Human Anatomy at Colby

Grand Rounds: Postpartum Coronary Artery Dissection

January 28, 2015 · No Comments

Lauren Shirley, Allison O’Connor, Cal Robbins

Grand Rounds Synopsis

Case 28-2010 A 32-Year-Old, 3 Weeks Postpartum with Substernal Chest Pain

Grand Rounds Case Presentation powerpoint pdf

Onset

A 32-year old woman had an uncomplicated, spontaneous vaginal delivery after 39 weeks of gestation. This was the patient’s second pregnancy. During her first pregnancy, she was diagnosed with preeclamptic toxemia which was treated with magnesium sulfate. Mild hypertension (systolic 120-140 mm Hg) was reported during the first and third trimesters of her second pregnancy followed by a return to normal blood pressure. Upon delivery, it was noted that her placenta weighed 340 g (below the fifth percentile for gestational age, mean 540 g) with increased amounts of perivillous fibrin (suggesting placental ischemia- lack of blood and thus oxygen and glucose to tissue).

The patient was admitted three weeks post partum when she developed pain in the left jaw and substernal area. The patient called EMS and was given oxygen which resolved her symptoms after 20 minutes and EMS personnel left. The pain returned shortly and EMS returned whereupon the pt scored her pain as a 7 out of 10. Blood pressure was noted as 148/74 and an electrocardiogram (ECG) revealed normal sinus rhythm of 90-100 bpm and ST-segment elevation of 4 mm in leads V2 and V3 (Abnormalities in ECG). Oxygen, acetyl-salicylic acid, nitroglycerin and morphine were administered. When examined at the hospital, the pt’s blood pressure was 143/92 mm Hg in her left arm and 137/81 mm Hg in her right arm with a pulse of 83-92 bpm.

Diagnosis

With a chief complaint of chest pain the patient could have been experiencing cardiovascular, pulmonary, gastrointestinal or musculoskeletal complications. Since the patient was 32 years old, cardiovascular complications would seem unlikely, however, since the patient was three weeks postpartum cardiovascular complications need to be considered more carefully since the risk of acute myocardial infarction is increased during pregnancy and the postpartum period and since pregnancy is a risk factor for aortic dissection. The risk of pulmonary embolism (a blockage of an artery in the lungs) is also increased during the postpartum period.

Since the patient’s ECG showed ST-segment elevation in conjunction with chest pain, an acute myocardial infarction would be suspected. Approximately 35% of postpartum women who present with myocardial infarction have a coronary artery dissection. There are two main types of coronary artery dissections, those that are caused by mechanical precipitation and those that are spontaneous. A spontaneous dissection is a tear in the artery where the tunica media and tunica externa separate, allowing blood to pool in between these layers. SCAD are rare, however 75% of patients who present with spontaneous aortic dissections are women and 30%  of those women are peripartum, suggesting that this patient’s coronary artery dissection was spontaneous. There are four subgroups of spontaneous coronary artery dissections, however peripartum status and idiopathic spontaneous coronary-artery dissections or those caused by coronary shear stress are the two subgroups relevant to this case. Since the chest pain began after the patient picked up her toddler, there is a high index of suspicion that this dissection may have been caused by the patient’s peripartum status and coronary shear stress caused by lifting her toddler. Angiographic projections showed 35mm long segment of narrowing in the left anterior descending coronary artery.  The lack of vascular disease in other coronary arteries along with the patient’s postpartum status as well as her test results are consistent with the diagnosis of a postpartum coronary-artery dissection.

Treatment Options

Unlike aortic dissections, the usual chest pain drugs (asprin, nitroglycerin, etc) which thin the blood can actually help, keeping the true lamen patent. Beta-blockers and nitrates are often used to prevent superimposed vapospasm.  In cases of myocardial ischemia or compromised coronary flow, reperfusion therapy is used.  In patients with severe ischemia, coronary-artery bypass  grafting is done. In this case, the patient was given an intra aortic balloon pump which helps to increase myocardial oxygen supply by being placed in the aorta where it inflates and decreases based on the heart beat.  Since the patient had no pain and the Percutaneous Coronary Intervention could have entered the false lumen, and since coronary dissections can heal by themselves, the balloon pump makes the most sense.  This increased blood flow to the coronary artery.  Aspirin as an antiplatelet, ß-blockers, and statins were used in case of intramural hematoma in the coronary vessel.  Because of the potential for emergency cardiac surgery, the patient was not given glycoprotein IIb/IIIa inhibitors.

 

After 2 days a significant improvement was noted, the pump was terminated, and since surgery was now unlikely, glycoprotein inhibitors were initiated  for a minor myocardial infarction discovered during treatment of the aortic dissection. This would be discontinued in a year, while aspirin was recommended indefinitely. The patient was able to return to her normal life with no further complications.

 

Little evidence exist in terms of the cause of spontaneous coronary artery dissections, but the current theory is that  inflammation is caused by hormones, which explains the prevalence in post partum women.  Several studies also included women taking oral contraceptives as being at risk for coronary artery dissections.  The eosinophils release the histolytic agents between the tunica media and the tunica adventitia, which cause dissections in coronary arteries.

 

References

  1. Sabatine, Marc S., Farouc A. Jaffer, Paul N. Statts, and James R. Stone. “Case 28-2010: A 32-Year-Old Woman, 3 Weeks Post Partum, with Substernal Chest Pain.”The New England Journal of Medicine (2010): n. pag. Web.
  2. James, A. H. “Acute Myocardial Infarction in Pregnancy: A United States Population-Based Study.” Circulation 113.12 (2006): 1564-571. Web.
  3. Koul, Ashok K., Gerald Hollander, Norbert Moskovits, Robert Frankel, Leo Herrera, and Jacob Shani. “Coronary Artery Dissection during Pregnancy and the Postpartum Period: Two Case Reports and Review of Literature.” Catheterization and Cardiovascular Interventions 52.1 (2001): 88-94. Web.
  4. Mcintyre-Spatar, Leslie, and Kevin H. Silver. “Spontaneous Coronary Artery Dissection in a Postpartum Woman: Literature Review.” The Journal for Nurse Practitioners 7.9 (2011): 770-73.
  5. Oliveira Marta Silvia, Goncalves Alexandra, Dias Paula, Maciel Júlia Maria. “Spontaneous Coronary Artery Dissection: a Diagnosis to consider in Acute Coronary Artery Syndromes” Artigos de Revisão. (2009): 28 (6): 707-713
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  7. CBC. MedlinePlus, 2015. (Accessed Janury 25, 2015 at http://www.nlm.nih.gov/medlineplus/ency/article/003642.htm)
  8. Placental Pathology. University of Chicago. (Accessed January 20, 2015 at https://pathology.uchicago.edu/sites/pathology.uchicago.edu/files/uploads/PDFs/Placental%20Pathology%20Notes%20Aspen%202014%20-Fritsch%20final.pdf)
  9. Electrolytes. AACC, 2013. (Accessed January 25, 2015 at http://labtestsonline.org/understanding/analytes/electrolytes/tab/test/)
  10. CK-MB. AACC, 2013. (Accessed January 25, 2015 at http://labtestsonline.org/understanding/analytes/ckmb/tab/sample/)

 

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