Ch 48 Flashcards
What are the two types of dysrhythmias
Tachydysrhythmias
Bradydysrhythmias
In severe forms of dysrhythmias what can happen to the heart
Heart can be disabled so no output occurs
Drugs that treat dysrhythmias can cause dysrhythmias so what’s happening to the use of these drugs
Decline due to increased risk/benefit effects
Dysrhythmias are a result of what
Alteration in electrical impulses that regulate cardiac rhythm
What are the 4 steps to the pathway and timing of an impulse conduction in a healthy heart
Impulse originates in SA node
Spreads rapidly through atria
Pass slowly through av node
Spread rapidly through the ventricle via the hispurkinje system
Dysrhythmias are a cause of either disturbances of impulse formation occurring in either SA or av nodes, purkunjie system or
Disturbances of conduction like av block
What are 6 factors that can cause dysrhythmias
Hypoxia Reduced coronary flow Electrolyte imbalance Cardiac surgery Myocardial infarction Anti dysthymia drugs (why they shouldn't be used)
What’s more dangerous than supra ventricular dysrhythmias
Ventricular dysrhythmias
Vaughan Williams classification of antidysrhythmic drugs
Class I: quinidine Class II: propranolol Class III: bretylium Class IV: cardizem Others: digoxin
Class 1: quinidine does what
Blocks sodium channels and delays ventricular repolarization
Class III: bretylium are what and do what
Potassium channel blockers
Delay repolarization
Class IV: cardizem is what and does what
Calcium channel blockers
Reduces as node activity
What are 3 adverse effects of quinidine
Diarrhea
Cinchonism
Cardio toxicity
Lidocaine (xylocaine) blocks sodium channels, accelerates repolarization and has what 3 adverse effects
CNS effects
Confusion
Paresthesias
Propranolol is a non selective beta adrenergic used for tachydysrhythmias and has what 4 adverse effects
Broncho spasm
Heart failure
Av block
Sinus arrest
