Peripartum cardiomyopathy
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Associate Editor(s)-in-Chief: Nabeel Ahmad
Synonyms and keywords: Meadows syndrome
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. The definition of PPCM includes four criteria, three clinical and one echocardiographic:[1] PPCM occurs during last month of pregnancy or first five months after delivery, absence of an identifiable cause for cardiac failure, absence of heart disease prior to last five months of pregnancy, echocardiographic criteria -severe left ventricular systolic dysfunction, demonstrated by ejection fraction less than 45% or M-mode fractional shortening less than 30%(or both) and left ventricular end-diastolic dimension >2.7cm/m².
Pathophysiology
The etiology of peripartum 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:[2]
- Systemic anti-angiogenic signals during late pregnancy like elevated sFTL1 ( soluble fms - like tyrosine kinase-1 ) from the placenta which binds to and neutralizes soluble members of the VEGF(vascular Endothelial Growth Factor) family , elevated prolactin from the pituitary which on inappropriate cleavage by reactive oxygen species (ROS) forms a potent anti-angiogenic 16-kDa form, and excess angiotensin II signalling.
- A host susceptibility caused 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.
- Genetically predisposed
- Immune activated
- viral infection induced
- auto-antibody induced
- Inflammatory states of the heart induced.
PGC-1α knockout mice (mice in which all or part of gene was eliminated or inactivated by genetic engineering) 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.
- Significant hemodynamic changes occur during pregnancy. Which can increase in preload secondary to the increase in red blood cell mass and blood volume.
- Which increases the cardiac output by 20% to 30% due to an increase in heart rate and stroke volume by 15% to 25%.
- All these changes present during the first and second trimester , it is not clear that hemodynamic stresses are the main reason for PPCM.[3]
- Other etiologies such as myocarditis has been hypothesized due to the presence of viral genomes in biopsy of patients with PPCM as echo virus, Coxsackie, and parvovirus B19.
- Genetic factors also have been implicated in the etiology of PPCM. Evidence of cluster of families with PPCM has been observed, and it is possible that the expression of the genes with the toxic environment during late pregnancy due to oxidative stress can increase the susceptibility of PPCM.[4]
- A pro-inflammatory state might play a role in the development of PPCM. Increased levels of cytokines such as TNF-alpha and interleukin-6 have been found in patients with PPCM and heart failure.[5]
Clinical Features
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 an 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(dyspnea), 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.
The following is a screening tool 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:[6]
| Focused medical history for PPCM screening, looking for early symptoms of heart failure, during last month of pregnancy: |
|---|
| 1. Orthopnea (difficulty breathing while lying flat): |
| a.) None = 0 points; b.) Need to elevate head = 1 point; c.) Need to elevate upper body 45° or more = 2 points |
| 2. Dyspnea (shortness of breath on exertion): |
| a.) None = 0 points; b.) Climbing 8 or more steps = 1 point; c.) Walking on level = 2 points |
| 3. Unexplained cough: |
| a.) None = 0 points; b.) Night-time = 1 point; c.) Day and night = 2 points |
| 4. Swelling (pitting edema) lower extremities: |
| a.) None = 0 points; b.) Below knee = 1 point; c.) Above and below knee and/or hands/face = 2 points. |
| 5. Excessive weight gain during last month of pregnancy: |
| a.) Under 2 pounds per week = 0 points; b.) 2 to 4 pounds per week = 1 point; c.) over 4 pounds per week = 2 points. |
| 6. Palpitations (sensation of irregular heart beats): |
| a.) None = 0 points; b.) When lying down at night = 1 point; c.) Day and night, any position = 2 points |
| Scoring and Action: |
| 0 - 2 = low risk—continue observation |
| 3 - 4 = mild risk—consider doing blood BNP and CRP; echocardiogram if BNP and CRP are elevated |
| 5 or more = high risk—do blood BNP, CRP, and echocardiogram |
Differentiating [disease name] from other Diseases
- peripartum cardiomyopathy must be differentiated from other diseases by exclusion, such as:
- Pre-existing idiopathic dilated cardiomyopathy unmasked by pregnancy
- HIV/AIDS cardiomyopathy
- Pre-existing familial dilated cardiomyopathy unmasked by pregnancy
- Pre-existing valvular heart disease unmasked by pregnancy
- Hypertensive heart disease
- Pre-existing unrecognized congenital heart disease
Epidemiology and Demographics
The reported incidence fluctuates globally but is higher in developing countries. It usually affects 1 in 300 to 1 in 3000 pregnancies. Nigeria(1%) and Haiti(0.3%) are examples of geographic hot spots of high incidence. In the United States, the incidence ranges between 1 in 3000 to 1 in 4000 deliveries.[7]
Risk Factors
The incidence of peripartum cardiomyopathy is increased in women
- African descent
- Age greater than 30 years
- Multiparity
- A history of preeclampsia, eclampsia, or postpartum hypertension
- Pregnancy with multiple fetuses
- Those who have received tocolytic therapy
- In maternal cocaine abuse
- Gestational hypertension
Natural History, Complications and 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).[8]
Women are strongly discouraged from 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 [9]
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 transplant or require an automated internal cardiac defibrillator (AICD) and standard heart failure therapy, others may return to normal cardiac function and require little, if any, additional medical therapy. However, all women should be strongly discouraged from having subsequent pregnancies.
Diagnosis
The diagnosis of PPCM has been based upon four clinical criteria
- Development of cardiac failure in the last month of pregnancy or within five months of delivery.
- Absence of an identifiable cause for the cardiac failure.
- Absence of recognizable heart disease prior to the last month of pregnancy.
- Left ventricle systolic dysfunction.[10] EKG findings :
- EKG findings include sinus tachycardia
- Nonspecific ST and T wave abnormalities
- Q waves are occasionally present
- PR and QRS intervals may also be prolonged Electrocardiography finding :
- Overall reduction in contractility
- Left ventricle enlargement without hypertrophy
- Left ventricle ejection fraction <45 percent or fractional shortening <30 percent plus
- Left ventricle end-systolic dimension greater than 2.7 cm/m2
- Regional heterogeneities of systolic wall thickening
- Left atrial enlargement
- Mitral and tricuspid regurgitation
- Small pericardial effusion Chest X-ray :
- The chest x-ray shows enlargement of the heart with pulmonary venous congestion
- Interstitial edema
- Pleural effusions
Echocardiography
Peripartum cardiomyopathy is diagnosed only when the following criteria are met: left ventricular ejection fraction (LVEF) <0.45 or M-mode fractional shortening <30% (or both) and end-diastolic dimension >2.7 cm/m².
Echocardiography is essential for diagnosis. It is effective and obviates the need for cardiac catheterization.[11]
It is also useful to diagnose mural thrombus, mitral regurgitation, tricuspid regurgitation and pericardial effusion.
Prompt echocardiography in all symptomatic pregnant patients can help to reveal patients with undiagnosed peripartum cardiomyopathy earlier in the course of the disease, thereby leading to earlier institution of care and to improvement of outcomes.
Treatment
Treatment for the disease is similar to treatment for congestive heart failure apart from concerning the adverse effect of treatment on fetus or breast-feeding infant.
Delivery is the recommended overall treatment to decrease the volume load, improve ventricular function and simplify the medical management of these patients.
- The goal of treatment for patients with PPCM, optimizing the preload or volume status is done through appropriate diuresis and keeping a balance of intra- and extravascular volume.
- Fluid restriction is fundamental to achieve this goal. Prepartum PCCM has special considerations for treatment due to side effects of medication that cross the placenta and affect the fetus. As an example, use of diuretics during pregnancy should be give in very low doses as they impair perfusion of the placenta and cause potential harm to the fetus. Both hydrochlorothiazide and furosemide are safe during pregnancy and lactation, with close monitoring for diuresis and at low doses.
- Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are contraindicated during pregnancy due to the well known teratogenic effects if administrated during pregnancy.
- Beta-blockers can be used with caution during pregnancy (beta-1 selective agents are preferred) and are contraindicated during breastfeeding because this is excreted in the breast milk. Carvedilol is a combined beta-blocker with an additional alpha-blockade effect that allows a decrease of the afterload and is effective in the treatment of PPCM.
- Hydralazine, a vasodilator, is safe during pregnancy. A nitroglycerin drip can be used to manage afterload in the acute setting. Nitroprusside is contraindicated during pregnancy for concern of cyanide's toxicity.
- In very ill patients with hemodynamic instability, the use of inotropes might be necessary. Use of inotropes such as dobutamine, dopamine, and milrinone is restricted for this critical situation with close monitoring and with fast weaning off medication if possible.
- Digoxin is another drug that can be used for the treatment of PPCM. It is safe during pregnancy and can be used when the ionotropic and chronotropic effect is necessary, especially in the uncontrolled atrial fibrillation.
- Anticoagulation therapy in patients with PPCM is controversial. As a general recommendation, patients with PPCM without LV thrombus or atrial fibrillation should not be in anticoagulation. Patients with PPCM and atrial fibrillation and/or LV thrombus should be anticoagulated according to the guidelines for anticoagulation and the trimester of pregnancy.
- Decisions regarding the use of an implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy in patients with PPCM should consider the natural history of these diseases, including the potential for the recovery of ventricular function.
- Use of mechanical circulatory support has been describing in patients with fulminant PPCM. Placement of left ventricular asistant device (LVAD) can be a bridge for transplant or recovery.
References
- ↑ Shaikh N (2010). "An obstetric emergency called peripartum cardiomyopathy!". Journal of Emergencies, Trauma, and Shock. 3 (1): 39–42. doi:10.4103/0974-2700.58664. PMC 2823141. PMID 20165720. Retrieved 2012-06-05. Unknown parameter
|month=ignored (help) - ↑ 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
|month=ignored (help) - ↑ Rodriguez Ziccardi M, Siddique MS. PMID 29489231. Missing or empty
|title=(help) - ↑ Elkayam U (October 2014). "Risk of subsequent pregnancy in women with a history of peripartum cardiomyopathy". J. Am. Coll. Cardiol. 64 (15): 1629–36. doi:10.1016/j.jacc.2014.07.961. PMID 25301468.
- ↑ Okeke T, Ezenyeaku C, Ikeako L (July 2013). "Peripartum cardiomyopathy". Ann Med Health Sci Res. 3 (3): 313–9. doi:10.4103/2141-9248.117925. PMC 3793431. PMID 24116305.
- ↑ Fett JD (2011). "Validation of a self-test for early diagnosis of heart failure in peripartum cardiomyopathy". Critical Pathways in Cardiology. 10 (1): 44–5. doi:10.1097/HPC.0b013e31820b887b. PMID 21562375. Retrieved 2012-06-05. Unknown parameter
|month=ignored (help) - ↑ Pearson GD, Veille JC, Rahimtoola S, Hsia J, Oakley CM, Hosenpud JD, Ansari A, Baughman KL (2000). "Peripartum cardiomyopathy: National Heart, Lung, and Blood Institute and Office of Rare Diseases (National Institutes of Health) workshop recommendations and review". JAMA : the Journal of the American Medical Association. 283 (9): 1183–8. PMID 10703781. Retrieved 2012-06-05. Unknown parameter
|month=ignored (help) - ↑ Ravikishore AG, Kaul UA, Sethi KK, Khalilullah M (1991). "Peripartum cardiomyopathy: prognostic variables at initial evaluation". International Journal of Cardiology. 32 (3): 377–80. PMID 1838741. Unknown parameter
|month=ignored (help);|access-date=requires|url=(help) - ↑ http://amothersheart.org/PRiCELESS.htm
- ↑ Elkayam U, Akhter MW, Singh H, Khan S, Bitar F, Hameed A, Shotan A (April 2005). "Pregnancy-associated cardiomyopathy: clinical characteristics and a comparison between early and late presentation". Circulation. 111 (16): 2050–5. doi:10.1161/01.CIR.0000162478.36652.7E. PMID 15851613.
- ↑ Bhakta P, Biswas BK, Banerjee B (2007). "Peripartum cardiomyopathy: review of the literature". Yonsei Medical Journal. 48 (5): 731–47. doi:10.3349/ymj.2007.48.5.731. PMC 2628138. PMID 17963329. Retrieved 2012-06-05. Unknown parameter
|month=ignored (help)