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51 Cards in this Set

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What is the class of arrhythmic drug that suppresses phase 0 upswing in purkinje and myocardial fibers and shows a marked slowing of condution in all cardia tissues? What is the prototype?
Class 1c. Prototype, Flecainide
This drug is used in treatment of various arrhthmias that originate in ventricles of atria.
Class 1a - Quinidine
This drug is used in treatment of ventricular arrhythmias arising during myocardial ischemia. It is the drug of choice in emergency treaatment of cardiac arrhythmias and is the least cardiotoxic.
Class 1b, Lidocaine
This drug is used in treatment of ventricular arrhythmias such as ventricular tachycardia.
Class 1c, Flecainide
What are the Cardiac and Extracardiac effects of Class I Arrhythmic drugs?
Cardiac: Tendency to aggravate or initiate cardiac rhythm abnormalities while controlling one type of rhythm abnormality (proarrhythmic effect).
Extracardiac: CNS disturbances such as dizziness, nausea and visual disturbances.
This drug is used less often and with more caution than before.
Cardiac AP is divided into several phases. This phase is a brief period of repolarization due to exit of K+ from cell.
Phase 1
This refers to significant deviation from normal cardiac rhythm.
Arrhythmia
True or False. Arrhythmia affects 50% of patients treated with digitalis, 25% of anethetized patients, and 70% of pts with acute MI.
False. Arrhythmia affects 25% of pts treated with digitalis, 50% of anesthetized pts, and 80% of patients with acute MI.
What are three mechanisms of Cardiac Arrhythmias?
1. Abnormal automaticity/impulse formation
2. Abnormalities in impulse conduction
3. Simultaneous abnormalities of impulse generation and conduction
These type of cells in the sinoatrial (SA) (sinus) node depolarize spontaneoulsly to generate action potential (AP): dominate and control cardiac rhythm in normal heart.
Pacemaker cells
AP spread in a timely way through the atria via atrial muscle cells to these.
AV (Atrioventricular) node
The bundle of HIS is made up of conducting cells known as ________, which distribute AP ventricular muscle cells.
Purkinje fibers
From AV node, AP transmitted to ventricles via specialized conducting system known as what?
Bundle of HIS
The fraction delay at the ________ allows time for the atrial contraction that helps fill the ventricles with blood.
AV node
This is when the heartrate is <60 beats per minute.
Bradycardia
This is when the heart rate is > 100 beats per minute.
Tachycardia
Cardiac AP is divided into several phases. This phase is rapid depolarization due to sudden influs of Na +.
Phase 0
What are 3 things arrhythmias are named for?
1. origin
2. nature of disturbed heartbeat
3. impairment of cardiac conduction
Example: Ventricular arrthythmias originate in ventricles
- Supraventricular arrhythmias origin is in atria, AV node or upper purnje fibers.
Name 5 common classifications of arrhythmias?
1. Sinus arrhythmias
2. Supraventricular arrhythmias
3. Atrioventricular junctional arrhythmias
4. Conduction disturbances
6. Ventricular arrhythmias
This classification of arrhythmia involves Sinus tachycardia, sinus bradycardia and/or sick sinus syndrome.
Sinus arrhythmia
This classification of arrhythmia can include atrial fibrillation and flutter, atrial tachycardia and premature atrial contractions.
Supraventricular arrhythmias
This classification of arrhythmia can include junctional rhythm, and junctional tachycardia.
Atrioventricular junctional arrhythmias.
This classification of arrhythmias can include atrioventricular block, bundle branch block, and fascicular block.
Conduction disturbances
The classification of these arrhythmias can include, premature ventricular contractions, ventricular tachycardia, and ventricular fibrillation.
Ventricular arrhythmias.
These classifications of drugs block Na+ channels
IA, IB, IC
These classifications of drugs block beta adrenoreceptors
II
These classifications of drugs block K+ channels.
III
These classifications of drugs block Ca++ channels.
IV
These drugs bind to open (activated) or closed (inactivated) Na+ channels to cause normalization of Na+ entry.
Sodium channel blockers.
What is the class of arrhythmic drug that binds to open and inactivate Na+ channels to prevent Na+ influx? What is the prototype?
Class 1a - prototype Quindine (anti malaria)
What is the class of arrhythmic drug that blocks both activated and inactivated Na+ channels? It shortens phase 3 repolarization and decreases duration of AP. What is the prototype?
Class 1b. Prototype, Lidocaine
Cardiac AP is divided into several phases. This phase is a plateau due to opening of Ca2+ channels, Efflux of K+ ions in hase 1 balances the influx of Ca2+, no net charge-plateau which enables heart to rest and fill with blood - diastole.
Phase 2
The cardiac AP is divided into several phases. This phase is when repolarization is completed by unopposed efflux of K+ as Ca2+ channels close.
Phase 3
The cardiac AP is divided into several phases. This phase is slow spontaneous depolarization due to leak of Na+ ions into cell plus gradual decrease in K+ exit; accumulation of positive charge causes cell to reach threshold and enter phase 0.
Phase 4
This class of antiarrhythmic drugs decrease excitatory effects of sympathetic nervous system, slow down heart rate and contractility (negative chronotropic and ionotropic effect) and conduction through myocardium.
Class II: Beta-Blockers
What is the prototype for Class II antiarrhythmic drugs?
Propranolol (Beta Blocker)
This class of antiarrhythmic drugs decrease excitatory effects of sympathetic nervous system, slow down heart rate and contractility (negative chronotropic and ionotropic effect) and conduction through myocardium.
Class II: Beta-Blockers
True or False - Class II Beta Blockers are not as safe as Class I Sodium channel blockers.
False, Beta Blockers are safer than Sodium channel blockers.
One of this antiarrhythmic drugs side effects include othostatic hypotension. A precaution would be to decrease exercise and stress level because of a decrease in HR.
Class II - Beta Blocker
This antiarrhythmic drug is used in treatment of arrthythmias originating in atria and AV nodes and is the mainstay in treatment of arrhythmias.
Class II - Beta Blockers
What are the cardiac and extracardiac effects of Class III drugs?
Cardiac = antifibrillatory effect
Extracardiac = beta clockers, therefore potential to cause postural hypotension
These drugs have selective ability to block calcium entry into myocardial and vascular smooth muscle cells.
Class IV - Calcium channel blockers
This drugs prototype is Nifedipine.
Class IV - Calcium channel blockers
This drug decreases the rate of discharge of the SA node and inhibits conduction through the AV node.
Class IV - Calcium channel blockers
This drug is used in treatment of arrhythmias cuased by atrial dysfunction such as suproventricular tachycardia and atrial fibrillation.
Class IV - calcium channel blocker
What are some non-pharmacological approaches to treatment of arrhythmias?
Pacemakers, Catheter ablation (destroy tissue contributing to tachycardia), Electrical therapy, Cardioversion (implantable cardioverter defribillator, Surgery
This drug is used in the treatment of ventricular arrhythmias, ventricular fibrillation supraventricular arrhythmias.
Class III - K+ Blockers
This class of antiarrhythic drugs block potassium channels and prolong duration of AP without altering phase 0.
Class III - K+ Blockers
The prototype for this anti arrhythmic drug is Sotalol.
Class III - K+ Blocker
The advantages to this antiarrhythmic drug is that it affects both atrial and ventricular problems and it is safe compared with Class I drugs.
Class III K+ blockers
This class of antiarrthythmic drugs prolong repolarization.
Class III K+ Blockers