CV - clinical treatment of arrhythmias

Question 1

impulse formation starts at the ____________ node.

Answer 1

sinoatrial (SA)

Question 2

the ____________ system is the most proximal branch of the bundle branch system.

Answer 2

his-purkinje

Question 3

arrhythmias that are too slow are called ____________.

Answer 3

bradyarrhythmias

Question 4

where in the conduction system can bradyarrhythmias occur?

Answer 4

sinus node
atrioventricular node
below the AV node

Question 5

define sinus bradycardia

Answer 5

persistent slow rate from SA node
rate of 55 bpm
PR interval 180 ms (0.18 s)

Question 6

define sinus arrest

Answer 6

failure of sinus node to discharge resulting in the absence of atrial depolarization and periods of ventricular asystole
rate of 75 bpm
PR interval 180 ms (0.18 seconds)

Question 7

what are examples of bradyarrhythmias at the level of the AV node?

Answer 7

1st degree AV block

2nd degree AV block type 1 (mobitz 1, wenckebach)

Question 8

describe 2nd degree AV block type 1 (mobitz 1, wenckebache)

Answer 8

progressive prolongation of the PR interval until a ventricular beat is dropped

ventricular rate irregular
atrial rate 90 bpm
PR interval is progressively longer until a P wave fails to conduct

Question 9

when should you be concerned about bradycardia?

Answer 9

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 10

what are the reversible causes of bradycardia?

Answer 10

ischemia/infarction
hypothyroidism
neurologic causes
lyme disease

Question 11

what are the acute treatments for unstable patients?

Answer 11

beta agonists (IV dopamine or IV isoproterenol)
transcutaneous pacing
temporary transvenous pacing

Question 12

what are the long term treatments for unstable patients?

Answer 12

permanent pacemaker

Question 13

what are the steps to approach a patient presenting with bradycardia?

Answer 13

determine level of block responsible for bradycardia
symptoms dictate treatment
treat reversible causes
acutely stabilize patients
long-term treatment - permanent pacemaker

Question 14

tachyarrhythmias can originate ____________ or ____________.

Answer 14

above the ventricle

in the ventricle

Question 15

it is unlikely that a ventricular tachyarrhythmia has a ____________ QRS.

Answer 15

narrow

Question 16

tachyarrhythmias originating SVT present with a ____________ QRS on ECG.

Answer 16

narrow

Question 17

if the QRS on ECG is narrow, the tachyarrhythmia must be an ____________.

Answer 17

SVT

Question 18

what are the three possible causes of an SVT with an irregular rhythm?

Answer 18

atrial fibrillation
multifocal atrial tachycardia (MAT)
atrial flutter

Question 19

typical atrial flutter courses around the ____________ valve.

Answer 19

tricuspid

Question 20

what are the six potential causes of an SVT with a regular rhythm?

Answer 20

sinus tachycardia 
atrioventricular nodal reentrant tachycardia atrioventricular reentrant tachycardia
atrial flutter
atrial tachycardia
junctional tachycardia

Question 21

if a patient presents with a tachycardia and is hemodynamically UNSTABLE, the treatment is ____________.

Answer 21

shock - cardioversion or defibrillation

Question 22

what are the treatment for SVTs with irregular rhythms?

Answer 22

rate control
antiarrhythmics
cardioversion

Question 23

IV ____________ is the treatment for regular 1:1 SVTs.

Answer 23

adenosine

Question 24

what is an alternative treatment to adenosine?

Answer 24

vagal maneuver

Question 25

describe an atrioventricular nodal reentrant tachycardia

Answer 25

reentrant circuit within the AV node fast and slow pathways atria and ventricles depolarized simultaneously P wave buried within or on the tail end of the QRS complex regular, narrow complex tachycardia P waves not visible

Question 26

what is Wolff-Parkinson-White syndrome?

Answer 26

patient is born with an accessory electrical pathway between atria and ventricles if accessory pathway is able to propagate in the forward direction, ventricle is depolarized prematurely - pre excitation of a ventricle presents as delta wave ("slurred upslope") on ECG setup for AVRT

Question 27

if an accessory pathway is functional, ____________ is likely to develop.

Answer 27

AVRT (atrioventricular reentrant tachycardia)

Question 28

if there is no gateway to slow the conduction of signals from the atria to the ventricles as in WPW syndrome, atrial fibrillation may become ____________ and may lead to ____________.

Answer 28

ventricular fibrillation | sudden cardiac death

Question 29

what are the three main categories of SVTs?

Answer 29

AV nodal reentrant tachycardia accessory pathway-mediated tachycardias focal atrial tachycardias

Question 30

what is the most common of the SVTs?

Answer 30

AV nodal reentrant tachycardia

Question 31

what are the long-term medications used to treat SVTs?

Answer 31

``` beta blockers calcium channel blockers to block AV node class I anti arrhythmics to suppress hotspots or premature beats that may trigger tachycardia ```

Question 32

what are the common causes of atrial fibrillation?

Answer 32

``` hypertension mitral valve disease alcohol ("holiday heart") cardiomyopathies hyperthyroidism lone atrial fibrillation ```

Question 33

there is an increased risk of ____________ in patients with atrial fibrillation.

Answer 33

thrombus formation | embolic stroke

Question 34

in patients with atrial fibrillation, thrombus formation most commonly occurs in the ____________.

Answer 34

left atrial appendage

Question 35

the acute treatment of ventricular tachyarrhythmias are determined by whether the patient is ____________ or ____________.

Answer 35

stable | unstable

Question 36

if a patient presents with ventricular tachyarrhythmia and is unstable, the treatment is ____________.

Answer 36

shock

Question 37

after shock, what are the treatments for unstable ventricular tachyarrhythmias?

Answer 37

treat underlying causes | medications

Question 38

what are the treatments for stable patients presenting with ventricular tachyarrhythmias?

Answer 38

medications (amiodarone, lidocaine, procainamide) | treat underlying causes