Medical Care: One must remember that a healthy fetus depends on a healthy mother. Patients with systolic dysfunction during pregnancy are treated the same as patients who are not pregnant. Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) should be avoided. The mainstays of medical therapy are digoxin, loop diuretics, and afterload reduction with hydralazine and nitrates. Due to a high risk for venous and arterial thrombosis, anticoagulation with heparin should be instituted.
Careful clinical assessment can render invasive hemodynamic monitoring unnecessary. Nitrates and inotropic support with dobutamine should be used when clinically indicated.
Vaginal deliveries are preferred because third-spacing of fluid, endometritis, and pulmonary emboli occur much more often after cesarean deliveries.
Early and effective pain control during delivery is paramount. Regional anesthesia, such as epidural or spinal, is not associated with the myocardial depression observed with inhaled anesthetics.
" Digoxin, diuretics, and afterload reduction
o Use inotropic support with dobutamine when indicated. Improving cardiac output ensures adequate uteroplacental perfusion.
o Use diuretics when the mother is volume overloaded, but be careful because maternal volume depletion can lead to uteroplacental hypoperfusion.
o Hydralazine, in combination with nitrates, is the first choice for afterload reduction and vasodilatation during pregnancy.
o Nitrates may be used to decrease maternal preload, when indicated, and are safe to the mother and fetus. As with any medication that alters maternal hemodynamics, a drop in blood pressure can result in fetal hypoperfusion and distress. Intravenous drips should be titrated very slowly, and maternal intravascular euvolemia should be maintained.
" Anticoagulation
o Arterial or venous thrombosis has been reported in as many as 50% of women with PPCM, and the risk likely is related to the degree of chamber enlargement, systolic dysfunction, and the presence of atrial fibrillation. Pregnancy is a hypercoagulable state. Once the diagnosis of PPCM is established, anticoagulation should be considered and continued until at least 6 weeks postpartum.
o Heparin is the drug of choice. Unfractionated heparin (UFH) has an advantage over low molecular weight heparin (LMWH) because of the ease with which the level of anticoagulation with UFH can be assessed by obtaining an activated partial thromboplastin time (aPTT). In addition, protamine is not as effective at reversing LMWH in the setting of obstetric bleeding. The decision to use prophylactic dosing versus a high-dose regimen that will elevate the aPTT must be individualized based on obstetric issues and the severity of the disease. Women with atrial fibrillation, documented left ventricular thrombus, an ejection fraction <30%, or severely dilated ventricles should receive full-dose subcutaneous heparin to prevent arterial embolism. Refer to Medications for specific dosing recommendations.
o Warfarin carries a risk of spontaneous fetal cerebral hemorrhage in the second and third trimesters but is compatible with breastfeeding and is, therefore, the preferred medication postpartum.
o Due to the occurrence of epidural hematomas, the American Society of Anesthesiology recommends that women on full-dose LMWH not receive spinal or epidural anesthesia for 24 hours after the last injection. Therefore, if cesarean delivery is required, these patients may receive an inhaled anesthetic that can further depress myocardial contractility.
" Antiplatelet agents
o A recent open-label clinical trial assigned a group of women with PPCM to pentoxifylline 400 mg tid. All patients were treated with diuretics, digoxin, enalapril, and carvedilol.
o A combined end-point of poor outcome, defined as death, failure to improve the left ventricular ejection fraction more than 10 absolute points or functional class III or IV at latest follow-up, occurred in 27% of patients treated with pentoxifylline and in 52% of those on usual therapy (P = .03).
" Small, published, randomized trials of pentoxifylline have shown that it may improve symptoms, left ventricular function, and lower levels of inflammatory cytokines such as TNF-alpha. However, not all studies found a beneficial effect.
" Pain control
o Maternal pain control is paramount. The uterus can expel the fetus without maternal pushing.
o Ideally, the laboring patient will receive early epidural anesthesia, and labor will be augmented with oxytocin, when necessary.
o The patient should not be allowed to push, and the obstetrician may apply a low-forceps or a vacuum device to assist with the final stage of the delivery.
" Route of delivery
o Unless the mother is decompensating, managing her medically and waiting for a spontaneous vaginal delivery is reasonable.
o If she is not responding to medical therapy or if the fetus must be delivered for obstetric reasons, the best plan is to induce labor with the goal of a vaginal delivery.
o Vaginal deliveries are associated with much lower rates of complications, such as endometritis and pulmonary embolism, 75% of which occur in association with cesarean delivery.
o Vaginal deliveries are not associated with the postoperative third-spacing of fluid that occurs after cesarean deliveries. This third-spaced fluid reverses after approximately 48 hours, leading to intravascular volume overload and possible maternal decompensation.
o Delivering the fetus decreases the metabolic demands on the mother, but afterload increases due to the loss of the low-resistance placental bed.
" Immunosuppression should not be used empirically, and current evidence does not support the routine use of immunosuppressive agents for myocarditis.
Surgical Care:
" Use intra-aortic balloon pumps when indicated.
" Cardiac transplantation and left ventricular assist devices have been used to treat PPCM. These should be considered for women with progressive left ventricular dysfunction or deterioration despite medical therapy. Most centers will need to consider transfer of such patients to a heart-transplant center for such therapy. However, left ventricular function in most of these patients improves over time, and surgical therapy should be delayed if possible.
Diet: Low sodium (2 g/d sodium chloride)
Activity:
" Strict bedrest may increase the risk of venous thromboembolism and no longer is recommended as a mainstay of therapy.
" Activity should be limited only by the patient's symptoms. In severe cases of true PPCM, bedrest may promote better uteroplacental perfusion.
DRUG TREATMENT :
1. VASODILATORS :
- HYDRALAZINE
2. CARDIO-SELECTIVE BETA BLOCKERS
- LABETALOL
- ATENOLOL
- METOPROLOL
- CARVEDILOL
3. CALCIUM CHANNEL BLOCKERS :
- AMLODIPINE
4. IONOTROPIC AGENTS :
- DIGOXIN
- DOBUTAMINE
5. LOOP DIURETICS :
- FRUSEMIDE
- BUMETANIDE
6. POTASSIUM SPARING DIURETICS :
- SPIRONOLACTONE
7. NITRATES :
- ISOSORBIDE DINITRATE
- NITROGLYCERINE
8. ANTICOAGULANTS : SHOULD BE GIVEN TILL 6 WEEKS POSTPARTUM.
- HEPARIN OR LOW MOLECULAR WEIGHT HEPARIN DURING PREGNANCY
- WARFARIN MAY BE GIVEN AFTER DELIVERY, AS IT IS SAFE FOR INFANTS ON BREAST FEED
9. ANTIARRHYTHMICS :
- LIDOCAINE
- PROCAINAMIDE
- ADENOSINE
10. ANTIPLATELET AGENTS :
- PENTOXIFYLLINE
11. INTRAVENOUS IMMUNE GLOBULIN MAY HAVE A ROLE ALTHOUGH IT DOES NOT APPEAR TO BE BENEFICIAL IN IDIOPATHIC DILATED CARDIOMYOPATHY