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71 Cards in this Set

  • Front
  • Back
see electrical activity of the heart
must check pulse and VS to confirm
SA node
pacemaker - first
60-100 bpm
depolarize atria
AV node
1. slows impulse for atrial kick = 10-20% more blood
2. back-up pacemaker = rate of 40-60 bpm (junctional/nodal rhythm)
bundle of HIS
continuation of AV node
purkinje system
1. carries impulse to ventricular conducting cells
2. back-up escape pacemaker (20-40 bpm)
sequence of cardiac activation
SA node
rt then left atria (systole - blood to relaxed ventricles)
AV node (slows)
bundle of HIS to purkinje fibers
ventricles (systole - blood out)
action potential
1. action phase - depolarization= change in permeability; enough sodium in/potassium out

2. resting phase - repolarization - sodium out, potassium in via active transport
P wave
atrial depolarization
upright, rounded, less than 0.12 seconds, 1 per cycle
QRS complex
ventricular depolarization (intraventricular conduction time)
down (Q), up (R), down (S)
interval - lasts 0.06 - 0.12 seconds
T wave
ventricular repolarization - return to resting state (ventricles are filling with blood)
upward, downward, indicator of ischemia
PR interval
electrical impulse down atrium to AV node (beginning of P wave to beginning of QRS)
0.12 - 0.20 seconds
longer = delayed conduction
ST segment
early repolarization of ventricles
can indicate myocardial injury
end of QRS to beginning of T wave
U wave
not normally present
indicates hypokalemia
Lead II
upright waves
positive electrode in midclavicular 5th intercostal space
downward waves
positive electrode in 4th intercostal space to right of sternum
ECG paper
1 mm sq = 0.04 seconds, 5 squares = 0.20 seconds
isoelectric line
baseline tracing
waves either above or below (positive or negative)
5 steps to evaluate
1. rhythmn - R to R or P to P are the same (regularly irregular or irregularly irregular or regular)
2. Rate - 60 to 100 bpm
3. P wave - upright, after QRS, look alike
4. PR interval - 0.12 to 0.20 seconds, look alike and contant
5. QRS complex - less than 0.12 seconds, look alike and constant
normal sinus rhythm
1. 1 upright and consistent P wave before each QRS
2. All PR between 0.12 and 0.2 seconds
3. consistent QRS of less than 0.12 seconds
4. consistnet R-R interval
5. HR of 60-100 bpm
loss of rhythm, regularity of heart
abnormal, disordered, or disturbed rhythm
most accurate
causes of dysrhythmia
1. disturbance in formation of impulse
2. disturbance in conduction of impulse
unstable rhythm = hemodynamic instability
altered mental status
chest pain
difficulty breathing/CHF
SA node dysrhythmia
usually 60-100 bpm
generally not dangerous
sinus bradycardia
rate of less than 60 bpm
everything else is normal
causes of sinus bradycardia
meds (Ca channel blockers, beta blockes, dig)
vagus nerve stimulation
acute coronary syndrome
S&S of sinus bradycardia
fatigue, dizzy, SOB, weakness, syncope, hypotension, CHF, chest pressure, tightness, pain
management of sinus bradycardia
no atropine for postcardiac transplant patients
O2, IV
ACLS algorithm - atropine, transubutaneous pacing, dopamine, epi, isoproterenol
sinus tachycardia
HR faster than 100 BPM (101-180)
everything else is normal
sinus tachycardia causes
physical activity, hemorrhage (1st SIGN), shock, meds, dehydration, fever, MI, electrolyte imbalance, fear, anxiety, compensate for hypoxia
S&S sinus tachycardia
angina, dyspnea, increases heart's workload
sinus tachycardia management
meds - dig, CCB, beta blockers
treat CAUSE!!!!
atrial dysrhythmias
atria can become primary pacemaker if they fire faster than SA node
rhythm generally 100-200+ bpm
P waves will look different
supraventricular dysrhythmia
less than 0.12 seconds for QRS, normal
problem is above ventricles
ventricular dysrhythmia
greater than 0.12 seconds = wide QR complex
problem is in ventricles
premature atrial contactions
atria fire before SA node
shortened R to R interval
causes of PAC
hypoxia, smoking, stress, MI, enlarged atria in valvular disorders, meds (dig), electrolyte imbalances, atrial fibrillation, heart failure
S&S of PAC
generally none, possible palpitations
CN 3 output to ocular muscles is primarily affected by
vascular diseases (DM) due to decreased diffuse to the interior
atrial flutter
atria flutter at 250-350 bpm
F waves instead of P waves, picket fence appearance
may have normal QRS complex
atrial flutter causes
rheumatic, ischemic heart disease, CHF, hypertension, pericarditis, PE, post-op CABG
atrial flutter rules
1. rhythm is regular or irregular
2. HR varies
3. P waves into F waves
4. PR interval - not measurable
5. QR complex is less than 12 seconds
S&S of atrial flutter
none, sometimes palpitations, angina, dyspnea
managing atrial flutter
control ventricular rate, convert rhythm
cardioversion (greater than 150 = stat)
CCb + beta blockers control rate
digoxin converts rhythm
quinidine, procainamide, propranol slow HR
atrial fibrillation
rapid and chaotic atrial rate - 250-600 bpm
ventricular rate lower as AV node blocks most impulses
atrial fibrillation complications
increased risk of thrombus due to poor emptying of atrial blood
left ventricular failure
rule of atrial fibrillation
rhythm - irregularly irregular
HR - atrial not measurable, ventricular either controlled (under 100 bpm) or rapid (over 100 bpm)
P waves - no identifiable
PR waves- none measured becuase no P waves
QRS complex - 0.06 seconds to 0.10 seconds)
causes of atrial fibrillation
rheumatic, ischemic heart disease, heart failure, hypertension, pericarditis, PE, post-op coronary artery bypass surgery
symptoms of atrial fibrillation
feel irregular rhythm - palpitations, skipping heart beat
faint radial pulse due to decreased stroke volume
atrial fibrillation management
unstable: cardioversion stat
stable meds (CCB, BB, dig), anticoagulant therapy, cardioversion
also: dual chamber pacing, implanted cardioverter defibrilators, ablation, maze)
meds for atrial fibrillation
dofetilide, quinidine, flecainide, propafenone, ibutilide IV
premature ventricular contractions
occur before SA
ectopic focus (other than SA node)
wide and bizzare QRS complex
PVC shapes
unifocal - originate from one spot
multifocal - several irritable areas (look different)
bigimeny - every other beat
trigeminey - every third beat
quadgeminy - every 4th beat
couplet - 2 together
run/ventricular tachycardia = 3 or more together
causes of PVC
alcohol, caffeine, anxiety, hypokalemia, cardiomyopathy, ischemia, MI
PVC rules
1. rhythm - interrupted
2. HR - depends on rhythm
3. P waves - absent before PVC QRS complex
4. PR interval - none for PVC
5. QRS complex- greater than 0.12 seconds, t wave in opposite direction of QRS complex
S&S of PVC
skipped beat, palpitation
decreasd cardiac output = dizzy, fatigue, severe dysrhythmias
PVC interventions
needed only if more than 6 a minute, regularly occuring, multifocal, fall on t-wave, caused by acute MI

meds: procainamide, lidocaine
ventricular tachycardia
3 or more PVCs in a row
causes of VT
myocardial irritability, MI, cardomyopathy
also respiratory acidosis, hypokalemia, dig toxicity, cardiac cath, pacing wires
VT rules
1. rhythm: regular
2. HR: 150-250 BPM, slow is below 150 bpm
3. P waves: absent
4. Pr interval: none
5. QRS complex: greater than 0.12 seconds
S&S of VT
sudden onset of rapid heart rate
dyspnea, palpitations, light-headed
cardiac arrest
management of VT
may need CPR, defib
stable: meds (amiodarone, procainamide, sotalol, lidocaine, phenytoin, BB; also magnesium)
ventricular fibrillation
many ectopic ventricular foci fire at same time
chaotic ventricular activity - no waves
ventricle cannot initiate contraction
causes of ventricular fibrillation
hyperkalemia, hypomagnesemia, electrocution, CAD, MI, surgery
ventricular fibrillation rules
1. rhythm: chaotic, irregular
2. heart rate: not measurable
3. P waves - none
4. PR interval - none
5. QRS complex: none
ventricular fibrillation S&S
lose consciousness
no heart sounds, no peripheral pulses, no blood pressure
respiratory arrest, cyanosis, pupil dilation
ventricular fibrillation management
Endotracheal entubation, ventilation for respiration
meds: epi, vasopressin, amiodarone, lidocaine, magnesium, procainamide
absence of electric activity in cardiac muscle; usually preceded by ventricular fibrillation
asystole causes
ventricular fibrillation, loss of cardiac muscle due to MI
asystole rules
rhythm: none
heart rate: none
p waves: none
Pr interval: none
QRS complex: none
asystole management
CPR, endotracheal intubation, transcutaneous pacing, epi/atropine