Basics
Description
- Dilated cardiomyopathy occurring during the last month of pregnancy up to 5 mo following the delivery
- Diagnostic criteria (all required):
- Onset of myocardial failure during last month of pregnancy or 1st 5 mo after delivery
- Absence of a specific cause
- Absence of prior cardiac disease
- Diagnosis requires strict criteria of echocardiographic dysfunction
- Incidence: 3-5/10,000 live births
- ~50% of cases resolve spontaneously
- Mortality: 18-56%
- Risk factors:
- Older women (>30 yr)
- Multiparous women
- Multiple gestations
- Prolonged tocolytic therapy (>4 wk)
- Obesity
- Preeclampsia
- African American
- Systemic and pulmonary embolism more frequent than with other forms of cardiomyopathy
- Factors indicating a poor prognosis:
- Lower left ejection fraction at 6 mo postpartum
- Onset >2 wk postpartum
- Age >30 yr
- African American descent
- Multiparity
Etiology
Various causes are suggested but remain unproved:
- Viral infection leading to myocarditis in presence of immunosuppression during pregnancy (most likely)
- Immunologic response to an unknown maternal or fetal antigen
- Maladaptive response to the hemodynamic stresses of pregnancy
- Stress-activated cytokines
- Prolonged tocolysis
- Selenium deficiency
Diagnosis
Signs and Symptoms
- Dyspnea
- Dizziness
- Chest pain
- Orthopnea
- Cough
- Paroxysmal nocturnal dyspnea
- Anorexia
- Fatigue
- Arrhythmias
History
- Onset and duration of symptoms
- Unexplained persistent cough
- Excessive weight gain:
- Prior cardiac disease
- Prior pregnancies and complications
Physical Exam
- Palpitations
- Jugular venous distention
- Gallop rhythm
- Mitral regurgitation murmur
- Loud P2
- Pulmonary rales
- Peripheral edema (especially rapid onset)
- Hepatomegaly
- Hepatojugular reflux
Essential Workup
- CXR views:
- Pulmonary venous congestion
- Cardiomegaly (can be difficult to differentiate with pregnancy)
- Pleural effusions
- EKG:
- Nonspecific
- Left ventricular hypertrophy
- Left atrial enlargement
- T-wave flattening or inversion
- Arrhythmias
- Ventricular ectopy (40%)
- Atrial fibrillation (20%)
Diagnosis Tests & Interpretation
Lab
- Electrolytes:
- BUN, creatinine
- CBC:
- Mild postpartum anemia may contribute to fatigue and dyspnea.
- Creatine kinase with muscle and brain fraction
- β-Natriuretic peptide (BNP):
- Useful for distinguishing between heart failure due to diastolic and/or systolic dysfunction and a pulmonary cause of dyspnea
- BNP >100 pg/mL diagnosed heart failure with a sensitivity of 90%, a specificity of 76%, and a predictive accuracy of 83%. BNP of ≤50 pg/mL has a high negative predictive value.
Imaging
- CXR:
- Cardiomegaly
- Effusions (usually right sided)
- 3 phases of pulmonary findings:
- Stage I: Pulmonary redistribution to upper lung fields (cephalization)
- Stage II: Interstitial edema with Kerley B lines
- Stage III: Alveolar edema
- Bilateral confluent perihilar infiltrates leading to classic butterfly pattern
- May be asymmetric and mistaken for pneumonia
- Echo:
- Demonstrates global dilation, cardiac wall thinning, and decreased ejection fraction
- Criteria for the diagnosis were established by Hibbard et al.:
- Ejection fraction <45% or M-mode fractional shortening of <30%
- End-diastolic dimension >2.72 cm/m2
- Exclude valvular pathology and cardiac tamponade.
Diagnostic Procedures/Surgery
Endomyocardial biopsy:
- Indicated to assess for myocarditis and steroid therapy
Differential Diagnosis
- Other causes of dilated cardiomyopathy:
- Ischemia
- Infarction
- Valvular rupture or disease
- Chronic HTN
- Familial
- Toxins:
- Ethanol, anthracyclines, cocaine, drug allergy
- Metabolic:
- Thiamine
- Selenium
- Hypothyroidism
- Thyrotoxicosis
- Hypophosphatemia
- Infectious:
- Viral
- Parasitic or rickettsial
- Bacterial
- Fungal
- Systemic disorders:
- Sarcoidosis
- Scleroderma
- Systemic lupus erythematosus
- Eosinophilic myocarditis
- Neuromuscular dystrophies
- Mitochondrial cardiomyopathies
- Other causes of shortness of breath or edema:
- Pulmonary embolism
- Pneumonia
- Asthma
- Cardiac ischemia
- Anemia
- Hyperthyroidism
- Constrictive pericarditis
- Pericardial tamponade
- Nephrotic syndrome
- Cirrhosis
Treatment
Pre-Hospital
Differentiate pulmonary edema from acute reactive airway disease.
Initial Stabilization/Therapy
ABCs:
- Prompt evaluation of respiratory and hemodynamic status
- Control airway as needed
- Supplemental oxygen
- Continuous positive airway pressure, as needed
- Preload and afterload reduction
Ed Treatment/Procedures
- Antepartum therapy:
- Nitrates
- Hydralazine
- IV furosemide
- Amlodipine: A dihydropyridine calcium channel blocker that has been shown to improve survival in nonischemic cardiomyopathy patients
- Digoxin to control rate due to atrial fibrillation
- Carvedilol (antepartum and not in acute decompensated phase)
- LMWH if EF <35%
- Fetal monitoring
- Invasive cardiac monitoring if unstable
- Postpartum therapy:
- Consider adding ACE inhibitors (enalapril) or ARBs.
- Anticoagulation therapy often recommended:
- 30% of cases complicated by systemic or pulmonary embolism
- During pregnancy, use SC or IV heparin rather than warfarin, which causes birth defects.
- For severe symptoms or lack of response to standard therapy:
- Dobutamine
- Dopamine
- Nitroprusside
- Assist devices
- Intra-aortic balloon pump
- LV assist device
- Extracorporeal membrane oxygenation
- Immunosuppressive therapy:
- Advocated for patients who fail to improve within 2 wk of standard medical therapy
- Prednisone with cyclosporine or azathioprine
- Immunoglobulin therapy remains controversial
Medication
- Amlodipine: 2.5-10 mg/d PO
- Bumetanide: 0.5-2 mg IV
- Digoxin: 0.5 mg IV, then 0.25 mg IV q4h for 2 doses; 0.125-0.375 mg/d PO
- Milrinone: 50 μg/kg over 10 min
- Dobutamine: 2-10 μg/kg/min IV
- Dopamine: 2-20 μg/kg/min IV
- Enalapril: 0.625-1.25 mg IV; 2.5-20 mg/d PO
- Furosemide: 20-100 mg IV
- Metoprolol: 12.5 mg PO BID
- Morphine sulfate: 2-4 mg IV q5min
- Nitroglycerin: 0.4 mg sublingual; 1-2 in of nitroglycerin paste; 5-20 μg/min IV, max. of 100-200 μg/min IV. USE NON-PVC tubing
- Nitroprusside: 0.5-10 μg/kg/min IV
Follow-Up
Disposition
Admission Criteria
- Patients with pulmonary edema, cardiogenic shock, or evidence of ischemia should be admitted to the ICU.
- All symptomatic patients with new onset of peripartum cardiomyopathy should be admitted.
Discharge Criteria
- Mild left ventricular dysfunction
- Established history of peripartum cardiomyopathy:
- Mild fluid overload attributable to excessive salt intake
- Complete resolution of symptoms following ED treatment
- No evidence of cardiac ischemia
- Close follow-up arranged
Issues for Referral
Close follow-up with a cardiologist
Follow-Up Recommendations
- Drink 6-8 glasses of liquid each day.
- Limit salt intake.
- Avoid alcohol because it may worsen cardiomyopathy.
- Support socks may help decrease the swelling in legs and prevent clot formation.
- Daily weights:
- Weight gain can be a sign of extra fluid in the body.
- Call doctor if gain of >2 lb in a day.
- Return for shortness of breath, feeling faint, palpitations.
Pearls and Pitfalls
- Remember high rates of thromboembolism in pregnancy and peripartum cardiomyopathy.
- Utilize multidisciplinary approach with cardiology and obstetrics consultations.
Additional Reading
- Johnson-Coyle L, Jensen L, Sobey A. Peripartum cardiomyopathy: Review and practice guidelines. Am J Crit Care. 2012;21(2):89-98.
- Murali S, Baldisseri MR. Peripartum cardiomyopathy. Crit Care Med. 2005;33:S340-S346.
- Pearson GD, Veille JC, Rahimtoola S, et al. Peripartum cardiomyopathy: National Heart, Lung, and Blood Institute and Office of Rare Diseases (National Institutes of Health) workshop recommendations and review. JAMA. 2000;283:1183-1188.
- Ramaraj R, Sorrell VL. Peripartum cardiomyopathy: Causes, diagnosis, and treatment. Cleve Clin J Med 2009;76(5):289-296.
- Tidswell M. Peripartum cardiomyopathy. Crit Care Clin. 2004;20:777-788.
Codes
ICD9
674.54 Peripartum cardiomyopathy, postpartum condition or complication
ICD10
O90.3 Peripartum cardiomyopathy
SNOMED
- 62377009 Postpartum cardiomyopathy (disorder)