• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/55

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

55 Cards in this Set

  • Front
  • Back

List three causes of sinus bradycardia

1. acute inferior MI


2. high sympathetic blockade (high spinal)


3. Strong vagal input to the SA node


-hypersensitive baroreceptors


(Carotid Sinus Syndrone)


What is the cause of carotid sinus syndrome?

Hypersensitive baroreceptors due to accumulation of atherosclerotic plaque in the carotid areteries.



Slight neck stimulation will trigger reflex bradycardia.

LIst three potential p-wave changes associted with a junctional rhythm

1. short PR interval


2. no p wave


3. p wave after QRS complex

List two characteristics of an idioventricular rhythm

1. HR 40-60 beats/min


2. Wide QRS

List two mechanisms that cause tachycardia

1. Enhanced automaticity


-inflammation


-chemical agent (catecholamine, caffiene, nicotine)


-mechanical irritation (cardiac catheter)



2. Ischemia giving rise to re-entry pathway

What is the most common perioperative dysrhythmia?

Sinus tachycardia

What heart rate is normally seen with sinus tachycardia?

100-150 bpm

List some causes of sinus tachycardia (6)

Pain (light anesthesia)


Anxiety


Hypovolemia (hemmorrhagic/shock)


Exercise


Malignant Hyperthemia


Thyrotoxicosis

If SVT begins and ends suddenly it is called _____________

Paroxysmal SVT (PSVT)

Atrial tachycardia due to an ectopic focus is caused by enhanced _________ due to phase _______ depolarization of some focus in the atrium

enhanced automaticity


phase 4 depolaization


(caused by "funny" channels)

Atrioventricular node re-entrant tachycardia (AVNRT) is caused by _______ pathways in the AV node

two

Describe the pathways involved in atrioventricular node re-entrant tachycardia (AVNRT)

fast pathway - has slow recovery


slow pathway - has fast recovery



In AVNRT, the re-entrant loop is created through the pathways. ___________ conduction via the slow pathway, and ___________ conduction via the fast pathway.

anterograde conduction via the slow pathway



retrograde conduction via the fast pathway

Are P waves present in AVNRT?

No

List the two causes of atrioventricular re-entrant tachycardia

1. Wolf - Parkinson - White Syndrome (WPW)



2. Lown-Ganong-Levine Syndrome (LGL)

What is the atrial rate seen in atrial flutter?

250-350 bpm

What is the normal conduction ratio seen in atrial flutter?

2:1 or 3:1

Atrial flutter likely results from re-entry secondary to which conditions (3)?

Pulmonary embolism


Coronary artery disease


Valvular disease (mitral stenosis)

In junctional tachycardia, the ectopic focus or re-entry pathway is located where?

The bundle of His

Wide complex tachycardia orginates where?

In the ventricles

The normal QRS duration of wide complex tachycardia is:

>120 ms

Premature beats are also known as ____________

Extrasystoles

If the ventricular conduction pathway is refractory, an atrial preamture beat will result in:

An abnormal QRS


(APB with aberrant ventricular conduction)

The difference between an APB and the following sinus beat is normal in duration. Why?

Because retrograde conduction from the ectopic focus "resets" the SA node.

List three characteristics of a PVC

1. wide QRS > 120 ms


2. Prominant R or S wave


3. May have large, inverted T wave

Because a PVC is not conducted back to the SA node, ____________ results

A compensatory pause (because the SA node is not reset)

Ventricular Premature Beats comprise _______ percent of all dysrhythmias during anesthesia

15 percent

If a VPB is closely coupled with the preceeding beat, what can happen?

R on T phenomenon. Can lead to ventricular tachycardia or ventricular fibrillation.

List three areas of the heart where conduction defects are prone to occur:

1. in and around the SA node (SA exit block)


2. Within the AV node


3. Within the conduction system of the ventricles (bundle branches & fascicles)

First degree AV block is characterized by a PR interval longer than ___________

0.20 seconds

Second degree AV block (Mobitz I) is also known as ___________

Wenckebach phenomenon

Second degree AV block (Mobitz I) results in what?

Progressively lengthening PR interval until dropped QRS complex.

T/F Mobitz I blocks are at high risk for progressing to complete AV block

False. - This is more likely to occur with Mobitz II

What is the distinguishing characteristic of a Mobitz II block?

Loss of AV conduction after a constant PR interval (ex. conduction of every other beat)

T/F Mobitz II is more serious than Mobitz I

True - more likely to progress to complete AV block.

If the block is below the AV node within the bundle of His, what will the ECG look like?

Wide QRS

What is 3rd degree AV block?

P waves and QRS complexes at independent frequencies

What is Stokes-Adams syndrome?

Intermittent complete AV block.


Fainting followed by initiation of junctional or ventricular escape.

In a right bundle branch block an abnormal QRS will often be visible in which EKG leads?

V1 and V2

What type of QRS complex will be seen in a right bundle branch block?

rSR' (often two separate peaks)

What can cause a right bundle branch block (2)?

Chronic lung disease


Atrial septal defect

A left bundle branch block often causes prolonged QRS complex in which leads?

I and V6

How does the QRS complex change in a left bundle branch block?

Wide, notched, "rabbit ears" appearance

In bundle branch blocks the mean electrical axis shifts _______ the block

Toward

Which type of hemiblock is most common?

Left anterior fasicular block

What EKG changes show up in a LAFB?

Q wave in lead I


S wave in lead III


Left axis deviation

What EKG changes show up in a RAFB?

W wave in lead III


S wave in lead I


Right axis deviation

What causes fibrillation

Asynchronous electrical activity.


Often caused by circus movements of multiple impulses.

What is the hallmark EKG sign of wolf-parkinson-white syndrome?

Short PR interval


Delta wave - caused by premature depolarization of the ventricular septum.

Which type of dysrhythmia does WPW syndrome develop into?

SVT - atrioventricular reentry tachycardia (AVRT)


Explain how WPW syndrome develops into AVRT

Normally conducted impulse re-enters the atria in a retrograde manner and re-activates the atria.

What happes to the delta waves when WPW develops into AVRT?

They dissapear because the re-entrant circuit is now sending impulses to the atria (instead of the ventricular septum)

What is the anatomic basis of WPW?

An abnormal Kent Bundle that transmits impulses from the atria to the ventricular septum.

What EKG changes differentiate Lown-Ganong-Levine Syndrome from WPW?

No delta wave


(LGL DOES have short PR interval)

Lown-Ganong-Levine Syndrome (LGL) usually results from what?

Abnormal conduction (bypass) pathway from the atria to the AV bundle.