Arrythymia 2

Question 1

Two arrythymia starts

Answer 1

Impulse Generation and Impulse Conduction

Question 2

Impulse generation refers to….

Answer 2

Automaticity- spontaneous impulse generation in latent pacemaker cells

Question 3

Impulse conduction refers to…

Answer 3

Re-entrant arrhythmias- indefinite propagation of the impulse and continued activation of previously refractory cells

Question 4

Examples of AUtomaticity Arrythymias

Answer 4

sinus tachycardia – Cells other than the SA node depolarize faster than the SA nodal cells and take control as the pacemaker

multifocal atrial tachycardia –> Transient membrane depolarizations that occur during repolarization (relative refractory period)

Question 5

Conduction requirementsfor re-entry arrythymia

Answer 5

Two pathways for impulse conduction

An area of unidirectional block (prolonged refractoriness)

Slow conduction in the other pathway

Question 6

Antiarrthymic Meds

Answer 6

Class 1 all works all Na+ channels
2 –> beta blockers
3 –> K+ channels (Amiodarone does them all)
4 –> Ca2+ channels

Question 7

Class I

Answer 7

A –> Lowers automaticity

B –> Lidocaine –> Shortens repo;arization

C - Depolarization occurs for longer

Question 8

Class III

Answer 8

Block potassium channels thereby prolonging the refractory period

Question 9

CCB

Answer 9

Slow conduction, prolong refractoriness, and decrease automaticity of calcium dependent cells in the SA and AV nodes

Question 10

Digoxin

Answer 10

Inhibitor of Na+/K+ -ATPase

Increases vagal tone, which reduces conduction velocity (decrease the herat rate)

Increases AV node refractoriness

Question 11

Bradycardia Definition

Answer 11

Heart Rate Less Than 60 bpm

Question 12

Bradycardia sx occur when? What are they?

Answer 12

Usually, patients won’t have symptoms unless heart rate is dropping below 50 bpm

Symptoms can include fatigue, lightheadedness, palpitations, or syncope (pass out)

Question 13

What is AV block?

Answer 13

Conduction delay or “block” in an area of the AV conduction system

Not beta blocker

Question 14

Degrees of AV block

Answer 14

First degree (least severe- prolonged PR interval)
Second degree
Third degree (most severe- absence of AV conduction)

Question 15

Tx Brady

Answer 15

Treatment for chronic symptomatic AV block is a pacemaker

Question 16

Sick Sinus SYndrome

Answer 16

Pauses or dropped beats due to SA node dysfunction
Usually caused by degenerative changes due to age
Leave it alone, unless symptomatic, then pacemaker

Question 17

Tachycardia

Answer 17

Heart Rate Greater Than 100 bpm

Question 18

Supraventricular Tachycardia Cause

Answer 18

Usually caused by re-entry mechanisms

Question 19

SVT Sx

Answer 19

palpitations, fatigue, lightheadedness, neck fullness, chest pain (blood not getting where it needs to do)

Question 20

SVT tx

Answer 20

For narrow QRS complex: first line treatment is vagal maneuvers

Second line is adenosine, or IV beta-blocker or calcium channel blocker if needed

Question 21

Type sof ventricular tacyyartythmia

Answer 21

Premature Ventricular Complexes (PVCs)
Benign, common (structuaral heart dx (recent MI’s))

Ventricular tachycardia (VT)
Potentially fatal, life threatening
Eventually leads to V-fib  No blood circulated to the body

Ventricular fibrillation (VF)
Fatal, medical emergency

Question 22

PVC’s tx

Answer 22

Often asymptomatic, can occur in healthy individuals

Usually don’t require any treatment

Question 23

VT TX

Answer 23

Sustained VT, unstable patient: First line is direct current (DC) cardioversion

Stable patient: medication can be used, IV procainamide, amiodarone, lidocaine

Question 24

Maintainenece tx VT

Answer 24

Once acute VT terminated, possibility of recurrence

Amiodarone is most effective as maintenance therapy to prevent VT recurrence

Sotalol also option for maintenance therapy

Ablation can be considered if medication therapy fails

Question 25

VF TX

Answer 25

More common in people with acute MI, drug overdose, hypoxemia (not perfusing the tissues)

Terminal event unless corrected  Not perfusing

DC cardioversion first line, IV amiodarone if unsuccessful

Question 26

Torsade Des Pointes

Answer 26

Life threatening form of VT

Associated with long QT interval on ECG

Treatment: Magnesium sulfate 2g IV (stabilize cardiac membrane), DC cardioversion

Outcome of QT prolongation

Question 27

Amiodarone???

Answer 27

• Does not affect renal system

ALOT of SIDE effects

Qt prolong, phosens, hyperthyroid, blue-grey skin, Liver enzyme increase, vision changes, pulmonary toxicity, cough, fveer, dyspnea

Question 28

QT risk? Higher when? Why?

Answer 28

Risk higher with antiarrythmic medications due to their potassium channel blocking properties
Sotalol risk of TdP around 4%

Question 29

QTc prolongation? Definition?

Answer 29

Females- greater than 480 msec

Males- greater than 470 msec

Need to become worried if QTc exceeding 500 msec

Question 30

Tisadle Score

Answer 30