Arrhythmias

Question 1

• **• Bradycardias

* **• Tachycardias

Answer 1

(Bradyarrhythmias)

Tachyarrhythmias

Question 2

Supraventricular

Answer 2

when involving atrium or AV

Question 3

Ventricular

Answer 3

Originate HIS-PURKINJE

Question 4

**Mechanisms of arrythmias

Answer 4

• Altered impulse formation
• Altered impulse conduction
• BOTH

Question 5

*** Fastest cells preempt all others

Answer 5

= “Overdrive Suppression

Question 6

*****Normally____ node dominates _____
AV and Bundle of HIs ________
Purkinje

Answer 6

SA ; 60-100
50-60
30-40

Question 7

***3 causes of altered impulse formation

Answer 7

3 Causes:
• Altered SA rate
• Abnormal automaticity in myocytes
• Triggered activity

Question 8

**Triggered Activity

Answer 8

Abnormal oscillations in membrane voltage

can develop during or after repolarization “afterdepolarizations”

Question 9

*****TRIGGERED ACTIVITY• Once triggered, they can become

Answer 9

selfsustaining tachycardias.

Question 10

**Triggered activity EARLY (LPDT)

Occur when?

Answer 10

can occur in LONG depolarization
• ex. Conditions that cause PROLONGED QT
• (slowing can cause reversal of ion mvmt.)
• Depolarization initiates tachycardia
TORSADES DE POINTES

Question 11

**Triggered activity DELAYED (DAD)

Answer 11

occur after REPOLARIZATION
**Due to ↑ Ca++ in cell SECONDARY to digitalis intoxication or ↑ catecholamines
• Activates Cl- out channels or Na -Ca exchanger (Na+ in Ca++ out)
• Depolarizes membrane, triggers *V-Tach.

Question 12

*****Altered Impulse Conduction

Answer 12

• Normal conduction pathway does not have blocks

or reentry pathways

Question 13

***Blocks =

Answer 13

bradycardias

Question 14

***** Reentry pathways =

Answer 14

tachycardias

Question 15

***3 types of Tachycardias

Answer 15

Supraventricular
Ventricular
Ventricular Pre-excitation Syndrome

Question 16

*****Supraventricular tachycardias are

Answer 16

Sinus Tachycardia
– PACs
– SVT
– Multifocal Atrial Tachycardia
A-flutter
– A-fib

Question 17

*****Ventricular Tachycardias are

Answer 17

– PVCs
– V-tach
– V-fib

Question 18

*****Ventricular Pre-excitation Syndrome

Answer 18

– WPW

Question 19

PACs

• Arise from_______
• Felt as _____

Answer 19

Arise from ectopic foci in atria

• Felt as “fluttering” or a “heavy” heartbeat

Question 20

SA node rate

Answer 20

60-`100

Question 21

AV node rate

Answer 21

50-60

Question 22

Purkinje fibers

Answer 22

30-40

Question 23

Anesthesia consideration for tachycardia

Answer 23

Avoidance of vagolytic drugs intraoperatively

ex. Pancuronium

Question 24

PACs anesthesia consideration

Answer 24

Avoid excessive sympathetic stimulation
• Treatment only required if they trigger secondary
dysrhythmias

Question 25

SVT rate Initiated where? In EKG, p waves are

Answer 25

140-250 bpm at or above AV node -buried in QRS

Question 26

What is the goal of therapy for a patient with Atrial flutter? what are we avoiding?

Answer 26

Ventricular rate control is initial goal of therapy to avoid 1:1 AV conduction

Question 27

• If 1:1 conduction occurs with ventricular rate ≥ 300, is _______most likely mechanism - - consider

Answer 27

reentry; procainamide (Class IA)

Question 28

Most important clinical consequence of AF is

Answer 28

thromboembolic event causing stroke

Question 29

When 3 or more consecutive PVCs occur

Answer 29

Vtach

Question 30

Torsades de Pointes -

Answer 30

“twisting of the points” | • A.k.a. Polymorphic VT

Question 31

Tx of torsade

Answer 31

Magnesium

Question 32

Vfib

Answer 32

Cessation of C.O. & Death without prompt | treatment

Question 33

Survival is highest if defibrillation occurs in

Answer 33

3 to 5 minutes of cardiac arrest

Question 34

_____ _______ is only effective treatment

Answer 34

Electrical defibrillation

Question 35

After 3 attempts with epi or vaso, administration of.

Answer 35

amiodarone, lidocaine (or Mg for TdP) is indicated

Question 36

WPW (On left side of heart =

Answer 36

Type A, on right = Type B)

Question 37

For Orthodromic (narrow QRS) : –

Answer 37

begin with vagal maneuvers, if unsuccessful, consider | adenosine, verapamil, beta-blockers or amiodarone.

Question 38

For Antidromic (wide QRS): –

Answer 38

Treatment is intended to block the accessory pathway – The above drugs may worsen condition – Use procainamide 10 mg/kg IV infused up to 50mg/min. – (procainamide slows accessory pathway)

Question 39

Bradycardia

Answer 39

``` Sinus Bradycardia Escape Rhythms First degree AV Block 2nd degree AV Block Thrid Degree AV Block ``` Atropine 0.5 mg IV q 3-5 min. (to a max of 3 mg) – Note: doses < 0.5 mg can cause further slowing of HR

Question 40

Bradycardia Can occur with or without sedation. | • Can occur any time during neuraxial blockade, but

Answer 40

1 hour after anesthetic is | initiated.

Question 41

• Warning Signs prior to arrest for Bradycardia:

Answer 41

SOB, nausea, restlessness, light-headedness, tingling fingers, deterioration in mental status

Question 42

First Degree AV Block | •

Answer 42

Prolonged PR interval (> 5 small boxes)

Question 43

1st degree AVB tx

Answer 43

Check Digoxin levels prior to surgery | • Maintain serum K+ levels in pts. on Digoxin

Question 44

Second Degree AV Block • Mobitz Type I – Wenckebach •

Answer 44

Caused by intermittent failure of AV conduction | • Progressive prolongation of PR until a QRS is dropped

Question 45

Mobitz Type II – Sudden

Answer 45

QRS drop, more dangerous

Question 46

Type I Vs Type more dangerous type is

Answer 46

Type II

Question 47

Does atropine work in type II AVB

Answer 47

no

Question 48

Tx of type I is only for symptomatic patient, but treatment of Type II AVB

Answer 48

``` Cardiac Pacing (transcutaneous or transvenous) • Atropine does not work • Pacemaker warranted, even if pt. is asymptomatic ```

Question 49

This block most common with Acute MI

Answer 49

3rd degree AVB

Question 50

3rd AVB there is dissociation of the __________.

Answer 50

atria and ventricles

Question 51

Medication that can be used as a chemical pacemaker until pacemaker becomes functional?

Answer 51

Isoproterenol