Left bundle branch block (LBBB) is a type heart block. It results from a problem with the electrical conduction system that enables the heart to beat. It may cause no symptoms, but an ...

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 ...

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 ...

Mobitz type I, also known as the Wenckebach block, is a subtype of second-degree atrioventricular (AV) block. Mobitz type I is a type of conduction disorder, which happens when the electrical signals ...

Dear Dr. Roach: I recently had an EKG that showed first-degree heart block and “inferior infarct, age undetermined.” What does that mean? What should I do to make sure it doesn’t get worse? I will be ...

A specialist tells how to interpret subtle changes on the ECG, including those caused by two life-threatening syndromes you might otherwise miss. Reading ECGs is like learning to appreciate art—it is ...

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 ...