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MQW U4 > Pharm --Heart Phys/Antiarrhythmic > Flashcards

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

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2
Q

This class of antiarrhythmics work on voltage gated K channels

A

Class 3 – K channel blockers

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3
Q

This class of antiarrhythmics work on voltage gated Ca channels

A

Class 4 – Ca channel blockers

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4
Q

This class of antiarrhythmics work on sympathetic innervation?

A

Class 2 – B-blockers

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5
Q

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

A

Class 1A

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6
Q

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

A

Class 1B

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7
Q

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

A

Myocardium: Atrium, Ventricle, His-Purkinje

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8
Q

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

A

SA node, AV node

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9
Q

What heart cells have excitation threshold around:

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

- -35mv = nodal cells

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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)
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11
Q

What is normal [K+] range?

A

3.5mM - 5.5mM

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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)
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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
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14
Q

What current determines depolarization in:

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

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

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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
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16
Q

What channel do you block to prevent cardiac contraction

A

L type Ca+ channel

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17
Q

What measurement is analogous to cardiac preload?

A

EDV –End diastolic volume

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18
Q

What measurement is analogous to cardiac afterload?

A

TPR – Total peripheral (vascular) resistance

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19
Q

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

A

B1 adrenergic – Gs coupled

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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
What ECG finding in: - -Bigeminy? - -Trigeminy?
- -Bigeminy = PVC after every sinus beat | - -Trigeminy = PVC after every 2 sinus beats
26
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
- -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
What type of arrhythmia can be caused by hypothyroidism or sleep apnea?
Bradycardia
28
What are the 2 most common SVTs (supraventricular tachycardias)
- -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
Polymorphic, long QT syndrome that is either congenital (14 genes) or acquired (drug induced). What is it?
Torsades de Pointes
30
What is atrial rate and regularity in: - -Atrial Flutter - -Atrial Fibrillation
- -Atrial flutter = 250-300b/m, regular, no ventricular transmission - -Atrial fibrillation =400-600b/m, irregular
31
What arrhythmia rhythm is the leading cause of thrombotic stroke?
Atrial fibrillation
32
On ECG, what kind of bundle branch block causes: - -Left axis deviation - -Right axis deviation
- -Left axis deviation = left ANTERIOR fascicle | - -Right axis deviation = left POSTERIOR fascicle
33
What is slow automatic ventricular rhythm w/ abnormal QRS caused by ectopic ventricular pacemaker origin?
Parasystole
34
Fast AV accessory pathway starting in bundle of Kent ECG: short PR interval, delta wave, wide QRS What is it?
Wolf-Parkinson-White Syndrome -- Atrioventricular Reciprocating Tachycardia
35
Cinchonism is an adverse effect of what drug?
Quinidine -- Class 1A antiarrhythmic
36
What drug class prefers depolarized (ischemic tissue) Na channel blockade?
Class 1B antiarrhythmics -- Lidocaine, mexiletine
37
What antiarrhythmic drug is not used in the US anymore because of potential fatal bone marrow aplasia and pulmonary fibrosis?
Tocainide -- Class 1B antiarrhytmic
38
What antiarrhythmic class can cause heart block?
Class 1C
39
The most common non-cardiac effect of this antiarrhytmic drug is blurred vision
Flecainide -- Class 1C
40
What antiarrhythmic class is contraindicated in WPW syndrome?
Class 2
41
What is the primary drug o choice for sustained VT, VF and is useful against most all arrhythmias (except digitalis toxicity)?
Amiodarone -- Class 3 (K channel block)
42
What drug is a thyroxine analog that mimics all antiarrhythmic classes and has a half life of 80 days?
Amiodarone
43
This drug a natural nucleoside,Gi-coupled, and has a half life of 10 seconds used to terminate PSVT
Adenosine
44
Magnesium can be used to prevent what?
Recurrent Torsades de Pointes (TdP)
45
Differentiate between Long QT Syndrome [1, 2, 3] by triggers: - -Sleep, auditory, post-partum - -Exercise, emotion - -Rest, sleep, bradycardia
- -Sleep, auditory, post-partum = LQT2 - -Exercise, emotion = LQT1 - -Rest, sleep, bradycardia = LQT3
46
Differentiate between Long QT Syndrome [1, 2, 3] by treatment: - -I(Na) "window" current block - -[K+] therapy - -B-Blockers
- -I(Na) "window" current block = LQT3 - -[K+] therapy = LQT2 - -B-Blockers = LQT1
47
Which Class 4 Antiarrhythmics are not effective at anti-arrhythmia, but useful in anti-anginal and anti-HTN? Why?
DHPs (dihydropyridines) -- Nifedipine, Amlodipine, Felodipine, Isradipine --Preferentially block vascular smooth muscle Ca channels
48
What are 4 1st line drugs used for rate control in acute and chronic A-fib or A-flutter?
- -Verapamil - -Diltiazem - -B-blocker - -Digoxin
49
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
Digoxin

MQW U4 (9 decks)

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