Cardiac arrest in pregnancy is a rare yet life-threatening emergency that presents unique clinical challenges. With both maternal and fetal lives at risk, understanding what causes cardiac arrest in a pregnant patient is essential for timely diagnosis, effective intervention, and improved outcomes. In this article, we’ll explore the key causes, risk factors, complications, and emergency protocols related to maternal cardiac arrest, drawing from the latest clinical research and obstetric cardiology guidelines.
Also Read: Is a Heart Attack Considered an Accidental Death?
Understanding Cardiac Arrest in Pregnancy
Cardiac arrest refers to the sudden cessation of effective heart activity, leading to a stop in blood circulation and oxygen delivery to vital organs. In pregnancy, this is an especially critical situation due to the dual responsibility of saving the mother and the fetus. The physiological changes in pregnancy — increased blood volume, cardiac output, and heart rate — can mask or intensify symptoms, making diagnosis and intervention more complex.
What Are the Causes of Cardiac Arrest in a Pregnant Patient?
Maternal cardiac arrest can occur due to both obstetric and non-obstetric causes. The underlying conditions range from common pregnancy-related complications to rare heart diseases. Let’s break them down:
Obstetric Causes of Cardiac Arrest
These causes are directly related to pregnancy or childbirth and include:
- Postpartum Hemorrhage (PPH): Excessive bleeding following delivery is one of the leading obstetric causes of maternal cardiac arrest.
- Amniotic Fluid Embolism (AFE): A rare but catastrophic condition where amniotic fluid enters the maternal bloodstream, triggering an allergic-like reaction.
- Eclampsia & Severe Preeclampsia: High blood pressure complications leading to seizures or stroke, which may precipitate cardiac arrest.
- Peripartum Cardiomyopathy: A form of heart failure that occurs late in pregnancy or postpartum, leading to the heart’s inability to pump blood efficiently.
- Anesthesia Complications: Adverse reactions to spinal or general anesthesia, particularly during cesarean delivery, may lead to cardiac arrest.
Non-Obstetric Causes of Cardiac Arrest in Pregnancy
These include underlying medical conditions or emergencies that are not pregnancy-specific but are exacerbated by pregnancy:
- Pulmonary Embolism (PE): A blood clot that travels to the lungs, blocking blood flow and potentially causing sudden cardiac arrest.
- Myocardial Infarction (Heart Attack): Although rare in younger women, increasing maternal age and risk factors like hypertension and diabetes raise this risk.
- Congenital or Acquired Heart Disease: Women with preexisting heart conditions such as cardiomyopathy, valve disorders, or arrhythmias are at elevated risk.
- Sepsis: Severe infection leading to systemic inflammation and cardiovascular collapse.
- Drug Administration Issues: Incorrect dosing or contraindicated medications in the third trimester can lead to arrhythmias or cardiac instability.
- Trauma: Motor vehicle accidents or physical injury can result in hemorrhage or cardiac compromise.
Key Risk Factors for Maternal Cardiac Arrest
Understanding who is at increased risk helps in early identification and prevention:
- Advanced maternal age (over 35)
- Preexisting heart disease (congenital or acquired)
- Hypertension or preeclampsia
- Obesity or diabetes
- Smoking or drug use
- History of deep vein thrombosis or pulmonary embolism
- Multiple gestations (e.g., twins)
- Poor prenatal care or lack of access to emergency obstetric services
Can Fever Cause Cardiac Arrest in Pregnancy?
While fever alone is not a direct cause, infection-related fevers, especially when associated with sepsis, can lead to cardiac complications. For example, maternal sepsis may progress to septic shock, impairing cardiovascular function and increasing the likelihood of cardiac arrest in pregnancy.
Symptoms of Cardiac Arrest in Pregnancy
Recognizing early signs can save lives. Some key symptoms include:
- Sudden collapse or unresponsiveness
- No pulse or breathing
- Seizures or syncope
- Severe chest pain
- Shortness of breath not relieved by rest
- Palpitations or irregular heart rhythms
If you are caring for a pregnant patient in cardiac arrest, it’s crucial to start CPR immediately while preparing for possible perimortem cesarean delivery if resuscitation fails.
Emergency Management: ACLS for Pregnant Patients
Treating a cardiac arrest in pregnancy requires modifications to standard Advanced Cardiac Life Support (ACLS) protocols.
Key Actions Include:
- Manual Left Uterine Displacement (LUD): To relieve aortocaval compression by the gravid uterus, which impedes venous return and reduces cardiac output.
- High-Quality CPR: Same depth and rate, but with special attention to positioning and oxygen delivery.
- Early Defibrillation: Defibrillation protocols remain unchanged in pregnancy.
- Perimortem Cesarean Section (Resuscitative Hysterotomy): If return of spontaneous circulation (ROSC) isn’t achieved within 4 minutes of arrest and the uterus is above the umbilicus (~20 weeks), delivery should begin by 5 minutes to improve both maternal and fetal outcomes.
An interdisciplinary team — including obstetricians, anesthesiologists, and cardiologists — is essential for optimal care in maternal cardiac arrest cases.
Post-Resuscitation Care and Monitoring
Pregnant cardiac arrest survivors require intensive post-resuscitation care, including:
- Monitoring for recurrent arrhythmias
- Continuous fetal monitoring (if fetus is viable)
- Echocardiograms and bloodwork
- Neurological assessments
- Planning for early delivery if maternal stability cannot be maintained
Ongoing care in a cardiac unit with maternal-fetal medicine oversight is recommended for high-risk pregnancies.
FAQs About Cardiac Arrest in Pregnancy
Conclusion
Cardiac arrest in pregnancy is rare but carries significant maternal and fetal risks. By understanding the causes of cardiac arrest in a pregnant patient — from obstetric emergencies like hemorrhage and eclampsia to non-obstetric threats like pulmonary embolism and cardiomyopathy — clinicians can prepare for rapid, effective intervention. Improved maternal outcomes rely on early recognition, risk stratification, adherence to cardiac arrest in pregnancy guidelines, and a team-based approach to emergency care.
Disclaimer: The content on Wellness Derive is for informational purposes only and not a substitute for professional medical advice, diagnosis, or treatment. Always consult a healthcare provider for medical concerns.
