Cardiology ECG P-R Interval Differential Diagnosis

Prolonged P-R Interval = 1st Degree Heart Block 

Short P-R Interval = WPW Syndrome with presence of Delta Wave

                                              or Lown-Ganong-Levin (LGL) Syndrome here delta wave is absent                                           Nodal Rhythm

High Nodal Ectopic                                

Variable P-R Interval = Mobitz type I heart Block ( Wenckebach Phenomenon) fg