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39 Cards in this Set
- Front
- Back
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Antiarrhythmics
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suppress automaticity or alter the conductivity of the heart
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Arrhythmias involve changes to the automaticity or conductivity of the heart cells- factors
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electrolyte imbalances
decreased oxygen structural damage acidosis or waste product accumulation |
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lack of sufficient blood flow to the brain can cause syncope or precipitate stroke
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lack of sufficient blood flow to the myocardium can exacerbate atherosclerosis and cause angina or myocardial infarction
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Ibutilide
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very effective when given IV for rapid conversion of the AF
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IM quinidine
may convert AF effectively quinidine often the drug of choice for long-term stabilization |
Digoxin
has been effective in converting AF |
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dabigatran (pradaxa)
the anticoagulant of choice for prophylaxis in atrial fibrillation |
Flecainide
propafenone propranolol used to convert rapid svt |
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Esmolol
diltiazem verapamil IV to convert SVT with rapid ventricular response which could progress to AF |
it is usually recommended that AF be left untreated and anticoagulant therapy be started
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Adenosine
propranolol procainamide digoxin successful in treating supraventricular arrhythmias in children |
propranolol
digoxin long-term management for children |
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verapamil
should be avoided in children |
Class 1, 3, and 4
should not be used during lactation |
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Class 1 antiarrhythmics
stabilize the cell membrane by binding to sodium channels, depressing phase 0 of the action potential and changing the duration of the action potential these drugs are local anesthetics or membrane stabilizing agents preferable in tachycardia where the sodium channels are open more frequently these drugs bind more quickly to sodium channels that are open or inactive-ones that have been stimulated and are not yet repolarized |
drugs that block the sodium channels in the cell membrane during an action potential
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Class 1a
depress phase 0 of the action potential and prolong the duration of the action potential |
disopyramide-norpace-po
procainamide-pronestyl-IM-IV quinidine-po-im-iv-also given as a bolus injection in emergencies when monitoring is not available to document exact arrhythmia |
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Class 1b
depress phase 0 somewhat and actually shorten the duration of the action potential |
lidocaine-xylocaine-IM-IV-given as bolus injection in emergencies when monitoring is not available to document the exact arrhythmia
mexiletine-mexitil-po-adults only |
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Class 1c
markedly depress phase 0, with a resultant extreme slowing of conduction, but have little effect on the duration of the action potential |
flecainide-tambocor-po
propafenone-rythmol |
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absorbed in gi tract
hepatic metabolism excreted in the urine cross over to milk |
Contraindications
bradycardia heart block hf hypotension shock electrolyte disturbances hepatic/renal dysfunction |
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adverse effects
CNS: dizziness, drowsiness, fatigue twitching, mouth numbness, slurred speech,"", vision changes, and tremors that can progress to convulsions GI: change in taste, nausea, vomiting |
CV:proarryhmia hypotension, vasodilation, potential for cardiac arrest
rash loss of hair BMS |
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Moricizine
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increase in cardiac deaths because of its proarrhythmic effects
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Flecainide
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found to increase the risk of death in the CAST study
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risk for arrhythmias increases if these agents are combined with other drugs that are known to cause arrhythmias, such as digoxin and the beta-blocker
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quinidine competes for renal transport sites with digoxin, the combination of these two drugs can lead to increased digoxin levels and dig toxicity
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serum levels and toxicity of the class 1a increase if they are combined with cimetidine; extreme caution
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bleeding effects increase if they are used with anticoagulants
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quinidine requires slightly acidic urine for excretion
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avoid foods that alkalinize urine
citrus juices vegetables antacids milk products no grapefruit juice |
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Overview
Class 1 block sodium channels, depress phase 0 of the action potential, and generally prolong the action potential, leading to a slowing of conduction and automaticity |
Class 1 are membrane stabilizer; the adverse effects seen are related to the stabilization of the cell membranes, including those in the CNS and the GI tract
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Class 2
beta-adrenergic blockers that block beta-receptors, causing a depression of phase 4 of the action potential |
acebutolol-sectral-po
esmolol-brevibloc-IV propranolol-Inderal-PO-IV |
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competitively block beta-receptor sites in the heart and kidneys-result is
decrease in heart rate cardiac excitability cardiac output slowing of conduction through the AV node decrease in the release of renin |
stabilize excitable cardiac tissue
decrease blood pressure, which decreases the heart's workload and may further stabilize hypoxic cardiac tissue |
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these drugs are for SVT and PVC
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absorbed from the GI tract or have an immediate effect when given IV and undergo hepatic metabolism
excreted in urine food increases bioavailability of propranolol |
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contraindications
sinus bradycardia AV block cardiogenic shock hf asthma respiratory depression pregnancy with lactation caution; patients with diabetes and thyroid dysfunction renal/hepatic dysfunction |
Adverse
related to the effects of blocking beta-receptors in the sympathetic nervous system CNS; dizziness, insomnia, dreams, fatigue CV; hypotension, bradycardia, AV block, arrhythmias, and alterations in peripheral perfusion resp; bronchospasms and dyspnea GI; nausea, vomit, anorexia, constipation, diarrhea loss of libido decreased exercise tolerance alteration in blood glucose levels |
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drug-drug
adverse effects increases with verapamil-dose adjustment increased hypoglycemia-combined with insulin-monitor closely |
Overview
class 2 are beta-adrenergic receptor blockers that prevent sympathetic stimulation adverse effects related to class 2 are associated with blocking of the sympathetic response |
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Class 3
block potassium channels and slow the outward movement of potassium during phase 3 of the action potential, prolonging it all of these are proarrhythmic and have the potential of inducing arrhythmias |
amiodarone-cordarone-po-IV
dofetilide-tikosyn-po only ibutilide-corvert-IV sotalol-betapace-po only |
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amiodarone-cordarone-pacerone-po-IV
drug of choice for treating ventricular fibrillation or pulseless ventricular tachycardia in cardiac arrest situations |
absorption of sotalol is decreased by food.
they are all metabolized in the liver and excreted in the urine |
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Do not use ibutilide and dofetilide with aV block
caution; sotalol is proarrythmic |
caution
shock hypotension respiratory depression prolonged qt interval renal/hepatic disease |
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adverse effects
nausea, vomiting, GI distress weakness and dizziness hypotension HF, arrhythmias |
amiodarone has been associated with a potentially fatal liver toxicity
ocular abnormalties development of very serious cardiac arrhythmias |
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serious toxic effects if combined with
dig quinidine increased risk of proarrhythmias antihistamines phenothiazines tricyclic antidepressants |
increased risk of serious adverse effects if
dofetilide is combined with ketoconazole, cimetidine, or verapamil sotalol may have a loss of effectiveness if it is combined with NSAIDs, aspirin, or antacids |
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overview
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Class 3 block potassium channels and prolong phase 3 of the action potential
amiodarone is the drug recommended for use during life support measures, it is associated with serious to potentially fatal hepatotoxicity |
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class 4
block the movement of calcium ions across the cell membrane, depressing the generation of action potentials and delaying phases 1 and phases 2 of repolarization, which slows automaticity and conduction |
include two calcium channel blockers
-diltiazem-iv -verapamil-iv-when used as an antiarrhythmic also antihypertensives to treat angina |
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highly protein bound
metabolized in the liver, excreted in the urine cross the placenta and enter breast milk |
Contraindications
sick sinus syndrome heart block pregnancy, lactation HF hypotension caution idiopathic hypertrophic subaortic stenosis |
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AE
related to their vasodilation of blood vessels throughout the body CNS: dizziness, weakness, fatigue, depression, ha GI: upset, nausea, vomiting hypotension hf shock arrhythmias edema-has been reported |
verapamil-many drug-drug-
increased risk of cardiac depression with beta blockers; additive AV slowing with digoxin, increased serum levels and toxicity of dig, carbamazepine, prazosin, and quinidine, increased respiratory depression with atracurium, pancuronium, and vecuronium decreased effects if combined with calcium products or rifampin |
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risk of sever cardiac effects if these drugs are given IV with 48 hours of IV beta-adrenergic drugs
avoid the combination |
Diltiazem can increase the serum levels and toxicity of cyclosporine if taken concurrently
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Overview
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Class 4 are calcium channel blockers that shorten the action potential , disrupting ineffective rhythms and rates
constantly monitor pt while being stabilized and throughout course of therapy to detect the development of arrhythmias or other adverse effects associated with alteration of the action potentials of other muscles or nerves |
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Other antiarrhythmics
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adenosine
used to convert SVT to sinus rhythm if vagal maneuvers have been ineffective short duration of action very few adverse effects slows conduction through the av node, prolongs the refractory period, and decreases automaticity in the AV node-IV-with continuous monitoring |
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Digoxin
slows calcium from leaving the cell, prolonging the action potential and slowing conduction and heart rate atrial arrhythmias positive inotropic effect may eliminate the cause of some arrhythmias as hypoxia is resolved and waste products are removed more effectively |
Dronedarone
has properties of all four classes atrial arrhythmis reduce the risk of hospitalization in pts with paroxysmal or persistent AF of flutter who have risks factors for cv disease and who are in sinus rhythm or are scheduled to be converted to sinus thythm po bid avoid grapefruit juice most common hf prolonged qt interval nausea diarrhea rash fetal abnormalities |
