This ECG has both second ... I AV block), however at times P waves are randomly not conducted (2:1 AV block). Note the irregular R-R intervals making 3rd degree heart block unlikely. The rhythm ...

This is called 2:1 AV block, as depicted below: When 2:1 AV block is present, the rhythm may be second-degree type I or second-degree type II AV block. Exercising the patient will increase AV ...

All cases admitted or discharged from our institution between January 2008 and June 2009 with a diagnosis of AV block were reviewed. In addition, beginning in June 2009, data from all patients ...

and sinus rhythm replaces the ectopic atrial rhythm when the heart rate is increased during exercise. In Mobitz type I second-degree AV block, the PR interval progressively lengthens from beat to beat ...