Pharmacology - Chapter 48 - Antidysrhythmic Drugs

Question 1

Dysrhythmia - def

Answer 1

abnormality in rhythm of the heartbeat.

Question 2

In mildest forms of dysrhythmia, there are only ___ effects on cardiac output.
In severe forms, they can ___ the heart so that ___ cardiac output occurs.

Answer 2

Mild effects.
Disable.
No.

Question 3

What are the 2 types of dysrhythmias?

Answer 3

Tachydysrhythmias and Bradydysrhythmias.

Question 4

Drugs that treat dysthythmias can cause them. T/F?

Answer 4

True!

Question 5

In healthy heart - impulse originates at ___ node, spreads rapidly through ____, passes slowly through __ node, spreads rapidly through the ___ via the ____ ___ ___.

Answer 5

SA Node
Atria.
AV node.
ventricle via the His-Purkinje System.

Question 6

EKG - P wave =

Answer 6

depolarization in atria (atrial contraction.)

Question 7

QRS Wave =

Answer 7

depolarization of ventricles (ventricular contraction.)

Question 8

T-wave =

Answer 8

repolarization of ventricles (not associated with physical activity of heart.)

Question 9

PR wave - represents the time between…

Answer 9

onset of the P wave and onset of the QRS complex.

Question 10

Prolongation of the PR wave indicates….

Answer 10

delayed AV conduction.

Question 11

QT Wave - the time between onset of the ….. and the completion of the….

Answer 11

QRS complex and completion of the T Wave.

Question 12

QT prolongation indicates….

Answer 12

delayed ventricular repolarization.

Question 13

What are the two types of disturbances that can generate dysrhythmias?

Answer 13

Disturbances of impulse formation (automaticity)(Sa or AV nodes) and Disturbances of conduction (like an AV block.)

Question 14

What are the two major groups of Dysrhythmias?

Answer 14

Supraventricular and Ventricular!

Question 15

Supraventricular Dysrhythmias - where do they come from? And what are some?

Answer 15

Impulses arise above the ventricule, like SVT (Supraventricular Tachycardia), Atrial flutter, A Fib, etc.

Question 16

Ventricular Dysrhythmias - they are less dangerous than Supraventricular Dysrhytmia - T/F?

Answer 16

False! They are more dangerous!

Question 17

What are some ventricular Dysrhythmias?

Answer 17

Ventricular Tachycardia, Ventricular Fibrilation, and Ventricular Premature Beats (VPB)

Question 18

What are the Vaughan Williams Classifications?

Answer 18

Class 1-4.
Class 1 - blocks sodium channels and delays ventricular repolarization (Quinidine.)
Class 2 - beta blockers (Propanalol.)
Class 3 - potassium channel blockers, delay repolarization (Bretylium.)
Class 4- calcium channel blockers; reduces SA node activity (Cardizem.)
Others - Digoxin.

Question 19

Class 1A Agents - What is the drug?

Answer 19

Quinidine - Cinchona alkaloid, blocks sodium channels,delays repolarization.

Question 20

What are the adverse effects of Quinidine?

Answer 20

Diarrhea, Cinchonism, Cardiotoxicity.

Question 21

Class 1 B Agents - Drug

Answer 21

Lidocaine (Xylocaine) - Blocks sodium channels, reduces automaticity in ventricles, accelerates repolarization.

Question 22

What are the adverse effects of Lidocaine?

Answer 22

CNS effects, confusion, paresthesias (Paresthesia is a sensation of tingling, tickling, prickling, pricking, or burning of a person’s skin with no apparent long-term physical effect.)

Question 23

Class 2 Beta Blockers - What is the drug?

Answer 23

Propanalol - a nonselective beta adrenergic. It is used for tachydysrhythmias.

Question 24

What are the adverse effects of propranolol?

Answer 24

Bronchospasm, heart failure, av block, and sinus arrest.

Question 25

Class 3 Potassium Channel Blockers - what is the drug?

Answer 25

Bretylium. It delays repolarization of fast potentials. The QT interval is prolonged. It is used for Ventricular Tachycardia and V Fib.

Question 26

What is the adverse effect of Bretylium?

Answer 26

Profound hypertension.

Question 27

Class 4 Calcium Channel Blockers - Drug/what does it do, etc.

Answer 27

Verapamil - Reduces SA nodal automaticity, delays av nodal conduction, reduces myocardial contractility…it is used for SVT Atrial flutter, atrial fibrilation…

Question 28

What are the adverse effects of Verapamil -

Answer 28

Bradycardia, AV block, Heart failure.