ABSTRACT
Mobitz type II: No progressive prolongation of PR interval. However, abrupt conduction failure occurs
Third-degree Complete heart block with AV dissociation (bottom
ECG). If the QRS complex is narrow, this is likely AV nodal block, whereas a widened QRS likely implies His-Purkinje system block
• According to the AHA and the ACC, implantation of permanent pacemakers in asymptomatic patients is according to the following guidelines:
Class I (universally accepted): Third-degree AV block with documented asystole 3
seconds or more, or escape rate less than 40 beats per minute while awake
Third-degree AV block or second-degree Mobitz type II block with chronic trifascicular or bifascicular block
Class II (potential indications): Third-degree AV block with escape rate more than 40
beats per minute Second-degree AV block with no evidence of trifascic-
ular or bifascicular block Class III (pacing not indicated):
Asymptomatic first-degree and second-degree Mobitz type I AV block
