The difference between Wenckebach and CHB is that:
◦ CHB has an irregular P-P interval, whereas it's regular in Wenckebach.
◦ CHB has more P waves than QRS complexes, whereas Wenckebach always has one P wave for every QRS complex.
◦ CHB has a regular R-R, whereas Wenckebach is irregular.
◦ CHB has a constant PRI, whereas in Wenckebach it gets progressively longer.