AV Block

[Anonymous]

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Fig 1: Second-degree AV block, type 1 (Mobitz 1, Wenckebach): RR almost always irregular, progressively longer PR intervals with dropped QRS complexes (some P waves do not conduct).

Fig 2: Second-degree AV block, type 2 (Mobitz 2): RR may be regular or irregular. Classical 2:1 block will have regular RR intervals; with variable conduction ratios, RR intervals will vary. Beats that conduct have fixed PR intervals, some P waves do not conduct.

Fig 3: Complete Heart Block: Atrial rhythm and ventricular rhythm usually regular, variable PR intervals random lengths (P waves are unrelated to QRS's) more P's than QRS complexes.

[Anonymous]

Treatment:
Long-term medical therapy is not indicated in AV block. Permanent pacing is the therapy of choice in advanced AV block, and it does not require concomitant medical therapy. Sometimes AV nodal blocking medications that contribute to heart block can be discontinued if not necessary. Temporary transcutaneous or transvenous pacing is the treatment of choice for an emergency involving a slow heart rate (and for asystole) caused by AV blocks. In emergencies where bradycardia is caused by a proximal AV block (located in the AV node), atropine administration may improve AV conduction.