Dysrhythmias

Question 1

Automaticity function

Answer 1

ability to general electric impulses

Question 2

Excitability fxn

Answer 2

can respond to outside impulses like chem, mech, elec

Question 3

Conductivity fxn

Answer 3

receive electrical impulses and conduct it

Question 4

Contractility fxn

Answer 4

myocardial cells shorten in response to impulse (pump)

Question 5

How does cardiac conduction occur?

Answer 5

with action potentials!!

Question 6

atrial depol

Answer 6

• contraction of atrium
• p wave
• atrial systole

Question 7

ventricular depol

Answer 7

• ctx of vent
• QRS complex
• vent systole
• bundle of HIS and Purkinjean fibers tell them to get their squeeze on

Question 8

cardiac repolarization

Answer 8

refilling the heart

Question 9

ventricular repol

Answer 9

• t wave

Question 10

SA node

Answer 10

in atria
- stimulates the P wave

Question 11

AV node

Answer 11

• listens to SA
• gatekeeper
• tells vents to squeeze
• stimulates the QRS wave

Question 12

Sinus rhythm

Answer 12

• normal conduction of the heart
• rate 60-100
• reg rhythm
• P wave upright and round, one before each QRS
• PR interval 0.12-0.2 seconds
• QRS under 0.12 seconds

Question 13

Sinus arrhythmia

Answer 13

• another normal rhythm
• variability in HR
• no chx to CO
• HR 60-100
• PR 0.12-0.2
• narrow QRS
• common in younger ppl, assoc with respiratory or ANS fluctuations

Question 14

Dysrythmias

Answer 14

any prob with impulse generation or conduction–abnormality of HR or CO, filling time

Question 15

Causes of dysrhythmia

Answer 15

• inappropriate automaticity - cell initiates AP inappropriately in atrium (MI or electro imbalance)
• triggered activity - extra impulse generated during or just after repol (Dig tox, SNS stim, genetics)
• re-entry - cardiac cell or impulse in one part of the heart continues to depol after main impulse is done (MI or electro)

Question 16

What does “sinus” indicate

Answer 16

SA node prob

Question 17

Sinus brady

Answer 17

• rate under 60 bpm
• normal rhythm
• normal PR int and QRS
• caused by hyperK, vagal response, digoxin tox, late hypoxia, olol, Ca block, amio, MI
• CM: dec CO, lightheaded, dizzy esp wit exert, syncope, chest pain, dyspnea, conduction, easy fatigue
• tx is atropine or pacemaker

Question 18

What should you do before acting with sinus brady?

Answer 18

ASSESS FOR SX

Question 19

Sinus tachy

Answer 19

• HR 100-150
• reg rhythm
• P waves similar (may be partial hidden)
• normal PR and QRS
• caused by catecholamines, fever, FVD (tachy is first), meds (beta, albuterol), coffee, nic, cocaine, EARLY hypoxia
• tx based on cause (fluids, antipyretics, analgesics, beta block if needed)

Question 20

Paroxysmal supraventricular tachy (PSVT)

Answer 20

• occasional and fast
• above the SA node
• 150-200 bpm
• originates in AV node
• usually no “p” wave or abnormal if present
• normal QRS
• usually r/t reentry phenomenon
• start, stop quick
• “heart racing”
• causes: overexert, stress, stims, dig tox, rheumatic CHD, CAD, WPW sx, R side HF
• s/s: palpits, chest pain, fatigue, dyspnea, lightheaded, dizzy

Question 21

Premature atrial ctx (PACs)

Answer 21

• early p waves that look a little diff (morph chx)
• normal PR and QRS that follow P wave
• if freq–pt high risk for other dysrhythmia (usual afib)
• tx: check electros, may need O2 (hypoxia)

Question 22

Atrial flutter

Answer 22

• originates in AV node and overrides SA node
• reentry impulse that is cyclic and repetitive
• atrial contraction at reg rhythm but quick rate >250
• vent rate slower (QRS) and narrow
• P wave classic sawtooth look
• 2:1, 3:1, 4:1
• caused by CHF, cardiomyo, valve disease, heart inflam, HTN, lung disease, electro, overactive thyroid, heart surg

Question 23

A-fib

Answer 23

• irregular irregularity from lack of comm btwn atria and vent
• HR 100-175 or lower
• no identifiable P wave or even T
• fibrillation waves
• CM - racing, fatigue, dizzy, papits, dicomfort in chest, SOB, asymp
• caused by electro, hypoxia, CVD

Question 24

What do you need to know about a-fib?

Answer 24

IF THE RATE IS CONTROLLED

Question 25

a-FIB complications

Answer 25

HF, dec CO, embolus
- STROKE bc blood not pumped like it is meant to

Question 26

a-fib tx

Answer 26

CONTROL RATE
- olol, CCB, digitalis
- prevent stroke - anticoag/plt
- ablation and cardioversion

Question 27

Pre-vent contraction (PVCs)

Answer 27

• ctx from ectopic focus in the vents
• early QRS, no p waves or normal rhythm, or negative QRS
• wide and distorted shape - QRS
• cause - electro, hypoxia, stims, fever, exercise, stress, CVD
• tx the cause

Question 28

V tachy

Answer 28

• 3+ PVCs together
• ectopic focus in vents takes control and fires repeated - no atrial ctx occurs
• V dec CO
• assoc with MI, CAD, insignificant electro abnorm, HF, drug tox
• DEADLY RHYTHM
• 150-200 bpm, usual regularity
• no p-wave
• PR immeasurable

Question 29

V tachy tx

Answer 29

• treat ACLS - depend on if palpable pulse
• pt v symptomatic unless converts back to other rhythm
• may need anti-dysrhythmic med like olol or CCB or electro replace
• if sustained v-tach, check pulse, CPR

Question 30

First question to ask about V-tachy?

Answer 30

Are they symptomatic?

Question 31

V-fib

Answer 31

irregular waveform of varied shape and size
- vents quivering
- no effective ctx and NO CO
- CPR may be needed