Abstract
Arrhythmias are diagnosed using electrocardiograms (ECGs). Particularly for paroxysmal arrhythmias, an ECG recorded during an episode is essential for definitive diagnosis. Meanwhile, biomarkers assessable through blood tests do not directly diagnose arrhythmias, but are considered useful for evaluating the prevalence of paroxysmal arrhythmias, predicting their onset, assessing severity, and evaluating the risk of complications. While most biomarker research in the arrhythmia field focuses on atrial fibrillation, several studies have also reported on the prediction of ventricular arrhythmias and sudden death. This paper defines biomarkers as substances measurable and evaluable through blood tests and primarily discusses their relationship with atrial fibrillation and its complications.