How do structural heart diseases contribute to arrhythmias?

Structural heart diseases play a significant role in the development of arrhythmias primarily by disrupting normal electrical pathways within the heart. When there are changes in the heart's structure—due to factors such as hypertrophy, fibrosis, ischemia, or valve disease—it can lead to alterations in the way electrical signals travel through the heart tissue. These structural changes can create areas of scarring or abnormal tissue that interfere with the conduction of electrical impulses, leading to abnormal rhythms.

For instance, scarring might slow down or block the conduction of impulses, resulting in conditions like atrial fibrillation or ventricular tachycardia. Additionally, the remodeling of heart tissue can change the location or distribution of ion channels, further affecting how the heart's electrical activity is synchronized. This disruption is a key mechanism through which structural heart diseases can create a substrate for arrhythmias to occur, making it essential to understand these interactions when diagnosing and managing patients with arrhythmias.