Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NSG 478 > Cardiac Conduction Problems Part 1 > Flashcards

Cardiac Conduction Problems Part 1 Flashcards

1
Q

Arrhythmias

A
  • Disorders of Electrical impulses or conduction within the heart
  • Can cause disturbances of the HR, heart rhythms or both
  • Can cause changes in hemodynamics due to changes in pumping action
  • Diagnosed by ECG
  • Treatment is based on the frequency and severity of symptoms produced
  • Named according to site of origin of the electrical impulse and mechanism of conduction involved.
    • For example if impulse originates in SA (Sinoatrial node) node, and the rate is above 100 its Sinus Tachycardia
    • Conduction should start in the SA node but heart blocks and arrythmias can interupt that
    • If the conduction starts in SA node its sinus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Normal electrical flow through the heart

A
  • SA
  • AV
  • Bundle of his
  • Bundle branch
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Main pacemaker of the heart

A

SA node,with a normal electrical stimulus of 60-100 impulses per min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Stimulation of the sympathetic nervous system results in

A
  • Positive Chronotropy
  • Positive dromotropy
  • Positive inotropy
  • Constriction of peripheral blood vessels which increase BP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Stimulation of the parasympathetic nervous system

A
  • reduces HR, AV conduction, and force of atrial contraction
  • Reduction of BP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Diagnostic workup of cardiac arrhythmias, to identify cause vs problems with the heart itself

A
  • ECG and echo
  • Labs with chemistries (K, Mg, Ca, Na) and BNP (HF), thyroid function test, CBC
  • Dig levels if appropriate
  • Cardiac enzymes if MI (Troponin)
  • CT and MRI and D-dimer if PE suspected
  • Chest X-ray
  • Exercise testing; holter monitoring
  • Electrophysiology studies
  • Cardiac cath
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Electrophysiology studies

A

Setting the pt into the rhythm to see how they act or see cause

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why echo for arrythmias

A

Echo can see EF and reduced EF can lead to arrhythmias

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

P wave

A

Atrial depolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

PR interval

A
  • Start of P wave (Atrial depolarization) to the start of ventricular depolarization (Start of Q wave)
  • the PR segment is the end of the P wave to the start of the Q wave

Normal is 0.12-0.2 sec 3-5 boxes

Find a p wave that starts on a line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

QRS complex

A

Ventricular depolarization

Normal is 0.8-0.12 seconds, 2-3 boxes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

T wave

A

Ventricular relaxation (repolarization)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

QT interval

A
  • Start of Q wave to end of T wave
  • Drugs can prolong this (antidepressants and such)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How long is one small box, ECG (1mm)

A

0.04 seconds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How long is a large box, ECG (5mm)

A

0.2 seconds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do you calculate the HR using an ECG

A
  • Count the QRS complex (Only regular rhythms)
  • Most strips are a standard 6 seconds, so multiple the number by 10
  • Easy but not accurate

Normal is 60-100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Calculating the rhythm

A
  • Determine if it is regular or irregular
  • Measure from R wave to R wave
  • If irregular is there any pattern to irregularity
  • Is there a P wave for each QRS (Very important for heart blocks and arrythmias)
  • For heart blocks check the pr ratio
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Calculating the rhythm: P wave

A
  • There should be one P wave for each QRS (Is there more than one)
  • Are the P waves rounded?, are they notched or peaked? (Each P wave should look the same)
  • All P waves should look essentially the same in size shape and direction to be considered normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Sinus bradycardia

A
  • Same as normal sinus but HR is under 60 bpm
  • Normal when sleeping or athletes
  • Persistent brady can cause decreased CO
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Causes of sinus brady

A
  • Valsalva maneuver
  • Vagal stimulation
  • Sleep apnea
  • Hyperkalemia
  • Hypoglycemia
  • Increased intracranial pressure
  • Disease of SA node
  • Admin of drugs (Dig, CCB, BB)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Treatment of sinus brady

A
  • None
  • If symptomatic however you give Atropine, temp or perm pacemaker, Treat the cause
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Sinus Tachycardia

A
  • Same as Normal sinus but over 100 bpm
  • Normal after exercise
  • Can lead to decreased CO and decreased BP due to there not being enough time for the heart to fill with blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Causes of sinus tachy

A
  • Fever
  • Pain
  • Hypoxia
  • PE
  • HF
  • Hypovolemia/hypotension
  • Stress
  • Anxiety
  • Drugs that increase sympathetic tone (Epi, NE, DA, Dobutamine, isoprotenrenol, nitroprusside
24
Q

Treatment of sinus tachy

A

Treat the cause

25
Q

Overview of sinus arrhythmias

A
  • All are regular
  • All have a P wave for a QRS complex
  • QRS with is the same for all
  • PR intervals are within normal limits
  • Rates are the main thing differing
26
Q

Sinus arrhythmias (normal one)

A
  • Time between beats can be slightly shorter or longer depending on whether youre breathing in or out
  • HR increases when breathing in
  • HR slows when exhaling

Considered normal

27
Q

How much does the Atria contribute to CO

A

25-30% with the atrial kick, with arrhythmias this will significantly decrease CO

28
Q

Atrial arrhythmias

A
  • Ectopic sites on the atrium, that generate an impulse, some are blocked at the AV node some are not
  • A-fib, a-flutter, SVT
  • SA to av node transmission is impaired
29
Q

A-fib

A
  • Irregular Heart rhythm originating from an ectopic site in the atria, usually rapid when it first occurs
  • Atrium depolarizing at a rate greater than 400 bpm, with the majority of impulses being blocked at the AV node
  • AV node conducts impulses irregularly and randomly leading to an irregular ventricular rhythm
  • As a result of 400 bpm the atria does not beat but quivers like a. bag of worms
  • Very common
  • causes loss of atrial kick, decreasing CO
  • Blood clots are super common due to pooling of the blood in the atria
30
Q

Causes of A-fib

A
  • Strongly associated with diseases (HF, CAD, Valve disease, pulmonary disease, DM, HTN) Common after cardiac surgery as well
  • Sometimes previpitated by exertion, sleep, caffine and alc
31
Q

Rapid ventricular rate A-fib

A
  • HR exceeding 100 in a-fib
  • Increases myocardial oxygen demands, increases cardiac workload, decreases cardiac output
32
Q

Treatment of afib: Control of clots

A
  • Anticoagulants: Prevent clot formation due to high risk of stroke with A-fib
  • Dabigatran, Ravaroxaban Apixaban warfarin
  • Lovenox and heparin
  • Stroke risk assessment (CHA2DS2-VASc score)

Super duper important

33
Q

Treatment of afib: Control of rate

A
  • Beta blockers
  • Calcium channel blockers diltiazem (Cardizem)
  • Dig

Rapid afib is dangerous

34
Q

Treatment of afib: Tachybrady syndrome

A
  • HR flips between Tachycardia and bradycardia, so if you give a BB for example it might crash their HR
  • Needs a pacemaker to place a perm rhythm that prevents brady
35
Q

Treatment of afib: Rhythm control

A
  • Cardioversion (Electrical shock and conversion to sinus)
  • Meds (Flecainide, Propafenone, Dofetilide, Sotalol (First line agents)) Amiodarone
  • Ablation: Radiofrequency cath based, MAZE procedure during CABG
36
Q

Ablation for A-fib

A
  • Cath is inserted into the heart from femoral area, up onto where the arrhythmia is coming from,
  • Area of concern is identified and is burnt or frozen to damage the affected area
  • Once completed the cath is removed and incision is closed
  • Takes 4 hours
37
Q

A-Fib and stroke

A
  • Huge risk for a-fib, due to pooling of blood in the aria, left atrial appendage
38
Q

A-fib on ECG

A
  • Irregularly irregular
  • Atrial rate of 400-600, not measurable
  • PR, not able to determine (No P wave)
  • No P wave only fibrillary waves
  • QRS is normal (Its above the bundle of HIS)
  • Ventricular rate is normal or fast
39
Q

Atrial flutter

A
  • Similar to a fib, except its a sawtooth pattern except fib
  • A flutter originates in an ectopic site in the atria
  • Atrium depolarizes at a rate of 250-400 bpm
  • AV node blocks at least half the impulses to the ventricles

More of an electrical issue than a cardiac issue, unlike a-fib

40
Q

A flutter: Conduction ratio stays the same

A

ventricular Rhythm will be regular

41
Q

A flutter: conduction ratio varies

A

Ventricular rate will be irregular

42
Q

T/F A flutter is a chronic condition

A

False, it is uncommon for it to be chronic but not impossible. Usually it converts to A fib or sinus (Spontaneously or following treatment)

43
Q

Atrial flutter on ECG

A
  • Atrial rate of 250-400 (can count if slow)
  • Abnormal P waves (Sawtooth/flutter waves)
  • PR unable to determine (Too many P waves)
  • Rhythm may be regular or irregular
  • Varying degree of flutter waves can be measured per QRS complex (2:1, 3:1 …)
  • Treatment is the same as A-fib
44
Q

How does A-fib differ from A-flutter: Cause

A

A-fib is caused more often from cardiovascular issues such as IHD, HTN, high cholesterol , nicotine, DM

A flutter is less common and usually due secondary to an abhorrent electrical pathway in the atria

45
Q

Paroxysmal A-fib

A
  • A-fib that occurs intermittently and stops spontaneously within 7 days
  • Dangerous because of risk of shooting a clot to the brain when it resolves
46
Q

Persistent A-fib

A
  • Last longer than 7 days
  • May require cardioversion to restore sinus rhythm
47
Q

Long standing A-fib

A
  • Similar to persistent but last longer than a year
48
Q

Paroxysmal or Supraventricular Tachycardia (PAT/SVT)

A
  • Originates due to an ectopic pacemaker site in the atria
  • Atrial rate of 140-150
  • May start and stop abruptly
  • Continuous rhythm or short burst of SVT
  • Rapid ventricular rate, decreased ventricular filling
49
Q

Is SVT a ventricular or atrial arrythmia

A

Atrial

50
Q

Clinical manifestations of SVT

A
  • Palpitations
  • Fatigue
  • Exercise intolerance
  • mild dyspnea
51
Q

Causes of SVT

A
  • CAD or mitral valve disease
  • Nicotine
  • Stress/anxiety
  • Caffeine/alc
  • Fatigue
  • Lung disease (COPD)
  • Hyperthyroidism
  • Dig tox
  • More common in women
52
Q

Mgmt of SVT

A
  • Vagal maneuvers: (try and poop your pants), coughing, holding breath, carotid massage (not really)
  • Adenosine IV (Drug of choice)
  • Calcium channel blockers (Cardizem), BB
  • Pacemaker
  • Cardioversion
  • Ablation
53
Q

SVT on an ECG

A
  • HR is 150-250 bpm
  • Rhythm is usually regular
  • P waves are hidden in T waves, the TP wave is distinguishing feature of this rhythm
  • PR is non existent
  • QRS is narrow (fast)
54
Q

Adenosine

A
  • Given IV
  • 6mg dose followed by 20 mg saline slammed
  • Stops heart temp but it should start back up
55
Q

Prolonged QT interval

A
  • Delayed repolarization of the myocardium
  • Normal QT interval is <440 msec
  • Can progress to ventricular arrhythmias, (Torsades de pointes)
  • mgmt is Mg
56
Q

Causes of prolonged QT interval

A
  • Lots o drugs
  • Hypokalemia
  • Hypomag
  • Certain arrhythmias
  • Stroke
  • HF

NSG 478 (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions