Clinical Treatment of Arrhythmias

Question 1

Slow arrhythmia

Answer 1

brady arrhythmias

Question 2

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

Answer 2

• sinus node
• AV node
• below the av node

Question 3

Sinus node dysfunctions

Answer 3

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

Question 4

Sinus Arrest

Answer 4

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

Question 5

Bradycardia-Tachycardia (Brady-Tachy) Syndrome

Answer 5

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

Question 6

AV node dysfunctions

Answer 6

• first degree AV block

- Mobitz I 2nd degree AV block (Wenkebach)

Question 7

1st degree AV block

Answer 7

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).

Question 8

Second-Degree AV Block – Mobitz I (Wenckebach)

Answer 8

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

Question 9

below the AV node dysfunctions

Answer 9

• Mobitz II 2nd degree AV block

- complete heart block

Question 10

Second-Degree AV Block – Mobitz II

Answer 10

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

Question 11

Third-Degree AV Block

Answer 11

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

Question 12

When should you be concerned about a bradyarrhythmia pt?

Answer 12

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).

Question 13

Treatment of bradyarrhythmia?

Answer 13

• 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

Question 14

Types/origins of tachyarrhythmias

Answer 14

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

Question 15

Acute treatment of irregular SVT

Answer 15

If unstable: shock

Stable: can control their rates, use antiarrhythmics, or cardioversion

Question 16

5 C’s of A. Fib management

Answer 16

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

Question 17

Common causes of A. Fib

Answer 17

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

Question 18

Immediate Tx of A Fib

Answer 18

Cardiovert

Control the Rate

Question 19

Pharmacological rhythm control in A fib

Answer 19

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

Question 20

Electrical rhythm control in A Fib

Answer 20

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

Question 21

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

Answer 21

True, especially if they are symptomatic in AF.

Question 22

When are Class IC agents contraindicated?

Answer 22

in CAD and structural heart disease

Question 23

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

Answer 23

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

Question 24

T or F: Digoxin controls rate during exercise well

Answer 24

False

Question 25

Rate control medications

Answer 25

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

Question 26

Which medications control HR during exercise?

Answer 26

Betablockers and rate limiting Ca Antagonists

Question 27

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

Answer 27

True

Question 28

Tx strategies for atrial flutter

Answer 28

- 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

Question 29

List other SVT categories

Answer 29

- 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”.

Question 30

Tx options for other SVTs

Answer 30

- 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

Question 31

What are the 2 types of arrhythmias?

Answer 31

Tachy- and bradyarrhythmia

Question 32

What is chronotropic incompetence

Answer 32

inability to mount age-appropriate HR with exercise

Question 33

An SVT can be subdivided into those that are _________________.

Answer 33

irregular and those that are regular.

Question 34

Irregular SVT can be broken down into what 3 types?

Answer 34

-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

Question 35

Regular SVTs have what P to QRS ratio?

Answer 35

1:1, (sometimes can’t see p waves)

Question 36

Acute treatment of regular SVT

Answer 36

adenosine

Question 37

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

Answer 37

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

Question 38

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

Answer 38

True

Question 39

What is the most common SVT?

Answer 39

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

Question 40

What is the least common SVT?

Answer 40

Focal atrial tachycardias

Question 41

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

Answer 41

Ventricular tachyarrhythmia

Question 42

What is the acute Tx approach for stable ventricular Tachyarrhythmias?

Answer 42

``` -Medications: Amiodarone Lidocaine Procainamide -Treat underlying causes ```

Question 43

What is the acute Tx approach for UNstable ventricular Tachyarrhythmias?

Answer 43

- SHOCK - Treat underlying causes - Medications

Question 44

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

Answer 44

True

Question 45

First line of therapy for ventricular tachyarrhythmias?

Answer 45

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

Question 46

When is a defibrillator needed for VTs?

Answer 46

- 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.

Question 47

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

Answer 47

ICD leads have coils

Question 48

Sudden Cardiac Death (SCD) prognosis

Answer 48

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

Question 49

The go to treatment for Any unstable tachyarrhythmia

Answer 49

SHOCK

Question 50

How can adenosine help dx SVT?

Answer 50

helps you see the P wave