MIDTERM 03 - Antiarrhythmic Drugs Flashcards
1
Q
System composed of autorhythmic fibers; acts as a pacemaker that sets the rhythm of electrical excitation
A
Cardiac conduction system
2
Q
Node located in the right atrial wall; a natural pacemaker that is faster than the pace of other autorhythmic fibers
A
Sinoatrial (SA) node
3
Q
If the sinoatrial node (100x/min) fails, the __________ node takes over (40-60x/min)
A
Atrioventricular (AV) node
4
Q
If the atrioventricular (AV) node fails, other __________ fibers take over (20-35x/min)
A
Autorhythmic
5
Q
A recording of electrical signals on the skin generated by cardiac action potentials
A
Electrocardiogram (ECG)
6
Q
An instrument used to record ECG
A
Electrocardiograph
7
Q
Signifies atrial depolarization before atrial contraction (Parts of normal electrocardiogram)
A
P wave
8
Q
Phase 0 (rapid upstroke) (Parts of normal electrocardiogram)
A
P wave and QRS complex
9
Q
Signifies ventricular depolarization before ventricular contraction (Parts of normal electrocardiogram)
A
QRS complex
10
Q
Signifies ventricular repolarization before ventricular relaxation (Parts of normal electrocardiogram)
A
T wave
11
Q
Phases 1-2 (initial repolarization and plateau) (Parts of normal electrocardiogram)
A
T wave
12
Q
Refers to the conduction time from the beginning of atrial excitation to the beginning of ventricular excitation; may be prolonged in coronary heart disease or RF
A
PQ interval
13
Q
Refers to the time when the ventricular contractile fibers are depolarized during the plateau phase of the action potential; may be elevated in acute MI and depressed in myocardial ischemia
A
ST interval
14
Q
Refers to the time from beginning of ventricular depolarization to the end of ventricular repolarization; may be prolonged in heart injury
A
QT interval
15
Q
Refers to the continuous ambulatory electrocardiography
A
Holter monitoring
16
Q
A battery-operated monitor that records an ECG continuously for 24 hours
A
Holter monitor
17
Q
Refers to the loss of cardiac rhythm, especially the irregularity of heartbeat
A
Arrhythmia
18
Q
Increased firing of tissues with spontaneous pacemaker activity (Abnormalities in impulse formation)
A
Enhanced automaticity
19
Q
Normal cardiac action potential followed by an abnormal afterdepolarization (Abnormalities in impulse formation)
A
Afterdepolarizations and triggered automaticity
20
Q
Decrease in conduction (Abnormalities in impulse formation)
A
Block
21
Q
Impulse reenters and excites areas of the heart more than once (Abnormalities in impulse formation)
A
Reentry
22
Q
Includes atrial fibrillation (AF), atrial flutter, and paroxysmal supraventricular tachycardia (PSVT) (Types of arrhythmia)
A
Supraventricular tachyarrhythmias
23
Q
Includes premature ventricular contractions (PVCs), ventricular tachycardia (VT), and ventricular fibrillation (VF) (Types of arrhythmia)
A
Ventricular arrhythmias
24
Q
Includes sinus bradyarrhythmias and AV block (Types of arrhythmia)
A
Bradyarrhythmias
25
Due to reentry; extremely rapid (400-600 atrial beats/min); no P wave (Types of supraventricular tachyarrhythmias)
Atrial fibrillation (AF/Afib)
26
Due to reentry; rapid (270-330 atrial beats/min); 2-3 P waves in sawtooth pattern followed by QRS-T (Types of supraventricular tachyarrhythmias)
Atrial flutter
27
Due to reentry; is rapid and regular; P wave merged with T wave (Types of supraventricular tachyarrhythmias)
Paroxysmal supraventricular tachycardia (PSVT)
28
Has an unknown mechanism; has single ventricular beats that fall earlier than the next anticipated supraventricular beat (Types of ventricular arrhythmias)
Premature ventricular contractions (PVCs)
29
Due to reentry, afterdepolarization, and triggered automaticity; is rapid and regular; three or more repetitive PVCs occurring at a rate greater than 100 beats min (Types of ventricular arrhythmias)
Ventricular tachycardia (VT/VTach)
30
Due to reentry; immeasurable rate and irregular rhythm; the most serious of all arrhythmias (Types of ventricular arrhythmias)
Ventricular fibrillation (VF/Vfib)
31
Due to depressed automaticity; slow (<60 beats/min) and regular (Types of bradyarrhythmias)
Sinus bradyarrhythmias
32
__________ usually does not require treatment (Types of sinus bradyarrhythmias)
Physiologic bradycardia
33
__________ (e.g. sick sinus syndrome) is treated with a pacemaker (Types of sinus bradyarrhythmias)
SA node dysfunction
34
Due to block; normal SA activation and atrial systole but delayed or absent ventricular activation; has 3 degrees (Types of bradyarrhythmias)
AV block
35
Prolonged PR interval (Degrees of AV block)
1st degree
36
Prolonged PR interval with missing QRS complexes (Degrees of AV block)
2nd degree
37
Atrial and ventricular activation are independent (Degrees of AV block)
3rd degree
38
Inhibits Na+ channel; decreases excitability and conduction velocity (Classes of antiarrhythmics)
Class I antiarrhythmics
39
Slows phase 0 depolarization in ventricular muscle fibers (Types of Class I antiarrhythmics)
Class IA antiarrhythmics
40
Procainamide, quinidine, and disopyramide are all examples of Class __________ antiarrhythmics
IA
41
Derivative of procaine; used as an acute treatment of AFib, VFib, and VTach in MI (Examples of Class IA antiarrhythmics)
Procainamide (PO, IV, IM)
42
Rarely used; used for maintenance of sinus rhythm in patients with atrial flutter and prevention of recurrence of VTach or VFib (Examples of Class IA antiarrhythmics)
Quinidine (PO)
43
Has modest antimuscarinic and alpha antagonist effect (Examples of Class IA antiarrhythmics)
Quinidine (PO)
44
Used for maintenance of sinus rhythm in patients with atrial flutter and prevention of recurrence of VTach or VFib (Examples of Class IA antiarrhythmics)
Disopyramide (PO)
45
Blocks open Na+ blocker and K+ channels; sometimes used in hypertrophic cardiomyopathy (Examples of Class IA antiarrhythmics)
Disopyramide (PO)
46
Most common ADR of quinidine (PO)
Diarrhea
47
ADR of quinidine characterized by headache, dizziness, and tinnitus
Cinchonism
48
Shortens phase 3 repolarization in ventricular muscle fibers (Types of Class I antiarrhythmics)
Class IB antiarrhythmics
49
Lidocaine and mexiletine are all examples of Class __________ antiarrhyhmics
IB
50
DOC for termination of VT (Examples of Class IB antiarrhythmics)
Lidocaine (IV)
51
DOC for prevention of VF after cardioversion in the setting of acute ischemia (Examples of Class IB antiarrhythmics)
Lidocaine (IV)
52
One of the least cardiotoxic (Examples of Class IB antiarrhythmics)
Lidocaine (IV)
53
Seizures due to lidocaine must be treated with __________
Diazepam
54
Oral congener of lidocaine; used for ventricular arrythmias (Examples of Class IB antiarrhythmics)
Mexiletine (PO)
55
Oral congener of lidocaine that has reduced 1st pass effect (Examples of Class IB antiarrhythmics)
Mexiletine (PO)
56
Slows phase 0 depolarization in ventricular muscle fibers (Types of Class I antiarrhythmics)
Class IC antiarrhythmics
57
Moricizine, flecainide, and propafenon are all examples of Class __________ antiarrhythmics
IC
58
A phenothiazine derivative; used as chronic treatment of ventricular arrhythmias (Examples of Class IC antiarrhythmics)
Moricizine (PO)
59
Used for maintenance of sinus rhythm in AFib; used as chronic treatment of PSVT (Examples of Class IC antiarrhyhmics)
Flecainide (PO)
60
Has some structural similarities to propranolol; used for maintenance of sinus rhythm of AFib and for supraventricular tachyarrhythmias (Examples of Class IC antiarrhythmics)
Propafenone (PO)
61
Has beta blocking activity (Configurations of propafenone)
S-(+)-propafenone
62
RyR2 Ca2+ channels-blocking activity (Configurations of propafenone)
R-(-)-propafenone
63
Blocks β-receptors; inhibits phase 4 depolarization in SA and AV nodes; used as acute and chronic treatment of VT without structural heart disease (Classes of antiarrhythmics)
Class II antiarrhythmics
64
Acebutolol, esmolol, and propranolol are all Class __________ antiarrhythmics
II
65
DOC for chronic treatment to prevent arrhythmias in congenital LQTS and CPVT (Class II antiarrhythmics) (NPM)
Nadolol (preferred), Propranolol, Metoprolol
66
Has an ultrashort half-life of 9 minutes; used as an acute treatment to control rate in AF (Class II antiarrhythmics)
Esmolol (IV)
67
Inhibits K+ channels; prolongs phase 3 repolarization in ventricular muscle fibers (Classes of antiarrhythmics)
Class III antiarrhythmics
68
Amiodarone, ibutilide, dofetilide, and sotalol are all examples of Class __________ antiarrhythmics
III
69
A structural analog of thyroid hormone; used for maintenance of sinus rhythm in AFib and treatment of VFib and VTach in MI (Examples of Class III antiarrhythmics)
Amiodarone (PO, IV)
70
Has a broad spectrum; having class I-IV activity (Examples of Class III antiarrhythmics)
Amiodarone (PO, IV)
71
DOC for acute treatment of VT or VF causing cardiac arrest (Examples of Class III antiarrhythmics)
Amiodarone (PO, IV)
72
Pulmonary fibrosis due to amiodarone (PO) should be treated with __________
Glucocorticoids
73
A noniodinated structural analog of amiodarone used as chronic treatment in restoring sinus rhythm in AF and atrial flutter (Examples of Class III antiarrhythmics)
Dronedarone (PO)
74
Has class I-IV activity; is both a substrate and inhibitor of CY3A4 (Examples of Class III antiarrhythmics)
Dronedarone (PO)
75
Dronedarone (PO) has a __________; meaning it is not to be used in acute decompensated or advanced HF
Black box warning
76
Blocks rapid delayed rectifier K+ channel; has no extracardiac effects (Examples of Class III antiarrhythmics)
Dofetilide (PO)
77
Used for the acute conversion of atrial flutter and AFib to normal sinus rhythm (Examples of Class III antiarrhythmics)
Ibutilide (IV)
78
Adverse drug reaction (ADR) of ibutilide (IV), dofetilide (PO), and sotalol (PO)
Torsades de pointes
79
Used for the maintenance of normal sinus rhythm in patients with AFib (Examples of Class III antiarrhythmics)
Dofetilide (PO)
80
Non-selectively blocks beta receptors (class II) and prolongs AP duration (class III) activity (Examples of Class III antiarrhythmics)
Sotalol (PO)
81
Has beta blocking activity (Configurations of sotalol)
L-sotalol
82
Has AP-prolonging activity (Configurations of sotalol)
D- & L-sotalol
83
Used for chronic treatment to prevent AF, VT, and VF; decreases threshold for cardiac defibrillation (Examples of Class III antiarrhythmics)
Sotalol (PO)
84
A quaternary ammonium compound used as treatment and prevention of VF (Examples of Class III antiarrhythmics)
Bretylium
85
Blocks Ca2+ channel; inhibits action potential in SA and AV nodes (Classes of antiarrhythmics)
Class IV antiarrhythmics
86
Verapamil and diltiazem are all examples of Class __________ antiarrhythmics
IV
87
Blocks activated and inactivated L-type Ca2+ channels; suppresses EADs and DADs (Examples of Class IV antiarrhythmics)
Verapamil (PO, IV)
88
Used as a 2nd line drug as acute treatment to terminate SVT; has dose-related cardiotoxicity (Examples of Class IV antiarrhythmics)
Verapamil (PO, IV)
89
Used for PSVT; has less cardiac ADRs than verapamil (Examples of Class IV antiarrhythmics)
Diltiazem (IV)
90
A nucleoside; DOC for acute treatment of PSVT (Other antiarrhythmic drugs)
Adenosine (IV)
91
The therapeutic goal of adenosine (IV)
Transient asystole (<5 sec)
92
Has muscarinic (vagotonic) activity; causes atrial tachycardia with AV block (Other antiarrhythmic drugs)
Digoxin
93
Used for the acute treatment of torsades de pointes and digitalis-included arrhythmia (Other antiarrhythmic drugs)
Magnesium sulfate (IV)
94
A surgically implanted device that sends out small electrical currents to stimulate the heart to contract; it restores and maintains normal heart rhythm
Artificial pacemakers
95
From closed to open state (Ionic basis of membrane potential)
Activation
96
Closed but cannot be reavtivated (Ionic basis of membrane potential)
Inactivation
97
Reversal of activation (Ionic basis of membrane potential)
Deactivation
98
Atrial myocytes (Fast or slow-response cell)
Fast-response cell
99
Ventricular myocytes (Fast or slow-response cell)
Fast-response cell
100
Purkinje fibers (Fast or slow-response cell)
Fast-response cell
101
SA node (Fast or slow-response cell)
Slow-response cell
102
AV node (Fast or slow-response cell)
Slow-response cell
103
Depolarization; rapid increase in Na+ current (Ina); increase in inward rectifier K+ current (Ik1) (Phases in fast-response cells)
Phase 0 (Rapid upstroke)
104
Rapid decrease in inward Na+ current (Ina); increase in transient outward K+ current (Ito) (Phases in fast-response cells)
Phase 1 (Initial repolarization)
105
Increase in Ca2+ current; slow activation of L-type Ca2+ channels (Ica,L) (Phases in fast-response cells)
Phase 2 (Plateau)
106
Decrease in Ca2+ current; increase in K+ current (Phases in fast-response cells)
Phase 3 (Final repolarization)
107
-90 mV; stable; background K+ conductance (Phases in fast-response cells)
Phase 4 (Resting membrane potential)
108
Period from the beginning of action potential (phase 0) to midway of repolarization (phase 3)
Effective refractory period
109
Period from the end of effective refractory period and complete repolarization
Relative refractory period
110
Depolarization; increase in Ca2+ current (Phases in slow-response cells)
Phase 0 (Upstroke)
111
Decrease in Ca2+ current; activation of delayed rectifier K+ current (Ik) (Phases in slow-response cells)
Phase 3 (Final repolarization)
112
Less negative and less stable; depolarization; increase in Ca2+ current (Phases in slow-response cells)
Phase 4 (Diastole/Maximum diastolic potential)
113
Enhances pacemaker/funny current (Sympathetic or parasympathetic)
Sympathetic
114
Enhances Ca2+ channel activity (Sympathetic or parasympathetic)
Sympathetic
115
Enhances ACh-sensitive K+ current (Sympathetic or parasympathetic)
Parasympathetic
116
Refers to the refractory period extension beyond phase 3; due to L-type Ca2+ channel inactivation
Postrepolarization refractoriness
117
Selectively blocks open "funny" current (If) in SA node (Other antiarrhythmic drugs)
Ivabradine
118
Blocks early Ina, late InaL, and delayed rectifier K+ current (Ikr) channels; currently undergoing clinical trials (Other antiarrhythmic drugs)
Ranolazine
119
Blocks early Ina, late InaL, and ACh-sensitive K+ (Ikach) channels; used for rapid termination of AF (Other antiarrhythmic drugs)
Vernakalant (IV)
