67 year-old man status post ablation for atrial fibrillation presents with this ECG
- Is the 9th P wave premature?
- What accounts for the PR prolongation?
- No. The 9th P wave is not premature.
- Concealed Conduction accounts for the PR prolongation.
As seen best in rhythm strip V1, all of the P waves on this tracing are equidistant and are sinus beats according to the P wave axis. The VPC that precedes the 9th P wave retrograde conducts across the AV node. While it is not sufficient to block forward conduction of the next sinus beat, it does prolong the ensuing PR interval.
Powered by EKGaction: EKGaction is much more than the usual textbook of EKG and is different from other online programs. It teaches/reinforces EKG interpretation skills using a method that integrates clinical pearls that makes it easier to commit to memory. These pearls accompany every case and are called Learning Points and Collateral Tracings. The multiple indexes make it useful as a reference. It has been perfected over 15 years, teaching at leading cardiology fellowship programs. It has been shown to improve performance on board exams and it’s fun to use!Learn more at https://www.ekgaction.com/