Abstract

Here we report an unusual development of peripartum cardiomyopathy (PPCM) in a parturient woman with preeclampsia. A 36-year-old nulliparous parturient woman underwent elective cesarean section for delivery of twins under spinal anesthesia. Both preoperative workup and past history were unremarkable except for proteinuria and hypertension for 1 week. Approximately 4 hours after cesarean section, progressive orthopnea developed. Chest plain film showed acute pulmonary edema, bilateral pulmonary infiltration with interstitial patches, and cardiomegaly. Postpartum cardiomyopathy was diagnosed afterward by echocardiography. This showed general hypokinesia and severe dysfunction of the left ventricle with ejection fraction of 15-20%. She was admitted to the intensive care unit for further management. Fortunately, the patient recovered after treatment and was discharged 15 days later. This case illustrates that we should bear in mind the possibility of PPCM if orthopnea develops while delivery is approaching in a parturient with preeclampsia. Echocardiography is helpful for early diagnosis of PPCM.

Keywords

cardiomyopathies; preeclampsia; puerperal disorders;

1. Introduction

Many  complicated  obstetric  conditions,  including  amniotic  fluid  embolism,  postpartum  hemorrhage,  preeclampsia    with    peripartum    cardiomyopathy    (PPCM)  and  HELLP  syndrome  (hemolysis,  elevated  liver enzymes and low platelets) have been reported, of which preeclampsia is responsible for up to 8% of complicated pregnancies. In contrast, PPCM is rarely observed and has an unknown etiology. PPCM is char-acterized  by  an  acute  onset  of  heart  failure  within  1 month before delivery or 5 months postpartum.^1,2 

A number of factors are thought to increase the risk of developing PPCM. Here, we report an unusual case of PPCM that developed in combination with preec-lampsia. We also review the risk factors, new treat-ment   options   and   the   outcomes   of   subsequent   pregnancies in women with PPCM.

2. Case Report

A 36-year-old woman, gravida 0, para 0, and bearing twins, presented at our obstetric clinic to investigate irregular labor contraction at 37 4/7 weeks of ges-tation. The patient had an unremarkable medical history. At presentation, she had been experiencing slight shortness of breath for 1 week. Bilateral lower leg  edema  and  hypertension  were  found.  Conse-quently, a cesarean section delivery was suggested under the impression of preeclampsia. Preoperative evaluations, including laboratory studies, were un-remarkable. In addition, her vital signs were rela-tively stable after management in the ordinary ward.

On the day of surgery, she was slightly nervous and her vital signs on arrival at the operating room were as follows: blood pressure was 170/110 mmHg, heart rate was 130 beats/minute and respiratory rate was 20−25 breaths/minute. Spinal anesthesia was performed with 11 mg of bupivacaine. Surprisingly, her tachypnea subsided after spinal anesthesia and the operation and delivery proceeded uneventfully. The  total  intraoperative  fluid  given  was  approxi-mately 800 mL of normal saline. She was sent to the postanesthesia room for close observation, where she received 25 mg of pethidine (25 mg) to control her shivering. She was then returned to the ordinary ward with stable vital signs.

However,  4  hours  after  the  cesarean  section,  she  exhibited  progressive  orthopnea  (respiratory  rate: 25 breaths/minute). A chest X-ray (Figure 1) was taken and revealed bilateral upward pulmonary infiltration with opaque interstitial patches, pleu-ral effusion and cardiomegaly. Electrocardiography (Figure 2) showed normal sinus rhythm, left atrial enlargement and poor R wave progression in leads V1−V4. Moreover, arterial blood gases analysis re-vealed that her PaO₂ was 165 mmHg while breathing oxygen  at  a  flow  rate  of  10  L/minute  via  a  non-rebreathing  mask.  As  her  condition  continued  to  worsen,  she  was  transferred  to  an  intensive  care  unit (ICU) for further management. Echocardiography was  done  immediately  on  arrival  at  the  ICU  and  showed general hypokinesia with severe left ven-tricular  dysfunction  (ejection  fraction:  15−20%). Therefore, PPCM was diagnosed by the cardiologist. Consequently,  fluid  restriction  was  started,  and  diuretics, β-blockers  and  inotropic  agents  were  administered to treat heart failure. Right cardiac catheterization was also performed but revealed no significant findings. As her condition showed improve-ments after 5 days in the ICU, she was returned to a  general  ward  and  was  discharged  15  days  later  with limited ambulation. Six months later, when she came for follow up, her cardiac function status was defined  as  congestive  heart  failure,  New  York  Heart Association Functional Class II, and her daily activity was steadily improving.
 

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Chest X-ray shows cardiomegaly, interstitial infiltration and patch opacities over both lung fields, and bilateral pleural effusion.

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Electrocardiography shows normal sinus rhythm, left anterior fascicular block, left atrial enlargement, and poor R wave progression.

3. Discussion

Here, we report a parturient who developed PPCM 4  hours  after  cesarean  section  delivery  of  twins.  One week before delivery, she was diagnosed with preeclampsia because of hypertension, lower limb edema,  shortness  of  breath  and  irregular  uterine  contraction. PPCM is a rare parturient disorder of unknown cause that is characterized by acute onset of heart failure within 1 month before delivery to 5 months postpartum.^1,2 PPCM is defined based on four  criteria:  (1)  development  of  cardiac  failure  in the last month of pregnancy or within 5 months postpartum; (2) the absence of an identifiable cause for the cardiac failure; (3) absence of recognizable heart disease before the last month of pregnancy; and (4) left ventricular systolic dysfunction based on classic echocardiographic criteria.3 The incidence of PPCM is currently estimated to be approximately 1 in 3000 to 1 in 4000 live births. However, it must be noted that population-based estimates are not currently  available  and  the  diagnosis  of  this  rare  disease is not always straightforward.⁴

The  diagnosis  of  PPCM  relies  on  the  echo  -cardiographic   identification   of   left   ventricular   systolic  dysfunction,  which  happens  before  the  narrow period of late pregnancy and postpartum. Differentiating  subtle  symptoms  of  heart  failure  (exercise dyspnea, fatigue, and pedal edema) from normal findings in late pregnancy is a challenge for cardiologists. Therefore, it is essential to consider the presence of PPCM if the symptoms are ambigu-ous. In our case, the tachypnea subsided after spinal anesthesia. This might result from the vasodilatory effect  of  spinal  anesthesia,  which  decreased  the  systemic vascular resistance and improved the per-formance of the heart. However, progressive orthop-nea developed 4 hours after cesarean section, which suggests that the improvements in systemic vascu-lar resistance increased the work of the heart again. Thus, it is possible that the spinal anesthesia masked the signs of heart failure and prevented the clinician from diagnosing PPCM. Therefore, we should cau-tiously  manage  parturients  who  develop  dyspnea  during delivery.

The  etiology  and  risk  factors  of  PPCM  are  un-known. A number of articles have proposed various mechanisms and presented conflicting evidence for the pathogenesis of PPCM, including viral myocar-ditis,  abnormal  immune  responses  to  pregnancy,  abnormal responses to the hemodynamic stress of pregnancy, accelerated myocyte apoptosis, cytokine-induced inflammation, malnutrition, genetic factors, excessive prolactin production, abnormal hormonal function, increasing adrenergic tone, and myocardial ischemia.5 Of note, excessive prolactin production has  been  reported  to  play  a  marked  role  in  the pa thogenesis of PPCM in pregnant mice and women.⁶ Accordingly, it has been reported that bromocrip-tine, a dopamine 2 receptor antagonist, which inhib-its prolactin secretion in combination with standard therapy, can improve the symptoms of PPCM. In addi-tion, a number of factors are thought to increase the risk of PPCM.⁷ However, routine screening for PPCM in this high-risk population is very difficult to rec-ommend, unless the risk factors can be confidently identified.  Although  PPCM  is  a  rare  complication  of preeclampsia, anesthesiologists and intensivists should be aware of the likelihood of PPCM in partu-rients with preeclampsia.⁸

In  the  absence  of  systematic  clinical  studies  to  compare  the  therapeutic  approaches  to  treat  PPCM,  the  standard  therapeutic  modalities  for  heart  failure,  including  salt  restriction,  diuretics,  vasodilators   and   digoxin,   should   be   initiated.   However,  the  clinician  should  consider  neonatal  safety because maternal excretion of drugs or their metabolites may be harmful to the neonate through breast feeding after delivery. Angiotensin-converting enzyme inhibitors given during late pregnancy and parturition are contraindicated because they may cause  teratogenicity,  neonatal  anuric  failure  and  neonatal death, but they should be considered as the primary treatment for PPCM after delivery.⁹ β-adrenoceptor  antagonists  have  been  reported  to  improve the overall survival in parturients with di-lated cardiomyopathy.¹⁰ Additionally, atrial arrhyth-mia should  be  treated  with  digoxin,  which  may  exert  positive  inotropic  effects  on  PPCM.  Never-theless,  Class  III  (e.g.  amiodarone)  and  Class  IV  (e.g.  verapamil)  antiar  rhythmic  agents  should  be  avoided because of their severe side effects, which may  include  fetal  hypothyroidism  and  premature  delivery.¹¹

When cardiomyopathy occurs during late preg-nancy, early delivery of the fetus is recommended to reduce hemodynamic stress on the maternal heart. The  mode  of  delivery  for  a  parturient  with  PPCM  is generally based on obstetric indications.¹² After optimizing the mother’s condition by the cardiolo-gist and obstetrician, the induction of vaginal de-livery can be attempted in most cases, with close cooperation  with  the  consulting  anesthesiologist.  The advantages of vaginal delivery are little blood loss, greater hemodynamic stability, low risk of post-operative infection, and low incidence of pulmonary complications. Cesarean section delivery should be reserved for events in which it is indicated, such as fetal distress or failure of parturition to progress. For cesarean section delivery, regional or general an-esthesia may be used, depending on the patient’s concurrent anticoagulation medications. In patients given general anesthesia, the anesthetic manage-ment should maintain a normal or acceptable heart rate to decrease oxygen demand and prevent large fluctuations in blood pressure.¹²

The prognosis for PPCM largely depends on the recovery of left ventricular size and function within 6 months after delivery.¹³ Demakis et al reported that about half of the 27 women in their study with PPCM  had  persistent  left  ventricular  dysfunction  and the mortality rate was 85% in 5 years.¹⁴ Similar results were reported in a more recent study.¹⁵ In another study, it was suggested that patients with PPCM recovering from left ventricular systolic dys-function  should  be  followed-up  for  6−12  months  after establishing diagnosis.¹⁶ It is very important to provide continuous treatment with follow-up for an adequate period of time to avoid further decline in heart function.

Finally, the risks associated with subsequent preg-nancies in women with sustained PPCM should be understood by clinicians and communicated to pa-tients.  It  has  been  reported  that,  among  women  with normal left ventricular function after PPCM, 23% develop cardiac dysfunction and 2% die during subsequent pregancies.¹⁷ Among women with per-sistent left ventricular dysfunction after PPCM, 54% develop cardiac dysfunction and 9% die in subsequent pregnancies. Thus, a woman with a history of PPCM should be aware of the risks involved if she wishes to conceive again.17

In conclusion, our case illustrates that PPCM should be suspected and an echocardiography is essential if orthopnea develops in a parturient with preeclamp-sia in the late stage of pregnancy, in parturition or postpartum.