20 间电位 a increased phase 4 slope Slow response 100毫秒 cel s 20 电位-2 B40重矿 b decreased thresold levels
a. increased phase 4 slope b. decreased thresold levels Slow response cells
A. Electrophysiological basis of arrhythmias D (2) Afterdepolarization and triggered activity D early afterdepolarization (EAD): 口 phases2,3; I longer Q-T interval (Torsades de pointes); Ca2+ inward flow increases 0 induced by drugs, plasma K+\ o delayed afterdepolarization ( DAD): phase 4: Ca2+ inward flow leads to transient Nat inward flow 口 induced by digitalis intoxication, plasma Ca2+↑,K+↓
(2) Afterdepolarization and triggered activity early afterdepolarization (EAD)： phases 2, 3; longer Q-T interval (Torsades de Pointes); Ca2+ inward flow increases induced by drugs, plasma K+ delayed afterdepolarization (DAD)： phase 4; Ca2+ inward flow leads to transient Na+ inward flow induced by digitalis intoxication, plasma Ca2+, K+ A. Electrophysiological basis of arrhythmias
A Triggered beat DAD Triggered beat B EAD A early afterdepolarization EAD) B. delayed afterdepolarization ( DAD)
A. early afterdepolarization (EAD) B. delayed afterdepolarization (DAD) Triggered beat Triggered beat
A. Electrophysiological basis of arrhythmias I 4. Abnormal conduction ofimpulse D ()Simple conduction block I slow and small depolarization in phase 0, reduced MDP level in phase 4 D MDPV in ischemia, inflammation, metabolic disorders i I Usually occurred in atrioventricular regions
4. Abnormal conduction of impulse (1) Simple conduction block slow and small depolarization in phase 0, reduced MDP level in phase 4 MDP in ischemia, inflammation, metabolic disorders； Usually occurred in atrioventricular regions A. Electrophysiological basis of arrhythmias
A. Electrophysiological basis of arrhythmias I(2) Reentrant reexcitation (reentry) I Circuits (especially in enlarged ventricles) (Wolff-Parkinson-White syndrome) I Unidirectional(one-way) block (myocardial injury) a Slow conduction D Heterogeneity in ERP
(2) Reentrant reexcitation (reentry) Circuits (especially in enlarged ventricles) ( Wolff-Parkinson-White syndrome) Unidirectional (one-way) block (myocardial injury) Slow conduction Heterogeneity in ERP A. Electrophysiological basis of arrhythmias