Term
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Definition
| depolarizations due to faster firing cause a more negative RMP (hyperpolarization), making the other nodes less likely to spontaneously fire |
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Term
| Early Afterdepolarizations (EADs) |
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Definition
| interrupt phase 2&3 repolarization, arise from prolonged AP plateau, exacerbated at slow HR, associated with Long QT Syndrome |
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Term
| Delayed Afterdepolarizations (DADs) |
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Definition
| occur after full repolarization, arise from RMP, increased stimulation rate may cause amplitude to increase until firing (self-sustained firing), often due to mutant Ryanidine Receptors |
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Term
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Definition
| normal SR Ca2+ when triggered, exrasystole triggered, can be due to simultaneous sympathetic & vagal stimulation, associated with ventricular arrhythmias associated with HF |
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Term
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Definition
| propagation around an anatomical or functional obstacle to reexcite origin, due to PAC through slow path triggering retrograde conduction through fast path, circuit length must be > than CVxAPD |
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Term
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Definition
| CV (conduction velocity) x APD (action potential duration) |
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Term
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Definition
| depolarization impulse travles across an unexcitable region, current may not be able to depolarize inexcitable zone, distal APs cause retrograde current, proximal tissue has repolarized and is depolarized by reflected AP |
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Term
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Definition
| requires spatial dispersion of repolarization, damage may cause epicardium to repolarize faster, current backflow due to voltage different between adjacent depolarized/repolarized cells, a new AP is generated if current reaches threshold, AVRT |
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Term
| Cinchonism (Quinidine, Salicylates) |
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Definition
| auditory and visual problems, GI upset, CNS symptoms |
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Term
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Definition
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Term
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Definition
| >7d, requires electrical/pharmacological cardioversion |
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Term
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Definition
| unsuccessful cardioversion |
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Term
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Definition
| initiate electrical impulses |
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Term
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Definition
| connect pacemaker cells to other conduction system, can slow conduction (AV and bundle of His) |
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Term
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Definition
| connect transitional cells to working myocardium, can rapidly slow contraction |
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Term
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Definition
| describe makeup of connexins on single cell |
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Term
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Definition
| describe makeup of connexins between cells |
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Term
| Absolute Refractory Period (ARP) |
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Definition
| Na+ channels have not been restored to active state |
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Term
| Effective Refractory Period (ERP) |
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Definition
| Na+ channels restored, muscles still do not response to stimulus |
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Term
| Relative Refractory Period (RRP) |
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Definition
| some cardiac cells have repolarization, can be stimulated |
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Term
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Definition
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Term
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Definition
| activation of the ventricles, obscures atrial repolarization |
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Term
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Definition
| repolarization of ventricles |
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Term
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Definition
| unknown function, maybe afterdepolarization of purkinje fibers |
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Term
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Definition
| duration of conduction from atrium through AV node |
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Term
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Definition
| occurs at end of QRs/beginning of ST segment |
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Term
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Definition
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Term
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Definition
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Definition
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