INFORMATION FOR WOMEN WHO HAVE CARDIAC ARRHYTHMIA DURING PREGNANCY OR BREASTFEEDING

What is cardiac arrhythmia during pregnancy?

An arrhythmia, or cardiac arrhythmia, is an abnormality with the rate or the rhythm of the heart, meaning that the heartbeat is too slow, too fast and/or irregular. There are various categories of arrhythmia, each of which is further divided into different subtypes.

A bradyarrhythmia (bradycardia) is an abnormally slow heartbeat, meaning that the heart rate is below 60 beats per minute (bpm). Bradycardia also is called heart block. If the heartbeat is just a little too slow and signals are conducted normally from the heart’s atria to the ventricles, it’s called 1st-degree heart block, and it is not harmful. In 2nd-degree heart block, there is a problem in the conduction of signals from a pacemaker called the atrioventricular (AV) node through a conduction system that normally stimulates the ventricles to contract at an optimal moment subsequent to atrial contraction that maximizes the heart’s efficiency. The delay causes problems in the rhythm between the contraction of the atria and the contraction of the ventricles. In 3rd-degree heart block, also called complete heart block (CHB), there is no conduction of signals at all through the AV node, so there is no coordination at all between the atria and ventricles; the atria beat when they want, and the ventricles beat when they want, and they beat at a slow rate.