6. 1 st Degree AV Block Causes: Increased vagal tone Hyperkalemia Amiodarone, BB’s, CCB’s, or Digitalis Acute Rheumatic Fever Myocarditis Temporary after an inferior wall MI Degenrative changes associated with aging Idiopathic

7. 1 st Degree AV Block Rhythm: Regular or Irregular (depends on underlying) Rate: 60 – 100 bpm (depends on underlying); can be faster or slower P waves: Upright & uniform PRI: > 0.20 sec (constant) QRS: usually narrow ( < 0.12 sec)

8. 1 st Degree AVB

11. 2 nd Degree AVB Type I

14. Complete AV Block Complete “communication breach” between the SA node and ventricular conduction known as AV dissociation The block may occur from within the AV junction or at the bundle branches, a lower area of the conduction system This will determine the ventricular rate and the morphology of the QRS complex

15. 3 rd Degree AVB

16. Complete AV Block If the block occurs at the AV junction, the firing rate will usually be 40-60 bpm with a narrow QRS complex If the block is in the bundle branches, then the rate will usually be 20-40 bpm with a wide QRS complex

17. Complete AV Block Ventricular rate is independent of the atrial rate (60-100) Some P waves may be hidden within the QRS or T wave PRI will vary greatly with no apparent pattern (unlike Mobitz 1 and Mobitz 2)

18. Complete AV Block Causes Temporary Complete AV Block: Inferior Wall MI, Increased vagal tone, drug effects, hyperkalemia, acute rheumatic fever, or myocarditis Causes Permanent Complete AV Block: Acute Anterior Wall MI Chronic Degenerative Changes related with Aging

20. Complete AV Block Complete AV Blovk with a Junctional Focus: QRS is narrow (rate 40-60)

21. Complete AV Block Complete AV Block with a Ventricular Focus: QRS is wide (rate 20-40)

24. TIME TO WORKOUT!!!