|Year : 2022 | Volume
| Issue : 4 | Page : 272-274
A known case of myocardial infarction and its outcome in pregnancy
Veena M Vernekar, Mangal Gowri, Vedavathy Naik, Ashok Kumar, A Poojitha, S Raziya, S Sreelatha
Department of Obstetrics and Gynaecology, ESIMC PGIMSR, Bengaluru, Karnataka, India
|Date of Submission||22-Oct-2020|
|Date of Decision||21-Mar-2021|
|Date of Acceptance||29-Mar-2021|
|Date of Web Publication||25-Oct-2022|
Dr. Veena M Vernekar
D/o Manjunath V. Vernekar, #25 Shree Mahalasa Narayani Krupa, 6th Cross, Laxmi Nagar, Gokul Road, Hubballi Dharwad, Bengaluru - 560 030, Karnataka
Source of Support: None, Conflict of Interest: None
Acute myocardial infarction (AMI) is rare in women of child- bearing age during pregnancy. Its prevalence is 1/10,000–30,000. A 32-year-old primigravida, with a history of acute MI 1 year ago, presented to us with regular antenatal checkups and was followed up to term. She was asymptomatic throughout her pregnancy. Electrocardiogram, two-dimensional echocardiogram, cardiology opinion, and preanesthetic evaluation were done. Under strict maternal and fetal monitoring, the mother went into spontaneous labor and delivered by vacuum-assisted vaginal delivery. Both the mother and the baby were stable and healthy. She was asymptomatic in her postpartum period and was discharged on postnatal day 8.
Keywords: Echocardiogram, myocardial infarction, pregnancy, primigravida, vacuum-assisted vaginal delivery
|How to cite this article:|
Vernekar VM, Gowri M, Naik V, Kumar A, Poojitha A, Raziya S, Sreelatha S. A known case of myocardial infarction and its outcome in pregnancy. APIK J Int Med 2022;10:272-4
|How to cite this URL:|
Vernekar VM, Gowri M, Naik V, Kumar A, Poojitha A, Raziya S, Sreelatha S. A known case of myocardial infarction and its outcome in pregnancy. APIK J Int Med [serial online] 2022 [cited 2022 Dec 4];10:272-4. Available from: https://www.ajim.in/text.asp?2022/10/4/272/359447
| Introduction|| |
Acute myocardial infarction (AMI) during pregnancy is rare; the estimated incidence is approximately one in 16,000 deliveries. However, it is associated with high maternal and fetal mortality and morbidity. Pregnancy is a hyper coagulable state, and also due to hemodynamic changes in pregnancy like increase in cardiac output, stroke volume etc which increases stress on cardiovascular system, accentuates the risk of AMI by threefold to fourfold. Enhanced stroke volume and heart rate during pregnancy increase the myocardial oxygen demand; furthermore, physiological anemia and decreased diastolic blood pressure also contribute to the development of myocardial ischemia.
Increasing Age especially > 35 years is a risk factor for AMI, AMI can occur during any stage of pregnancy and postpartum, but majority of the cases occur in the third trimester.
Most patients do not have the traditional risk factors for coronary artery disease (CAD). However, cigarette smoking (25%), hyperlipidemia (20%), hypertension (15%), diabetes (9%), and family history of CAD (9%) are the most common risk factors. In addition, preeclampsia, thrombophilia, previous transfusion, postpartum infection, vasculitis, and anemia were found to be significant risk factors for AMI.
| Case Report|| |
We present the case of a 32-year-old unbooked primigravida with 8 months of amenorrhea, with a history of AMI 1 year back, and was on treatment, asymptomatic throughout the pregnancy. She had no specific history of coronary risk factors. Electrocardiogram (ECG), two-dimensional echocardiogram (2D-ECHO), cardiologist opinion, and preanesthetic evaluation were done '[Figure 1]'- Electrocardiographic findings of old anterior wall MI-loss of anterior forces, Q waves in V1 and V2 and poor R progression was seen. Two dimensional Echocardiography findings- mild MR, mild TR, left ventricular (LV) segmental hypokinesia, mildly reduced biventricular systolic function LV ejection fraction (EF) = 45%. Then, she presented to us with labor pain to our labor room, with no complains of breathlessness and chest pain. On examination, general condition - fair, afebrile, pulse rate - 118 bpm, blood pressure - 110/80 mmHg, Cardiovascular System (CVS) - S1S2 heard, and Respiratory System (RS) -Normal Vesicular Breath Sounds (NVBS) heard. On per abdomen examination - Uterus was term size, 3 contractions of 25 seconds each in 1 minutes. On Vaginal examination- the cervix was soft midposition, 2–3 cm dilated 70% effaced, vertex at_2 station, with a Bishop's score of 8. Then, under strict vitals and cardiac and fetal monitoring, she went into active labor and delivered by vacuum-assisted vaginal delivery with episiotomy an alive female baby of 3.25 kg. With consent, PostPartum Intra Uterine Contraceptive Device (PPIUCD) was inserted for effective contraception. Both the mother and the fetus were stable postnatally. She was treated with a 7-day antibiotic course of injection gentamicin 80 mg IV BD, injection augmentin 1.2 g IV BD, and injection metronidazole 100 ml IV TID. Her postnatal TropT was negative; though Creatinine Phosphokinase (CPK) and Creatinine Phosphokinase Myocardial Band (CPKMB) were slightly raised, she was discharged on postnatal day 7 with cardiologist opinion advised to continue on tablet (Tab) ecospirin 75 mg OD, Tab atorva 10 mg OD, Tab Met XL 25 μg OD and asked to review in the cardiology outpatient department after 1 month. The patient was followed up after 1 month. She is asymptomatic and continued on the same treatment.
| Discussion|| |
The incidence of IHD in pregnant women is low, and AMI is uncommon, but it is associated with poor maternal and fetal outcomes. Pregnancy itself accentuates the risk of AMI due to hormonal and hemodynamic changes.
The differential diagnosis of chest pain in pregnancy includes acute pulmonary embolism, aortic dissection, and myocarditis.
The anterior wall is most commonly involved in 70% of cases, inferior wall in 27% of cases, and lateral wall in 4% of cases.
LVEF in most cases was <40% (54%), <30% (24%), and <9% (20%). Acute Myocardial Infarction is associated with catastrophic complications such as heart failure, cardiogenic shock, ventricular arrhythmia, and recurrent angina.
Coronary dissection is a rare cause of AMI in nonpregnant population, which was found to be the most common mechanism of AMI in pregnancy (45%), followed by coronary atherosclerosis (35%), isolated thrombus (17%), and idiopathic (11%).
Coronary dissection mostly involved the left anterior descending (LAD) artery and left main artery (26%), right coronary artery (RCA, 14%), and left circumflex (3%). It is due to hormonal and hematological changes in pregnancy. Excess levels of progesterone lead to a loss of normal corrugation of elastic fibers and a decrease in acid mucopolysaccharide ground substance and also Estrogen increases the release of matrix metalloproteinase which can lead to cystic medial necrosis and lack of structural support for the vasa vasorum and rupture leading to Intra mural hematoma.
The left coronary system is most commonly involved; it is because there is a significant fall in blood flow during systole in the left side, which leads to significant rise in both oscillatory shear stress and wall stress, but RCA has a more uniform blood flow during systole and diastole.
Furthermore, due to more branching in the left side, the LAD artery is subjected to increased torsional force during cardiac cycle compared to RCA.
Atherosclerotic CAD is found to be more common during antepartum period, while coronary dissection is more common in the late third trimester and peripartum and postpartum period, due to hemodynamic changes, especially during labor and delivery.
25% were hemodynamically stable at the time of presentation, 14% needed advanced cardiac life support, and 26% required emergency intra-aortic balloon pump support.
Criteria for the treatment of AMI in pregnant women are in general the same as in nonpregnant patients; however, the diagnostic approach is influenced by the fetal safety. Noninvasive test that poses the least risk to the fetus should be employed first like the electrocardiography and two dimensional echocardiogram. The ECG findings may be – left- or right-axis deviation, small Q waves in lead III, T wave inversion, and ST segment depression. ECHO is useful in evaluating motion wall abnormalities. Measurement of troponin levels is preferred over other cardiac markers as troponin level remains below the upper limit of normal, except in preeclampsia and gestational hypertension where it is mildly elevated, whereas the levels of creatine kinase and CPKMB are increased by nearly twofold within 30 min after delivery due to uterine contraction or cell breakdown that occurs during labor and delivery.
The amount of fetal exposure to radiation should be minimized. Cardiac catheterization, radionuclide imaging, and interventional procedures expose the fetus to radiation of <1 rad. Nuclear stress test is contraindicated.
The treatment of pregnancy women with AMI does not differ from the standard of care of acute coronary syndrome. However, both maternal and fetal condition should be considered for selection of choice of therapy.
A multidisciplinary approach involving the obstetricians, neonatologist, cardiologist, and anesthetist is required. An intensive care unit for providing maternal and fetal monitoring with comprehensive obstetric care should be established.
Standard therapy with morphine, ACE inhibitors, beta-blockers, nitroglycerine, heparin, calcium channel blockers, antiplatelet drugs, statins, and fibrinolytic drugs can be used. However, there is only limited information about fetal safety for the drugs. In a study, 45% of patients who underwent angiography were treated with percutaneous coronary intervention (PCI), but PCI exposes fetus to 3 mGy of radiation. It has a success rate of 65%–70%. Coronary artery bypass grafting is reserved in patients with multiverses involvement and failed PCI.
Mode of delivery in a patient with MI should be determined by obstetric considerations and clinical status of the mother. However, delivery should be delayed for at least 2 weeks from the time of infarction as mortality is higher during this time.
The mortality rate following a vaginal delivery is 14%, while for cesarean section is 23% after MI.
The advantage of vaginal delivery is less blood loss, less infection risk eliminating the potential risk associated with anesthesia, thromboembolism, etc., which are more common following cesarean delivery. Assistance during the second stage of delivery is recommended, The expulsive period should be shortened through instrumentation. Induction with misoprostol or dinoprostone must be avoided as it increases the risk of coronary spasm. Cesarean section must be performed if maternal or fetal decompensation occurs or nonprogression labor or in severe cardiac cases such as aortic stenosis, pulmonary hypertension, and aortic dissection.
During labor, the patient must be positioned in the left lateral position to decrease the aortocaval compression and to maximize cardiac output. Oxygen supplementation should be provided. ECG, pulse oximeter, and fetal heart rate should be monitored continuously. Early epidural anesthesia to minimize pain can be used. Fear and apprehension should be prevented as it increases myocardial oxygen demand.
| Conclusion|| |
Previous MI is not an absolute contraindication to pregnancy. However, it is advisable for patent with previous revascularization or infarction to delay pregnancy for generally at least 1 year after the event to reduce the risk of recurrent ischemia and restenosis. A full cardiac evaluation should be done preconceptionally.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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