What are the two main characteristics of atrial fibrillation?

Atrial fibrillation is characterized primarily by an irregularly irregular rhythm and the absence of distinct P waves on an electrocardiogram (ECG). The term "irregularly irregular" refers to the unpredictable timing of the heartbeats, which can vary greatly as the atria quiver rather than contracting effectively. This leads to the chaotic electrical activity characteristic of atrial fibrillation, which also results in the lack of distinct P waves, as the atrial contractions are not coordinated enough to produce consistent waves on the ECG.

This combination of features is crucial for recognizing atrial fibrillation, as it distinguishes this arrhythmia from other types that may have a more regular rhythm or clearly visible P waves. Understanding these characteristics is essential for effective diagnosis and subsequent management of the condition.