Pharm --Heart Phys/Antiarrhythmic Flashcards

1
Q

This class of antiarrhythmics work on voltage gated Na channels (activated state)

A

Class 1 – Na channel blockers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

This class of antiarrhythmics work on voltage gated K channels

A

Class 3 – K channel blockers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

This class of antiarrhythmics work on voltage gated Ca channels

A

Class 4 – Ca channel blockers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

This class of antiarrhythmics work on sympathetic innervation?

A

Class 2 – B-blockers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

This class of antiarrhythmics work on voltage gated Na channels by depressing phase 0 and proloinging repolarization?

A

Class 1A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

This class of antiarrhythmics work on voltage gated Na channels shortens repolarization?

A

Class 1B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What parts of the heart exhibit fast-response action potentials?

A

Myocardium: Atrium, Ventricle, His-Purkinje

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What parts of the heart exhibit slow-response action potentials?

A

SA node, AV node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What heart cells have excitation threshold around:

  • -65mV
  • -35mV
A
  • -65mV = myocardial cells

- -35mv = nodal cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is heart membrane potential affected by:

  • -Hypokalemia?
  • -Hyperkalemia?
A
  • -HypOkalemia –> hyperpolarizes, increases threshold (more current required)
  • -HypERkalemia –> depolarizes, decreases threshold (less current required)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is normal [K+] range?

A

3.5mM - 5.5mM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Do the following K+ concentrations Increase or decrease excitability?

  • -[K] less than 3.5
  • -[K] 5.5-7mM
  • -[K] over 7mM
A
  • -[K] less than 3.5 –> increase excitability (but, hyperpolarizes + increase threshold)
  • -[K] 5.5-7mM –> increase excitability (decrease threshold)
  • -[K] over 7mM –> decrease excitability (but, depolarizes + increase threshold b/c Na current inactivation)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What 3 things are different about an action potential elicited during the relative refractory period?

A
  • -Needs higher than normal stimulus
  • -Reduced amplitude
  • -Reduced duration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What current determines depolarization in:

  • -Myocardium?
  • -Nodes?
A
  • -Myocardium = I(Na) – sodium

- -Nodes = I(Ca, L-type) – calcium entering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

List the conduction velocities from slowest to fastest

  • -Atria
  • -AV node
  • -His - bundle branch (BB)
  • -Purkinje fibers
  • -Ventricles
A
  • -AV node –0.05m/s
  • -Atria –0.5m/s
  • -Ventricles –0.5m/s
  • -His-BB –2m/s
  • -Purkinje fibers –4m/s
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What channel do you block to prevent cardiac contraction

A

L type Ca+ channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What measurement is analogous to cardiac preload?

A

EDV –End diastolic volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What measurement is analogous to cardiac afterload?

A

TPR – Total peripheral (vascular) resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Sympathetic control of cardiac contractility is by what receptor? What G-coupling?

A

B1 adrenergic – Gs coupled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Parasympathetic control of cardiac contractility is by what receptor? What G-coupling?

A

M2 muscarinic – Gi coupled

21
Q

What kind of shift (left/right) of the slope on the Pressure/Volume loop graph indicates:

  • -Positive inotropy
  • -Negative inotropy
A
  • -left shift (increase slope) = positive inotropy

- -right shift (decrease slop) = negative inotropy

22
Q

What are the 2 causes of systolic dysfunction?

A
  • -Volume overload

- -Dilated cardiomyopathy

23
Q

What are the 3 causes of diastolic dysfunction?

A
  • -Pressure overload
  • -Hypertrophic cardiomyopathy
  • -Restrictive cardiomyopathy
24
Q

In ECG, what are the causes of:

  • -ST segment elevation?
  • -ST segment depression?
A
  • -ST elevation = transmural infarct, coronary vasospasm (Prinzmetal)
  • -ST depression = subendocardial ischemia, exertional (stable) angina
25
Q

What ECG finding in:

  • -Bigeminy?
  • -Trigeminy?
A
  • -Bigeminy = PVC after every sinus beat

- -Trigeminy = PVC after every 2 sinus beats

26
Q

What type of heart block?

  • -No P-R association
  • -Increasing PR interval w/ dropped beat
  • -Fixed PR interval w/ dropped beat
  • -Prolonged PR interval w/ 1:1 association
A
  • -No P-R association = 3rd Degree
  • -Increasing PR interval w/ dropped beat = 2nd Degree, Mobitz Type 1
  • -Fixed PR interval w/ dropped beat = 2nd Degree, Mobitz Type 2
  • -Prolonged PR interval w/ 1:1 association = 1st Degree
27
Q

What type of arrhythmia can be caused by hypothyroidism or sleep apnea?

A

Bradycardia

28
Q

What are the 2 most common SVTs (supraventricular tachycardias)

A
  • -AV node reentry – dual AV node conduction pathways (2/3 of SVTs)
  • -Bypass tract reentry – AV node and bypass tract reentry (1/5 of SVTs)
29
Q

Polymorphic, long QT syndrome that is either congenital (14 genes) or acquired (drug induced).
What is it?

A

Torsades de Pointes

30
Q

What is atrial rate and regularity in:

  • -Atrial Flutter
  • -Atrial Fibrillation
A
  • -Atrial flutter = 250-300b/m, regular, no ventricular transmission
  • -Atrial fibrillation =400-600b/m, irregular
31
Q

What arrhythmia rhythm is the leading cause of thrombotic stroke?

A

Atrial fibrillation

32
Q

On ECG, what kind of bundle branch block causes:

  • -Left axis deviation
  • -Right axis deviation
A
  • -Left axis deviation = left ANTERIOR fascicle

- -Right axis deviation = left POSTERIOR fascicle

33
Q

What is slow automatic ventricular rhythm w/ abnormal QRS caused by ectopic ventricular pacemaker origin?

A

Parasystole

34
Q

Fast AV accessory pathway starting in bundle of Kent
ECG: short PR interval, delta wave, wide QRS
What is it?

A

Wolf-Parkinson-White Syndrome – Atrioventricular Reciprocating Tachycardia

35
Q

Cinchonism is an adverse effect of what drug?

A

Quinidine – Class 1A antiarrhythmic

36
Q

What drug class prefers depolarized (ischemic tissue) Na channel blockade?

A

Class 1B antiarrhythmics – Lidocaine, mexiletine

37
Q

What antiarrhythmic drug is not used in the US anymore because of potential fatal bone marrow aplasia and pulmonary fibrosis?

A

Tocainide – Class 1B antiarrhytmic

38
Q

What antiarrhythmic class can cause heart block?

A

Class 1C

39
Q

The most common non-cardiac effect of this antiarrhytmic drug is blurred vision

A

Flecainide – Class 1C

40
Q

What antiarrhythmic class is contraindicated in WPW syndrome?

A

Class 2

41
Q

What is the primary drug o choice for sustained VT, VF and is useful against most all arrhythmias (except digitalis toxicity)?

A

Amiodarone – Class 3 (K channel block)

42
Q

What drug is a thyroxine analog that mimics all antiarrhythmic classes and has a half life of 80 days?

A

Amiodarone

43
Q

This drug a natural nucleoside,Gi-coupled, and has a half life of 10 seconds used to terminate PSVT

A

Adenosine

44
Q

Magnesium can be used to prevent what?

A

Recurrent Torsades de Pointes (TdP)

45
Q

Differentiate between Long QT Syndrome [1, 2, 3] by triggers:

  • -Sleep, auditory, post-partum
  • -Exercise, emotion
  • -Rest, sleep, bradycardia
A
  • -Sleep, auditory, post-partum = LQT2
  • -Exercise, emotion = LQT1
  • -Rest, sleep, bradycardia = LQT3
46
Q

Differentiate between Long QT Syndrome [1, 2, 3] by treatment:

  • -I(Na) “window” current block
  • -[K+] therapy
  • -B-Blockers
A
  • -I(Na) “window” current block = LQT3
  • -[K+] therapy = LQT2
  • -B-Blockers = LQT1
47
Q

Which Class 4 Antiarrhythmics are not effective at anti-arrhythmia, but useful in anti-anginal and anti-HTN? Why?

A

DHPs (dihydropyridines) – Nifedipine, Amlodipine, Felodipine, Isradipine

–Preferentially block vascular smooth muscle Ca channels

48
Q

What are 4 1st line drugs used for rate control in acute and chronic A-fib or A-flutter?

A
  • -Verapamil
  • -Diltiazem
  • -B-blocker
  • -Digoxin
49
Q

This antiarrhythmic drug is:

  • -Na/K pump inhibitor
  • -Has vagotonic effect
  • -Has low theraputic index
  • -Can cause blurred or yellow vision
  • -Is a positive inotropic agent for heart failure
  • -Is a cardiac glycoside
A

Digoxin