AV Blocks

conduction abnormnalities part 2

1. Conduction abnormalities part II Sruthi Meenaxshi

2. AV Block Atrioventricular (AV) block is defined as a delay or interruption in the transmission of an impulse from the atria to the ventricles due to an anatomical or functional impairment in the conduction system

3. Types First degree AV block  – Delayed conduction from the atrium to the ventricle (defined as a prolonged PR interval of >200 milliseconds) without interruption in atrial to ventricular conduction. ● Second-degree AV block  – Intermittent atrial conduction to the ventricle, often in a regular pattern ( eg , 2:1, 3:2, or other pattern), which are further classified into Mobitz type I ( Wenckebach ) and Mobitz type II second degree AV block. ● Third-degree (complete AV) block  – No atrial impulses conduct to the ventricle. ● High-grade AV block  – Intermittent atrial conduction to the ventricle with two or more consecutive blocked P waves but without complete AV block.

4. Etiology of AV Block

5. Class I indication for Pacing Complete (third degree) AV block with or without symptoms Advanced second degree AV block (block of two or more consecutive P waves ) Symptomatic second degree AV block, Mobitz type II Symptomatic second degree AV block, Mobitz type I ( Wenckebach ) Second degree AV block, Mobitz type II with a widened QRS or chronic bifascicular block, with or without symptoms Exercise-induced second or third degree AV block (in the absence of myocardial ischemia)

6. A 12 year old boy admitted with painful joints migratory and fever with Ecg showing the Following adnormality ?What is your probable diagnosis?

7. First degree Av Block- Prolonged PR interval >200

8. AV Block: 2nd degree, Mobitz I ( Wenckebach Phenomenon) Progressive prolongation of the PR interval culminating in a non-conducted P wave T he PR interval is longest immediately before the dropped beat The PR interval is shortest immediately after the dropped beat

9. Second degree AV block ( Wenkebach Phenomenon) with 5:4 conduction block

10. Note P wave Progressive prolongation of PR Interval Comment on conduction ratio P:QRS Wenkebach phenomenon

11. A 55 year old male presented to ED with chest pain and palpitation. Cardiac biomarkers were elevated . Ecg showed the following abnormality .what is probable diagnosis and localize the territory of MI

12. A case of inferior wall MI , with RV infarction Note the progressive prolongation of PR interval with dropped beat Conduction ratio is 2 :1 (showing wenkebach phenomenon) Since ST Elevation lead III>lead II ( RCA territory infarct )

13. AV Block:  2nd degree AV block , Mobitz II (Hay Block) Intermittent non-conducted P waves  without  progressive prolongation of the PR interval  Mobitz typeII predominantly infrahisian associated with wide QRS and bifascicular and trifascicular blocks Atropine hence contraindicated as it may progress to 3 rd degree AV Block

14. Fixed block mobitz type 2 (4:1)

15. A 54year old with progressive muscle dystrophy presented with this Ecg abnormality.identify

16. A case of limb girdle muscular dystrophy with mobitz type 2 block Class I indication for PPI

17. Complete heart block (Third degree)

18. Complete heart block AV dissociation

19. Complete heart block with inferior wall MI

20. CHB with isorhythmic AVdissociation

21. Thankyou