Changing PR interval

changing PR interval is different for each beat. Most often it progressively gets longer and longer, then there is a dropped beat before it starts again. This is usually caused by a second degree conduction block (or delay) at the AV node, called Wenckebach. If the PR interval is constantly changing without evidence of progressively lengthening, there may be a complete AV block.

See also: PR interval & segment

Can you add to the information on this page?

This ECG Archive is an academic, non-commercial #FOAMed project aiming to crowdsource a free open access database of ECGs and signs. If you include your personal details such as your name you will be attributed for your contribution, unless you tell us that you don't want this to happen. Personal contact details such as email addresses will not be published but may be used to email you in reply. Full project details and participant information available here.

Featured Example

ECG Library (21)

Sort by:
TitleDate
ASCDESC
Show:
31030
Columns:
In the ECGquest archives, this ECG has been tagged with: - Chest pain 12-Lead Changing PR interval Grouped Inferior ST elevation Normal Axis Reciprocal ST depression Second degree AV block type 1 - Wenckebach Acute Inferior MI ECG Interpretation CC-BY-NC-SA
ECG Blog #154 (STEMI – Inferior – Posterior – LVH – Mobitz – AV Block)