NCC Certified Electronic Fetal Monitoring (C-EFM) Practice Exam

What is the most common arrhythmia found in fetuses?

1. Atrial flutter

2. Ventricular tachycardia

3. Premature atrial contractions (PAC)

4. Complete heart block

The correct answer is: Premature atrial contractions (PAC)

The most common arrhythmia found in fetuses is premature atrial contractions (PAC). PACs are characterized by early depolarizations originating in the atria and can occur frequently during fetal development. They are often benign and can be detected during routine electronic fetal monitoring, typically presenting as a premature heartbeat before the expected atrial contraction. The prevalence of PACs in the fetal heart rate patterns is significant, and while they may be concerning in certain contexts, they usually do not indicate serious underlying pathology. Their common occurrence is attributed to the adaptability and resilience of the fetal cardiovascular system. Healthcare providers monitoring fetuses may observe PACs and typically assess their frequency and impact on the overall fetal heart rate to determine if any intervention is required. In contrast, other arrhythmias, such as atrial flutter, ventricular tachycardia, and complete heart block, occur less frequently and are often associated with more severe complications, necessitating closer monitoring and potential intervention. These arrhythmias may indicate underlying health issues requiring further medical evaluation and management. By understanding the common nature of PACs compared to other types of arrhythmias, healthcare professionals can better identify and address any anomalies in fetal heart rhythm.