U4 Cardiac Flashcards Preview

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Flashcards in U4 Cardiac Deck (112):
1

Causes of cardiac dysrhythmias

Electrolyte imbalance
Problems with oxygenation
Drug toxicity
CAD

2

Automaticity

Ability to generate an electrical impulse

3

Excitability

Ability of heart cells to respond to electrical impulse

4

Conductivity

Ability to send an electrical signal between cell membranes

5

Contractility

Ability of atrial & ventricular muscle to shorten fibers in response to electrical stimulation

6

Sinoatrial node

Primary pacemaker
Located upper right atrium
60-100 BPM

7

AV node

Secondary pacemaker
Located lower right atrium
40-60 BPM

8

Purkinje fibers

3rd pacemaker
Located at ends of bundle branches
20-40 BPM

9

P wave

Atrial depolarization (contraction)

10

PR interval

Time needed for atrial depolarization & impulses to travel through the heart

11

QRS complex

Ventricular depolarization (contraction)

12

T wave

Ventricular repolarization (relaxation)

13

QT interval

Time needed for ventricular depolarization & repolarization

14

Normal PR

.12-.20 sec

15

Normal QRS

0.06-0.10 sec

16

Normal QT interval

Should be <1/2 of R-R interval

17

Long QT

Can lead to Torsades des pointes

18

Causes of sinus bradycardia

Excessive tone on SA node
Beta blockers (olols)
Calcium channel blockers (verapamil, dilitaxem, nifedipine)
Dig toxicity
Sick sinus syndrome
MI
Hypothyroidism

19

HR <30-46/min

Causes hypotension
Decreased cardiac output
Decreased oxygen perfusion

20

S/S sinus bradycardia

Dizziness
SOB
Chest pain
Hypotension
Shock
CHF
MI

21

Treatment of sinus bradycardia

Atropine--0.5 mg IV up to 3 mg
Oxygen
Monitor for tachycardia after atropine

22

Causes of sinus tachycardia

Increased stimulation from exercise
Anxiety
Pain
Fever
Anemia
Hypoxemia
Hyperthyroidism
Caffeine

23

S/S sinus tachycardia

Usually asymptomatic
If symptomatic, treat the cause (pain, fever)

24

Assessment sinus tachycardia

Decreased BP
Decreased O2 sat
Weakness
SOB
Restlessness
Decreased urine output

25

Premature Atrial Complexes (PAC)

Fires an impulse before next sinus impulse is due

26

Causes of PAC

Stress
Fatigue
Anxiety
Infection
Caffeine
Epi, amphetamines, Dig

27

S/S PAC

Often no symptoms
Treat underlying cause

28

Supraventricular Tachycardia (SVT)

Rapid stimulation of atria--150-280 BPM
Narrow QRS
Usually caused by PAC

29

Paroxysmal Supraventricular Tachycardia

Starts & ends quickly

30

S/S SVT

Palpitations
Chest pain
Fatigue
SOB
Nervousness
Hypotension

31

SVT tx

Adenosine 5 mg
If ineffective, 12 mg IV push
Expect a short period of asystole

32

Risk factors for atrial fibrilation

Age
Hypertension
Previous ischemic stroke/TIA
Heart failure
Diabetes mellitus
Obesity
Alcohol excess (holiday heart)

33

S/S atrial fibrilation

Fatiuge
Dizziness
Palpitations
Weakness
Anxiety
SOB
Hypotension

34

Atrial fibrillation tx

Cardizem (calcium channel blocker)
Amiodarone
Beta blockers
Digoxin
Anticoagulants

35

Atrial flutter

Atrial rate 250-350 BPM
Saw-toothed P-waves

36

Causes of atrial flutter

MI
Rheumatic heart disease
CHF
Ischemia

37

Atrial flutter tx--slow heart rate

Calcium channel blockers
Beta-blockers
Digoxin

38

Atrial flutter tx--convert rhythm

Amiodarone
Propafenone
Sotolol
Felacainide

39

Causes of premature ventricular complexes (PVC)

MI, chronic heart failure, anemia
Hypokalemia
Hypomagnesemia
Caffeine/alcohol
Infection

40

Unifocal PVC

All PVCs look alike
Identical shapes

41

Multifocal PVC

PVCs originate from different places in ventricles
More dangerous than unifocal

42

Bigeminy

Every 2nd beat is a PVC

43

Absolute refractory period

Beginning of Q to middle of T
Heart will stop it

44

Relative refractory period

End of T wave
Heart will let it in

45

R on T phenomena

PVC come in during T wave

46

Ventricular tachycardia

3 or more PVCs in a row
Wide QRS, no P

47

Interventions
V-tach with pulse

Assess to see if pt is stable

48

Interventions
V-tach with pulse & stable

Call Rapid Response
Amiodarone 150mg piggyback
Slow-loading infusion--360 mg over 8 hrs
Maintenance infusion--540 mg over 18 hrs

49

Interventions
V-tach without pulse

Call Code
Start CPR
Epinephrine 1:10,000--1mg IV repeat every 3-5 min
Vasopressin 40 units IV (replace 1st or 2nd dose epi)
Amiodarone 300 mg IV; 2nd dose 150 mg IV push

50

Causes of v-tach

CAD
Hypokalemia
Hypomagnesemia
Heart failure

51

Interventions
V-tach with pulse & unstable

Cardioversion

52

Ventricular fibrilation

No cardiac output
No pulse, no breathing, no BP
No blood perfusion

53

Causes of v-fib

MI
Hypokalemia
Hypomagnesemia
Hemorrhage
Rapid SVT
Shock

54

V-fib tx

Defibrillate
CPR until defibrillator arrives

55

Causes of cardiac arrest

Hypovolemia
Hypoxia
Hydrogen ions (acidosis)
Hypo/hyperkalemia
Hypothermia
Tension pneumothorax
Tamponade, cardiac
Toxins
Thrombosis
Trauma

56

Cardioversion

Elective procedure
Synchronized with QRS
50-200 Joules
Consent form

57

Defibrillation

Emergency
No synchronization
200-360 Joules

58

1st degree AV block

PR interval >.20 sec

59

Causes of 1st degree AV block

Infarction
Ischemic heart disease
Dig toxicity
Electrolyte imbalance
Acute rheumatic fever

60

2nd degree AV block Type I (Wenckebach)

Progressive delay after each P wave until a skipped beat

61

Causes of Wenckebach AV block

Infarction
Ischemic heart disease
Dig toxicity
Electrolyte imbalance
Acute rheumatic fever

62

2nd degree AV block Type II

PR intervals are normal
Skipped beat
QRS sometimes >.12 sec

63

3rd degree AV blpcl

Independent beating of atria & ventricles
P-waves & QRS are constant but at different rates

64

Causes of 3rd degree heart block

Infarction
Ischemic heart disease
Dig toxicity
Electrolyte imbalances
Acute rheumatic fever

65

Class I Antiarythmics

Membrane-stabilizing agents
Decrease automaticity

66

Type IA Antiarrythmics

Treat/prevent SVT, PVC, & tachydysrhythmias
Pronestyl

67

Type IB Antiarrythmics

Treat/prevent PVC, v-tach, & v-fib
Lidocaine, Mexitil

68

Type IC Antiarrythmics

Treat/prevent recurrent PVCs, v-tach, & v-fib

69

Class II Antiarrythmics

Control dysrhythmias associated with beta-adrenergic stimulation
Decrease heart rate
Treat/prevent SVT, PVCs, & tachydysrhythmias
Inderol

70

Class III Antiarrhythmics

Lengthen absolute refractory period & prolong repolarization
Treat/prevent PVCs, v-tach, & v-fib
Amiodarone

71

Class IV Antiarrhythmics

Depresses automaticity of atrial & AV node
Depresses heart rate
Treat SVT, a-fib, & a-flutter
Calcium channel blockers

72

Lanoxin

Controls the rate of a-fib

73

Atropine

Treats bradydysrhythmias
0.5 mg IV up to 3 mg

74

Adenosine

Slows AV node conduction to interrupt re-entry pathways
5 mg
If ineffective, 12 mg IV push

75

Mg Sulfate

Given for refractory v-tach or v-fib
Torsade de pointes

76

Epinephrine

1st line drug for cardiac arrest

77

Vasopressin

Used in place of 1st or 2nd epi dose

78

Dopamine drip

Beta-adrenergic
Increases myocardial contractility & cardiac output

79

Dobutamine drip

Alpha-adrenergic
Improve cardiac output

80

Norepinephrine drip

Alpha-adrenergic effects
Increase perfusion pressure

81

Sodium bicarb

Used w/ pts in cardiac arrest from hypokalemia

82

Isuprel drip

Increase heart rate in transplant pts

83

Midline catheter

3-8 in long
Median antecubital vein
Lasts 1-4 wks

84

PICC line

18-29 in
Antecubital fossa vein
Resides in superior vena cava
Anything can be infused

85

PICC line complications

Central line infection
Phlebitis & thrombophlebitis
Arterial puncture

86

PICC line pt teaching

No limitations on ADLs
Avoid excessive physical activity & heavy lifting
Flush w/ 5 mL heparin daily
Always use 10 mL syringe

87

Non-tunneled central catheter

Subclavian vein in chest or jugular vein in neck
Rate of infection high
7-10 in
Resides in superior vena cava
Short-term use
Flush ports not in use every shift w/ heparin or saline

88

Non-tunneled central catheter insertion

Trendelenburg position
When removing, measure length to make sure it's intact

89

Tunneled central catheters

Portion of catheter lies in subcutaneous tunnel
Rough material cough w/ antibiotics inside to prevent infection
Long-term use

90

Bard powerport

3 palpable bumps on septum
Triangular-shaped port
Noncoring needle is used

91

Nursing Safety--catheters

Assess patency before each use
Any resistance--stop procedure
Aspirate for blood return before flushing
Use small syringe for drawing blood samples

92

Changing administration sets

Clamp tubing
Lay pt flat
Valsava maneuver
Time change to expiratory cycle if pt breathing spontaneously
Time change to inspiratory cycle if pt is mechanically ventilated

93

Pneumothorax

Puncture of lung by introducer or insertion of diret subclavian approach
Dyspnea & tachycardia

94

Hemothorax

Puncture or transection of the subclavian vein or artery
Dyspnea & tachycardia

95

Chylothorax

Transection of the thoracic duct on the left side
Dyspnea & tachycardia

96

Hydrothorax

Transection of the subclavian & placement of catheter into thoracic cavity
Dyspnea & tachycardia

97

Air embolism

Air in central venous system
Chest pain
Dyspnea
Tachycardia
Dizziness
Clamp catheter; L lateral trendelenburg's

98

Arterial puncture

Accessed artery instead of vein
Pulsating bright red blood from introducer needle
Remove immediately

99

Malpositioned catheter

Catheter passed into jugular vein, R atrium, or axygos vein
Pain in ears, neck, or back

100

Catheter migration

Movement of catheter tip into another vein
Causes--coughing, vomiting, heavy lifting
S/S--hearing running stream or gurgling
Stop all infusions

101

Causes of central-line related blood infections

Lack of sterile field during insertion
Inadequate skin antisepsis
Inadequate hand hygiene
Long dwell time

102

TPN risks

Fluid imbalance
Extreme hyperosmolarity (fluid shift)
Increased blood sugar
Fluid overload

103

TPN interventions

Daily weights
Accurate I&O
Monitor glucose & electrolytes--hyperglycemia; hypercalcemia

104

Fat emulsions--fat overload syndrome

Fever
Increased triglycerides
Clotting problems
Organ failure

105

Hemodialysis catheter

Large lumens to accommodate hemodialysis procedure
Don't use catheter for infusion of other fluids/drugs

106

Subcutaneous infusions

Used for palliative care for pts who can't tolerate oral meds, IM injections too painful, &/or IV not available

107

Hypodermoclysis

Slow infuse isotonic fluids into subcut tissue
Max fluid rate 80mL/hr

108

Intraosseous

When vascular access can't be obtained
Used in emergencies

109

Intraosseous complications

Improper needle placement with infiltration
Osteomyelitis
Compartment syndrome

110

Intraspinal infusion

Local anesthetic administered epidurally to block pain impulses
Dr administers 1st dose of medication

111

Intrathecal infusion

Treat cancers that cross blood-brain barrier & involve CNS
Used to treat spasticity of neurologic diseases--cerebral palsy, traumatic & anoxic brain injuries

112

Epidural infusion complications

Check if pt can move legs
Infection
CSF leak
Catheter occlusion
Local infection
Meningitis