology changes dramatically in the gravid female. Blood volume increases progressively from 6-8 weeks gestation (pregnancy) and reaches a maximum at approximately 32-34 weeks with little change thereafter. During the first trimester cardiac output is 30-40% higher than in the non-pregnant state; there is also an approximately 35% increase in stroke volume, a 15% increase in HR and a steady decrease in vascular resistance.
Since this is excellent cover for a developing condition, often there are no extreme or notable symptoms until several days post-partum when the most notable symptoms become pulmonary edema with resultant breathing difficulties(dysnopea), serious energy depletion performing simple tasks such as walking, standing or even sitting up for extended periods, and sudden cardiac arrest.
If these conditions appear after a woman has been discharged from clinical care the possibility of mortality is greatly increased.
The dyspnoea is described usually by women as the inability to take a deep breath to get enough air into her lungs. It is thought that the hormonally mediated (progesterone) hyperventilation seen in pregnancy is the cause.
In PPCM the symptoms secondary to acute onset of heart failure seen are similar to patients with systolic dysfunction who are not pregnant. These symptoms include cough, orthopnoea, paroxysmal nocturnal dyspnoea, fatigue, palpitations, haemoptysis and chest pain. These symptoms mimic many normal pregnant women who cannot tolerate lying flat, have significant pedal edema, complain of shortness of breath and dyspnea but have no heart disease.
The challenge facing physicians is to differentiate between these two groups and diagnose women with PPCM sooner than later as early intervention has shown benefit and may save lives.
Prognosis
Mortality rates range anywhere between 9% and 56%. About 50 to 60 percent of women with PPCM demonstrate improvement or total recovery in their left ventricular function within 6 months of diagnosis. The remainder tend to have either stabilization of their ventricular function or worsening (requiring cardiac transplantation).1
Women are strongly discouraged form subsequent pregnancies as numerous studies have demonstrated recurrence of the disease.
The New York Peripartum Cardiomyopathy Study Group is an ongoing registry seeking to answer many of the questions left unanswered because of the rarity of the disease. For more information about the study, one can visit [2].
Treatment for this disease varies widely reflecting the range of severity. While some patients with severe left ventricular dysfunction (less than 35%) may proceed to cardiac tranplant or require an automated internal cardiac defibrillator (AICD) and standard heart failure therapy, others may return to normal cardiac function and reuqire little, if any, additional medical therapy. However, all women should be strongly discouraged from having subsequent pregnancies.
Treatment
Treatment for the disease is similar to treatment for congestive heart failure. Delivery is the recommeded overall treatment to decrease the volume load, improve ventricular function and simplify the medical management of these patients.
Additional Resources
- Ravikishore AG, Kaul UA, Sethi KK, Khalilullah M. Peripartum cardiomyopathy: prognostic variables at initial evaluation. Int J Cardiol. 1991 Sep;32(3):377-80. (Medline abstract)
- Ro, Angela; Frishman, William. Cardiology in Review 2006;14: 35–42
References
- ↑ Patten IS, Rana S, Shahul S, Rowe GC, Jang C, Liu L, Hacker MR, Rhee JS, Mitchell J, Mahmood F, Hess P, Farrell C, Koulisis N, Khankin EV, Burke SD, Tudorache I, Bauersachs J, del Monte F, Hilfiker-Kleiner D, Karumanchi SA, Arany Z (2012). "Cardiac angiogenic imbalance leads to peripartum cardiomyopathy". Nature. 485 (7398): 333–8. doi:10.1038/nature11040. PMID 22596155. Retrieved 2012-06-04. Unknown parameter
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