B4-017 CBCL: Dysrhythmias Flashcards
1
Q
A
normal sinus rhythm
2
Q
normal conduction velocity: PR interval
A
.2s
5 small boxes
3
Q
normal conduction velocity: QRS
A
.12s
3 small boxes
4
Q
normal conduction velocity: QT interval
A
.44s
5
Q
- time between start of SA node and AV firing
- occurs due to “pause” effect of AV node
A
PR interval
6
Q
time to depolarize all of the ventricular myocardium
A
QRS
7
Q
time to repolarize all of ventricular myocardium
A
QT interval
8
Q
A
first degree AV block
9
Q
A
2nd degree AV block
Mobitz I
10
Q
A
2nd degree AV block
Mobitz 2
11
Q
- progressive lengthening of PR until a beat is dropped
- variable RR with a pattern
- regularly irregular
- usually asymptomatic
A
2nd degree AV block
Mobitz I
12
Q
- dropped beats that are not preceded by a change in PR interval
- indicates structural issue: ischemia, fibrosis, sclerosis
- requires pacemakers
A
2nd degree AV block
Mobitz II
13
Q
- P waves and QRS complexes are rhythmically dissociated
- atria and ventricles beat independently of each other
- atrial rate> ventricular rate
- usually requires pacemaker
A
complete/ 3rd degree heart block
14
Q
A
complete/3rd degree heart block
15
Q
A
junctional rhythm
16
Q
A
sinus bradycardia
17
Q
A
asystole
check lead placement
18
Q
A
sinus tachycardia
19
Q
A
atrial flutter
20
Q
A
atrial fibrillation
21
Q
A
supraventricular tachycardia
22
Q
A
monomorphic ventricular tachycardia
23
Q
A
polymorphic ventricular tachycardia
24
Q
A
ventricular fibrillation
25
torsades de pointes
26
irregularly irregular with no distinct p wave
atrial fibrillation
27
rapid succession of identical, consecutive artial depolarization waves causing a "sawtooth" appearance
atrial flutter
28
* regular rhythm and rate
* >100 bpm
* QRS > 120ms
* commonly due to cardiomyopathy/ishchemia after infarction
* high risk of sudden cardiac death
ventricular tachycardia
29
treatment of torsades de pointes
magnesium
30
* polymorphic v tach
* shifting sinusoidal waveforms
* may progress to v fib
* long QT interval predisposes risk
torsades de pointes
31
what causes drug induced long QT?
anti-**A**rrythmics
anti-**B**iotics
anti-**C**hychotics
anti-**D**epressants
anti-**E**metics
anti-**F**ungals
**N**avir (protease inhibitors)
**O**piods
| ABCEDEF + NO
32
* disorganized rhythm with no identifiable waves
* fatal without immediate defibrillation
ventricular fibrillation
33
* prolonged PR interval
* benign and asymptomatic
first degree heart block
34
classes of drugs used for rate control
* B-blocker
* Ca+ channel blockers
* digoxin
35
classes of drugs used for rhythm control
* Na+ channel blockers
* K+ channel blockers
36
class 1 of antiarrhythmic drugs are
Na+ channel blockers
37
class 2 antiarrhythmic drugs are
B blockers
38
class 3 antiarrhythmic drugs are
K+ channel blockers
39
class 4 antiarrhythmic drugs are
Ca+ channel blockers
40
Drugs in class IA
* Procainaminde
* Quinidine
* Disopyramide
| The **qu**een **pro**claims **Diso's pyramid**
41
Drugs in class 1B
* Lidocaine
* Mexiletine
42
drugs in class 1C
* Flecainide
* Propafenone
* Moricizine
43
drugs in class 2
* propranolol
* metoprolol
* esmolol
44
drugs in class 3
* amiodarone
* dronedarone
* sotalol
* ibutilide
* dofetilide
45
drugs in class 4
* verapamil
* diltiazem
46
other antiarrhythmic drugs
* adenosine
* digoxin
* magnesium
47
what class of drugs decrease the slope for phase 4 depolarization in SA node
Class 1
48
what class of drugs decrease the heart rate but elevating the threshold for excitation
class 1
49
* moderate Na+ channel block
* dissociate with intermediate kinetics
* prolong APD
class 1A
50
* mild Na+ channel block
* fast dissociation
* shorten APD
class 1B
51
* strong Na+ channel block
* slow dissociation
* minimal effect on APD
class 1C
52
has ganglion blocking activity which reduces peripheral vascular resistance and can cause hypotension
| especially IV
procainamide
53
long term therapy can cause a reversible lupus type syndrome
* rash
* arthralgia
* arthritis
* pericarditis
procainamide
54
does procainamide elevate digoxin levels?
no
55
least useful class 1A drug due to short half life and adverse effects
procainamide
56
drug of second or third choice for sustained ventricular arrhythmias associated with myocardial infarction
procainamide
57
similar to procainamide, with modest antimuscarinic effect
quinidine
58
* blocks a-adrenergic receptors to cause vasodilation
* marked hypotension and reflex tachycardia
quinidine
59
# adverse effects
* increase plasma digoxin
* thrombocytopenia
* adverse GI effects
quinidine
60
rarely used because of cardiac and extracardiac adverse effects and better bioavailbility of other drugs
quinidine
61
similar effects to quindine and procainamide, but more antimuscarinic effects
disopyramide
62
# adverse effects:
* urinary retention
* dry mouth, blurred vision, constipation
* worsening of glaucoma
| atropine-like activity
disopyramide
63
* not used very often because of antimuscarinic effects
* only approved in USA to treat ventricular arrhythmias
disopyramide
64
must be given IV due to high first-pass hepatic metabolism
lidocaine
65
* treats unstable v tach
* relatively uneffective for atrial flutter or fibrillation
lidocaine
66
low incidence of toxicity and high degree of effectiveness
lidocaine
67
lidocaine analog, but resistant to first-pass metabolism
mexiletine
68
* useful for ventricular arrythmias
* can be used off label for diabetic neuropathy
mexiletine
69
# adverse effects
predominantly neurologic:
* tremor
* blurred vision
* lethargy
* nausea
mexiletine
70
increase mortality from cardiac arrest or arrhythmic sudden death in patients with recent MI
Class 1C antiarrhythmics
71
* no QT prolongation
* no antimuscarinic effects
* used to treat supraventricular arrhythmias
* effictive in suppressing PVCs
flecainide
72
* blocks Na+ channels, weak B blocker
* has metallic taste
* may exacerbate arrythmias and cause constipation
propafenone
73
* antiarrhythmic phenothatzine derivative
* used for ventricular arrhythmias
* withdrawn from US market
moricizine
74
* frequently used for rate control
* treat supraventricular and ventricular arrythmias causes by SNS
* prevent ventricular fibrillation
| 2
propranolol (nonselective)
atenolol (b1 selective)
75
* short acting drug
* IV
* used for acute tachycardias occurring during surgery
esmolol (b1 selective)
76
harmful effect of Class 2: b-blockers
negative inotrope
77
* dimish SNS activation of the heart and vessels
* dimish cardiac workload
* clear mortality benefit in CHF
Class 2: b- blockers
78
* oral or IV
* treats atrial fibrillation
amiodarone
79
* prolongs AP duration by blocking K+ channels
* decreases rate of firing in pacemaker cells by blocking Na+ channels
* blocks a- and b- adrenergic receptors and Ca+ channels
* bradycardia
amiodarone
80
causes peripheral vasodilation after IV administration
amiodarone
81
can cause pulmonary fibrosis
amiodarone
82
can cause gray-blue skin discoloration
amiodarone
83
can cause corneal microdeposits and blindess
amiodarone
84
can cause hypo or hyper thyroidism
amiodarone
85
* long half life
* measurable even after a year
amiodarone
86
* metabolized by CYP3A4
* can elevate digoxin or warfarin
amiodarone
87
structural analog of amiodarone, no iodine
dronedarone
88
can cause severe liver toxicity to the point of requiring transplant
dronedarone
89
"black box" FDA warning regarding an increased risk of death, stroke, and heart failure in patients with decompensated heart failure or permanent a fin
dronedarone
90
* non selective b-blocker that prolongs ADP
* treatment of life-threatening ventricular arrhythmias in **pediatrics**
sotalol
91
dofetilide is administed
orally
92
ibutilide is administered
IV
93
* block rapid component of delayed rectifier K+ current to slow cardiac repolarization
* good to restore normal sinus rhythm in a fib or flutter
| 2
dofetilide or ibutilide
94
* orally active
* block L type Ca+ channels
* rate control for a fib
| 2
verapamil, diltiazem
95
opens inward rectifier K+ channels --> hypopolarization
adenosine
96
* inhibits L type calcium channels
* mainly effects AV node, not SA node
* very short half life
* treats paroxysmal supraventricular tachycardia
adenosine
97
# adverse effects
* flushing
* SOB
* chest burning
* headache
* hypotension
* nausea
* paresthesia
adenosine
98
* potent and selective NaKATPase inhibitor
* positive inotrope
digoxin
99
* stimulates vagus nerve to decrease heart rate without affecting blood pressure
* used in a fib
digoxin
100
* very narrow therapeutic window
* many drug-drug interactions
digoxin
101
drugs that enhance digoxin toxicity
* quinidine
* amiodarone
* captopril
* verapamil
* dilitiazem
* cyclosporine
102
* GI: nausea, vomiting, diarrhea, abdominal discomfort
* Cardiac: can lead to almost all arryhthmias
digoxin toxicity
103
administed parenterally
magnesium
104
used to prevent/treat torsades de pointes
and digoxin induced arrhythmias
magnesium
105
* effective mainly in the treatment of ventricular arrhythmias
* stable v tach
magnesium
