心律失常英文版.ppt

(4)Left posterior fascicular block(LPFB) Right axis deviation＞+120。. rS in I, AVL, qR in III,AVF ,RIII＞RII. QRS duration ＜0.12s. Rare in clinical Preexcitation Syndrome The most frequently encountered type of ventricular preexcitation is that associated with AV bypass Mechanism of Preexcitation 1.WPW Syndrome (Wolff-Parkinson-While syndrome) AV bypass tracts that conduct in an antegrade directial produce a typical ECG pattern of a short PR interval(0.12s),a slurred upstroke of the QRS complex, and a wide QRS complex.This pattern from a fusion of activation of the ventricles over both bypass tract and the AV nodal His-Purkinje system. Features of Preexcitation syndrome ? P-R0.12s ? QRS =0.12s, δwave ? Secondary ST-T change ? STV often seen kent bypass ECG in Wolff-Parkinson-While syndrome. 1.There is a short PR interval(0.12s), 2.a wide QRS complex(≥0.12s), 3. slurring(delta wave) on the upstroke of the QRS produced by early ventricular activation over the bypass tract 4.P-J interval is normal . 5.secondary ST-T wave changes that are generally opposite to the major delta and QRS vectors. Type A preexcitation syndrome Type B preexcitation syndrome 2.LGL syndrome Jamos bapass ECG in LGL syndrome. 1.There is a short PR interval(0.12s), 2.a normal QRS complex(0.11s), 3. has no slurring(delta wave) on the upstroke of the QRS 3.Mahaim syndrome ECG in Mahaim syndrome. 1.There is a normal PR interval 2.a wide QRS complex(≥0.12s), 3. slurring(delta wave) on the upstroke of the QRS Escape beat and escape rhythm The escape rhythm may arise from junctional area, in which case its rate will tipically be 40-60bpm, or it may arise from ventricular area with a rate of 20-40bpm. junctional escape rhythm 1.the most common escape rhythm 2. Mostly due to sinus arrest, Ⅱ。AVB 3.QRS wave is Characterized the performance of junctional beats 4. rate will tipically be 40-60bpm junctional escape ventricular escape rhythm 1. Mostly due to double knot disease, Ⅲ 。AVB 2.QRS wave