- PR interval is increased; ( > 0.2 sec); * 1st Degree AV block: > 0.2 sec & P, QRS, T interval is normal * 2nd Degree: Wenckebach:
- QRS dropped w/ PR lengthening;
- decr RR interval (usual w/ concomitant A. fib)
- may be caused by Verapamil, Digitalis, & Propanolol;
- may arise from increased parasympathic tone; Mobitz II: QRS dropped w/o PR lengthening;
- may have associated wide QRS complex;
- usually associatted with Ant MI
- may progress to complete AV block;
- associated with Rt. or Left B.B.B. and wide QRS complex; * 3rd Degree: "complete"
- the ventricles are paced independently;
- w/ CNS symptoms get Stokes Adams Syndrome;
- Rate may be paced by AV node (40-60) or Ventricles (30-40/min)
- Note: sudden appearance may indicated impending MI;
- may arise from Inferior infarction w/ fair prognosis;
- may arise from Digitalis and Propanolol;
- when arising from anterior infarction, poor prognosis, Asystole
- QRS dropped w/ PR lengthening;
- decr RR interval (usual w/ concomitant A. fib)
- may be caused by Verapamil, Digitalis, & Propanolol;
- may arise from increased parasympathic tone; Mobitz II: QRS dropped w/o PR lengthening;
- may have associated wide QRS complex;
- usually associatted with Ant MI
- may progress to complete AV block;
- associated with Rt. or Left B.B.B. and wide QRS complex; * 3rd Degree: "complete"
- the ventricles are paced independently;
- w/ CNS symptoms get Stokes Adams Syndrome;
- Rate may be paced by AV node (40-60) or Ventricles (30-40/min)
- Note: sudden appearance may indicated impending MI;
- may arise from Inferior infarction w/ fair prognosis;
- may arise from Digitalis and Propanolol;
- when arising from anterior infarction, poor prognosis, Asystole