Second Degree Heart Block Type II ECG Interpretation

ECG Strip

ecg rhythm strip for reference guide

Second Degree Heart Block Type II Rhythm Strip Features

Rate: Characterized by Atrial rate usually faster than ventricular rate (usually slow)
Rhythm: Regular (atrial) and irregular (ventricular)
P Wave: Normal form, but more P waves than QRS complexes
PR Interval: Normal or prolonged
QRS: Normal or wide
A constant P-R interval with missing QRS complexes. Occurring in a specific pattern in a ratio with the P waves.
Second degree Heart Block Mobitz II is characterized by intermittently non-conducted P waves which are not preceded by PR prolongation and are not followed by PR shortening. Mobitz II is usually caused by conduction failure/delay of the His-Purkinje system. In three out of four cases, this conduction block is located distal to the Bundle of His, creating wide QRS complexes. In the other 25% of cases, the block is located within the Bundle of His, producing narrower QRS complexes.
External Source: http://
Texas Heart Institute

Authors and Sources

Authors and Reviewers


An error has occurred. This application may no longer respond until reloaded. Reload 🗙