Second-degree heart block is a type of heart rhythm disorder. There are two types of second degree heart block — Mobitz type 1 and Mobitz type 2. Mobitz type 2 heart block occurs when the electrical ...

Also known as complete heart block, third-degree heart block is the most serious type of heart block. Considered a medical emergency, it can be fatal without prompt treatment. The steady beating of ...

Complete heart block means that there’s a complete separation of electrical activity between the upper and lower chambers of the heart. Without prompt medical attention, it can be fatal. Your heart ...

This ECG shows ventricular pacing. Note the pacer spike prior to each QRS complex, most apparent in leads V5 and V6. The P waves appear sinus in origin and have no association with the QRS complexes ...

This ECG shows P waves that are not always associated with a QRS complex. This is called "AV dissociation" and occurs in complete heart block (a.k.a. 3rd degree heart block). In this situation, the P ...

First-degree heart block is the mildest type and often requires no treatment. Third-degree heart block is the most severe and often needs a pacemaker to regulate the heartbeat. Many different causes ...