Peri-partum cardiomyopathy, also known as post-partum cardiomyopathy or cardiomyopathy of pregnancy is quite rare, occurring in anywhere from 1 in 1500 to 1 in 4000 gestations.
There are three criteria needed to make the diagnosis:
1) Development of congestive heart failure in the last month of pregnancy or the first five months following delivery. Symptoms of congestive heart failure include: severe swelling of the ex-tremities, especially the legs and ankles; severe shortness of breath. Both of these findings
Occur due to the fact that the heart pumps blood very ineffectively. Blood that should circulate freely, backs up and fluid accumulates in the tissues of the body, which account for swelling in the periphery and fluid amassing in the lungs.
2) No apparent etiology for the heart failure.
3) Absence of probable heart disease prior to the pregnancy.
The cause is unknown, which is part of what makes it so frightening. Many have speculated that the etiology may be viral, alcohol-induced, a complication of hypertanseion or due to atherosclerosis. However, no scientific evidence has supported any of these hypotheses.
We have found that the disease is most prevalent among African-American women whom have had children previously. It has also been found that about 7% occur following a twin pregnancy.
The diagnosis is made in much the same way conventional congestive heart failure is determined. The same constellation of symptoms and clinical signs, as well as radiologic and EKG changes are noted. The most notable x-ray finding is enlargement of the heart. One common sequelae is that of pulmonary or systemic embolus due to the fact that the blood is stagnant, and this state of decreased motion, makes it likely to form a clot, which can travel and cause occlusion of a major blood vessel resulting in tissue or organ death or worse yet, death to the patient.
Treatment involves mandatory complete and prolonged bedrest, which should not end until at least 3 months AFTER the heart has returned to a normal size. If heart enlargement continues, 6-12 months of strict bedrest may become necessary. However, medical therapy includes digitalis, which helps to increase the contractility and work of the heart. Diuretics are also used to minimize swelling and shortness of breath and anti-coagulants are administered to prevent clot formation.
Outcome and prognosis depend upon whether or not the heart returns to its normal size. It appears that when the heart returns to its normal size within 6 months, there was no risk of death from heart disease within the next 11 years; this course is predicted for 50% of those afflicted. For the remaining half, whom have persistent cardiac enlargement after 6 months of bedrest, 85% of these will die of heart failure within 5 years, unless transplant is undertaken.
Peri-partum cardiomyopathy tends to recur in subsequent pregnancies, especially if the woman's heart has remained enlarged. The recommendation for any affected woman is that she undergo sterilization. Oral contraceptive pills, especially anything containing estrogen, are contra-indicated as they increase the risk for clot or embolus formation.
Due to the stress on the heart during labor, there must be certain precautions taken to minimize the work of the heart. First, it imperative that pain is well-controlled during labor, as this can decrease the work of the heart by 20%. Therefore, epidural is the most prescribed method for this entity. Pushing is to be avoided, as it generates higher pressures in the chest cavity and heart. Therefore, uterine contractions are allowed to bring the head almost to delivery and then a low forceps or vacuum delivery should be performed.
Ironically, cesarean section should not be used unless a routine obstetric indication exists like fetal distress. The stress of surgery and the larger blood loss may overwhelm an already weak and stressed heart.
Symptoms for which pregnant women should be aware are:
-shortness of breath
-swollen extremities, especially the lower extremities.
However, it is important to realize that ALL of these symptoms are extremely common in pregnancy, and can be due to the NORMAL physiologic changes which are occurring or due to more common and more innocuous diseases.
For instance, shortness of breath is very common, especially during the late third trimester, as the gravid uterus pushes up on the diaphragm, which in turn, compresses the lungs and decreases lung capacity. This is a normal and necessary change which may cause shortness of birth. However, it can also signal problems like anemia or too much amniotic fluid. Of course, it is quite common in twin pregnancies, as they occupy far more space.
Fatigue is another very common symptom of pregnancy, due to the fact that the body is constantly passing glucose along to the fetus. It is also using any available energy to devote to the growth of the gestation. This means that there is less energy available for everything else, and the result is often severe and intractable fatigue. Anemia, which is also very common in pregnancy due to the massive fetal requirement for hemoglobin, the protein found on red blood cells, is one of the most common causes of fatigue.
Dizziness and/or lightheadedness are also frequent pregnancy-related complaints as glucose is passed along so readily to the fetus at the mother's expense. The result is often hypo-glycemia, which can cause severe dizziness. This is also another symptom often associated with anemia.
Finally, lower extremity swelling is exceedingly common in the last month of pregnancy, as the excess fluid that has been retained in order to maintain the pregnancy shifts in a gravity dependent manner to the legs, ankles and feet. Further, the weight of the almost term uterus obstructs some blood and fluid return to the heart from the legs, and is therefore, also responsible for the lower extremity swelling. Certainly if swelling is due to the dynamics of pregnancy, then it will be most apparent at the end of the day after the woman has been on her feet for several hours, and will usually resolve after a night's rest, when the fluid has the opportunity to redistribute due to the woman's reclining position. If swelling is either against gravity, like in the arms, hands or face OR if it fails to resolve after a night's rest with elevation of the feet, then something pathologic may be occurring. However, the odds of cardiomyopathy are small. The agent is more likely to be pre-eclampsia or toxemia, in which the blood pressure rises, non-dependent swelling occurs and protein is often found in the urine.