Fetal dysrhythmias: a primer for the obstetrician/gynecologist

During routine fetal auscultation, it is not uncommon to encounter an abnormal fetal heart rate. The rate may be abnormally slow or fast, or irregular. This article focuses on fetal dysrhythmias, defined as any irregular fetal cardiac rhythm or a regular rhythm with an abnormal rate outside the range of 120 to 160 beats per minute (Am J Obstet Gynecol. 2000;182:813-819). This article also helps the reader to recognize the most common types of fetal arrhythmias, understand the fetal risks associated with many fetal arrhythmias, and identify some of the pharmacological options used to treat fetal arrhythmias.