First-degree AV blockFirst-degree AV block is a delay in impulse conduction from the atria to the ventricles, manifested by prolongation of the PQ (PR) interval on the ECG.
Second-degree AV blockSecond-degree AV block is the intermittent failure of conduction of some atrial impulses to the ventricles: one or more P waves are not followed by a QRS complex.
Second-degree AV block, Mobitz type I (Wenckebach)Second-degree AV block, Mobitz type I (Wenckebach periodicity) is an impairment of impulse conduction through the AV node in which the PQ interval progressively lengthens until the impulse...
2:1 AV block2:1 AV block is a form of second-degree AV block in which only every second atrial impulse is conducted to the ventricles, while the other is blocked in the AV node or below.
High-grade AV blockHigh-grade AV block is a form of second-degree AV block characterized by consecutive blockades of two or more P waves without reaching the ventricles.
Complete AV block (third-degree)Complete heart block (third-degree AV block) is the complete absence of impulse conduction from the atria to the ventricles through the AV node or the His-Purkinje system.
Stokes-Adams attackAdams-Stokes syndrome (Stokes-Adams attack) is a syncopal or presyncopal episode caused by a sudden, sharp drop in cardiac output due to cardiac arrest or critical slowing...
Wenckebach periodicitySamoyloff-Wenckebach periodicity (Wenckebach periodicity) is a characteristic cyclical conduction pattern in which the PQ (PR) interval progressively lengthens from cycle to cycle,...
Frederic's syndromeFrederic's syndrome is classically the combination of atrial fibrillation with complete (third-degree) AV block; some authors also apply it to a similar picture during atrial flutter...
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