A second-degree block, also known as Wenckebach block, is a type of heart block where some electrical signals from the atrium to the ventricles are delayed or completely blocked. This results in a gradual increase in the time between heartbeats until one heartbeat is dropped. It is often identified on an electrocardiogram (ECG) by a pattern of progressively lengthening intervals. This condition can occur in healthy individuals or may be associated with underlying heart issues. While many people with second-degree block may not experience symptoms, it can lead to complications in some cases, necessitating medical evaluation and monitoring.