| 释义 |
DictionarySeeheart blockEncyclopediaSeeHeart Blocksecond-degree heart block
second-degree heart blockA form of atrioventricular block in which only some atrial impulses are conducted to the ventricles. Two variants exist: Mobitz I (Wenckebach) and Mobitz II. In Mobitz I, the P-R intervals become progressively longer until a QRS complex is dropped. Because of the dropped beats, the QRS complexes appear to be clustered (grouped beating) on the electrocardiogram. In Mobitz II, P-R intervals have a constant length, but QRS complexes are dropped periodically, usually every second, third, or fourth beat. See also: heart block |