Clinical Treatment of Arrhythmias Flashcards Preview

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Flashcards in Clinical Treatment of Arrhythmias Deck (50):
1

Slow arrhythmia

brady arrhythmias

2

If the rhythm is too slow, where in the conduction system is it affected?

-sinus node
-AV node
-below the av node

3

Sinus node dysfunctions

-Sinus bradycardia
-sinus arrest/pause
-tachy-brady syndrome
-chronotropic incompetence

4

Sinus Arrest

Failure of sinus node discharge resulting in the absence of atrial depolarization and periods of ventricular asystole

5

Bradycardia-Tachycardia (Brady-Tachy) Syndrome

Intermittent episodes of slow and fast rates from the SA node or atria

6

AV node dysfunctions

- first degree AV block
- Mobitz I 2nd degree AV block (Wenkebach)

7

1st degree AV block

AV conduction is delayed, and the PR interval is prolonged (> 200 ms or .2 seconds). each atrial signal is conducted to the ventricles (1:1 ratio).

8

Second-Degree AV Block – Mobitz I (Wenckebach)

Progressive prolongation of the PR interval until a ventricular beat is dropped
-Ventricular rate: irregular

9

below the AV node dysfunctions

- Mobitz II 2nd degree AV block
- complete heart block

10

Second-Degree AV Block – Mobitz II

-Intermittently dropped ventricular beats preceded by constant PR intervals
-The infranodal (His bundle) tissue is most commonly the site of Mobitz II block.

11

Third-Degree AV Block

-No impulse conduction from the atria to the ventricles
-PR interval = variable
-also referred to as complete heart block

12

When should you be concerned about a bradyarrhythmia pt?

1. When the patient is symptomatic, no matter which part of the conduction system is affected.
2. When the rhythm is infranodal (below the AV node).

13

Treatment of bradyarrhythmia?

-Find and treat reversible causes– ischemia/infarction, hypothyroidism, neurologic causes, Lyme disease
-Stop offending medications, if possible: antiarrhythmics, clonidine, lithium, among others.
-Acute treatment for unstable patient: beta-agonists (dopamine or isoproterenol), transcutaneous pacing, temporary transvenous pacing.
-Long term: Permanent pacemaker

14

Types/origins of tachyarrhythmias

Above ventricle:
-Supraventricular Tachycardias (SVT)
Ventricles:
-Ventricular Tachycardia
-Ventricular Fibrillation

15

Acute treatment of irregular SVT

If unstable: shock
Stable: can control their rates, use antiarrhythmics, or cardioversion

16

5 C's of A. Fib management

Cause: Reverse
Control Rate
antiCoagulation (I know, no C there)
Control Rhythm
Cure: Ablation

17

Common causes of A. Fib

Hypertension 14%
IHD
Mitral valve Disease
Alcohol
Cardiomyopathies
Hyperthyroidism
Lone AF 14%

18

Immediate Tx of A Fib

Cardiovert
Control the Rate

19

Pharmacological rhythm control in A fib

Less successful
Does not require sedation
Class III agents- ibutilide, amiodarone, dofetilide, sotalol
Class IC agents- flecainide, propafenone

20

Electrical rhythm control in A Fib

DC Shock 70-90% success
Day procedure in hospital
Needs sedation

21

T or F: Patients with recurrent AF may require long term maintenance medications to control rhythm

True, especially if they are symptomatic in AF.

22

When are Class IC agents contraindicated?

in CAD and structural heart disease

23

Should Patients with a rhythm control agent should still be anticoagulated?

Yes, risk still present for thromboembolism, as rhythm control is not a cure.

24

T or F: Digoxin controls rate during exercise well

False

25

Rate control medications

Betablockers
Digoxin
Verapamil
Diltiazem
Amiodarone: can be used as a rate-controlling agent, especially in setting of decompensated heart failure.

26

Which medications control HR during exercise?

Betablockers and rate limiting Ca Antagonists

27

T or F: Use of medications in combination can develop heart block

True

28

Tx strategies for atrial flutter

-Similar to A Fib
-Catheter ablation more successful than medications, 95% cure rate
-with successful catheter ablation, anticoagulation no longer necessary
-Lower ablation risk when compared to A fib

29

List other SVT categories

-AV nodal reentrant tachycardia (circuit within the AV node): most common, accounts for ~65% of regular SVTs (not including AF/flutters).
-Accessory pathway-mediated tachycardias: abnormal connection between atrium and ventricle.
-Focal atrial tachycardias: least common, abnormal focus of atrial tissue with enhanced automaticity– a “hotspot”.

30

Tx options for other SVTs

-Nonpharmacologic maneuvers: vagal maneuvers.
-Pill in pocket: Medication only with symptoms.
-Long term: beta blockers, calcium channel blockers to block AV node, Class I antiarrhythmics to suppress hotspots or premature beats that are triggers for tachycardia.
-Ablation

31

What are the 2 types of arrhythmias?

Tachy- and bradyarrhythmia

32

What is chronotropic incompetence

inability to mount age-appropriate HR with exercise

33

An SVT can be subdivided into those that are _________________.

irregular and those that are regular.

34

Irregular SVT can be broken down into what 3 types?

-atrial fibrillation, where there are no discrete P waves
-multifocal atrial tachycardia, where there are 3 or more p waves
-atrial flutter with variable conduction and one would see flutter waves

35

Regular SVTs have what P to QRS ratio?

1:1, (sometimes can’t see p waves)

36

Acute treatment of regular SVT

adenosine

37

T or F: Cardioversion can be achieved either with drugs or electricity

True, Drugs are less successful but do not require sedation.

38

T or F: atrial flutter Can be more difficult to rate or rhythm control than AF

True

39

What is the most common SVT?

AV nodal reentrant tachycardia, circuit w/in the AV node

40

What is the least common SVT?

Focal atrial tachycardias

41

If pt has coronary artery disease, 90% of the time the wide complex tachycardia is _______

Ventricular tachyarrhythmia

42

What is the acute Tx approach for stable ventricular Tachyarrhythmias?

-Medications:
Amiodarone
Lidocaine
Procainamide
-Treat underlying causes

43

What is the acute Tx approach for UNstable ventricular Tachyarrhythmias?

-SHOCK
-Treat underlying causes
-Medications

44

T or F: If there is structural heart disease with the ventricular arrhythmia, then they most likely will require a defibrillator.

True

45

First line of therapy for ventricular tachyarrhythmias?

Ablation and medications are first line therapy, ICDs are sometimes contraindicated

46

When is a defibrillator needed for VTs?

-Secondary prevention: When the patient has had a sudden cardiac arrest due to VT or VF without a reversible cause (ischemia, drugs, electrolytes).
-Primary prevention: When the patient has not had a cardiac arrest but is at significant risk.

47

What is the difference b/t the leads of a pacemaker and an ICD?

ICD leads have coils

48

Sudden Cardiac Death (SCD) prognosis

Only one-third of SCD cases are resuscitated and 10% survive to leave the hospital, many with morbidities

49

The go to treatment for Any unstable tachyarrhythmia

SHOCK

50

How can adenosine help dx SVT?

helps you see the P wave