Which heart condition may be indicated by a prolonged QRS complex?

A prolonged QRS complex is indicative of a delay in the electrical conduction through the ventricles of the heart. This can occur in conditions such as bundle branch block, where one of the branches of the conduction system is impaired. In a normal conduction system, the electrical impulse travels through the bundle branches swiftly, leading to a narrow QRS complex on the ECG. However, if there is a block in one of these branches, the impulse takes longer to spread throughout the ventricles, resulting in a wider QRS complex.

Bundle branch block can be observable in various forms, including right and left bundle branch block. In either case, the prolongation of the QRS complex is one of the key findings used to identify the presence of this condition on an ECG.

While conditions such as atrial fibrillation and heart block can also affect heart rhythms and electrical activity, they typically present with features distinct from a mere prolongation of the QRS complex. For instance, atrial fibrillation is characterized by an irregularly irregular rhythm without a distinct QRS complex prolongation, and heart block generally refers to delays in the atrioventricular node rather than conduction issues within the ventricles themselves. Therefore, the presence of a prolonged QRS complex directs