Cardiac Rhythms Flashcards
An irregularity or disturbance of the normal electrical activity of the heart
abnormal rhythm
dysrhythmia
taking a breath causes what type of pressure
negative
steps in the cardiac conduction system
1) SA node initiates rate
2) AV node relays atrial impulse to ventricles
3) bundles of His
4) Purkinje fibers- ventricular myocardium
one square on EKG paper is how many seconds
0.04 sec and 1 mm
needed for the diagnosis of heart muscle damage, enlargement of a cardiac chamber, and interruption of some portions of the cardiac conduction system
12 Lead EKG
describe a 12 lead EKG
looks at heart from 12 different angles
a print-out of a single lead or view
rhythm strip
single lead usually is sufficient for identifying basic
dysrhythmias
used for constant 24-hour monitoring in intensive care situations
single leads
how do you calculate the rate on an EKG
count R complex in 6 sec strip and multiply by 10
easy way to remember telemetry
White on Right, Clouds over Grass; Smoke over Fire and Christmas Tree on the bottom
every 15 large blocks is how many seconds
3 sec
simple way to estimate rate
from one R to the next how far apart? Each large square
300, 150, 75, 60, 50, 43
are small pauses in heart rate normal
yes
Dubin’s method can only be used if
the rhythm is regular
depolarization of the chambers _____ their contraction
provokes
When the heart is resting between “beats”, the EKG machine draws a straight line on the paper
isoelectric line
first deflection in the normal cardiac cycle
p wave
what does the p wave represent
depolarization of the atria
why does the depolarization of the SA node appear on EKG
does not generate enough voltage to be seen on the EKG, we assume it occurred to initiate the cycle
After the p wave…
there is a brief return to the isoelectric line, then the QRS complex
what does QRS complex represent
depolarization of ventricles
does the QRS normally point upwards or downwards
could be either, but all the QRS complexes should be pointed in the same direction
what is the duration of the QRS complex
0.04- 0.12 sec or about 1-3 blocks
what does the T wave represent
reploarization of ventricles
is atrial repolarization seen on an EKG
no because the voltage is so low, however it occurd during the QRS complex
what occurs during the PR interval
atria contract/depolarization
(0.12-0.20) or about 3-5 blocks
what organs are nourished by blood first in circulation
heart and brain
what three things do you look at when diagnosing heart dysrthythmias
rate, rhythm, complex
a small increase in what electrolyte will cause the heart to stop
potassium (K)
what are some typical causes of dysrhythmias
Hypoxia
Ischemia
Sympathetic stimulation- stress, trauma, CHF, hyperthyroidism
Medications-antiarrhythmics, bronchodilators, cardiac glycosides, etc.
Electrolyte disturbances- K, Ca and Mg
Stretch or hypertrophy
describe a normal sinus rhythm
rate: 60-100 or about 75
rhythm: regular
PR: upright (0.16)
QRS: 0.06
describe sinus bradycardia
SLOW rate: 23 or < 60 rhythm: regular PR: 0.24 QRS: 0.12
how do you treat sinus bradycardia
atropine or pacemaker
describe sinus tachycardia
FAST, poor fill time rate: 150 rhythm: regular PR: 0.16 QRS: 0.04
describe premature atrial contraction (PACs)
not super concerning, just keep an eye on
*they are usually evident in atrial dysrthymias
P wave comes early
rhythm is irregular
PR: 0.16
QRS: 0.06
describe atrial tachycardia
eventually if left untreated, lungs will fill with fluid
fast rate, cells are overriding the AV node
rate: 150-300
P wave: differs in shape
PR: short, < 0.12
treatment for atrial tachycardia
beta blockers and calcium channel blockers
describe supraventricular tachycardia (SVT)
rate: rapid about 160
cause SOB, chest pain
coming from atria
what is SVT treated with
Metoprolol or *adenosine (slows heart)
describe atrial flutter
hypertrophy of the heart
*all blood is not emptied out of heart
atrial rate: 250-300
*P waves look like FLUTTERS or SAW TOOTH
what is used as treatment for many dysrhthmias if other measures don’t work
cardioversion therapy
describe atrial fibrillation
*most common dysrhythmia* low blood pressure, SOB "quivering", not kicking heart beat no discernible Ps rhythm: always IRREGULAR rate: about 70 wavy baseline
initial drug treatment for atrial fibrillation
Amiodarone
Dilitiazem
broadly describe what heart block is
longer period from SV to AV
ALL types are slow (brady)
describe first degree AV block
don’t do anything, just monitor
PR interval is prolonged (0.36)
rate is regular
bradycardic: 60
another name for second degree Heart Block Mobitz type 1
Wenkebach
describe 2nd degree Wenkebach
rate is slow, progressive*
rhythm is irregular
PR gets longer then drops a beat
(0.2 then 0.24 then 0.26 then drops beat)
describe 2nd degree mobitz type 2
bundle branch delay
drops every other beat
treatment for 2nd degree heart block
atropine: to speed up heart and trigger nerves
ONLY give 3 doses max
treatment for dysrhythmias if pt has pulse
MEDICATION
treatment for dysrhythmias if pt has NO pulse
*dead
compressions (30:2) THEN defib.
describe 3rd degree heart block
- NO coordination between atria and ventricles (INDEPENDENT of eachother)
rhythm: 40-60 - BAD: SOB, chest pain, dizziness
treatment for 3rd degree heart block
pacemaker or atropine(sometimes)
describe premature ventricular contraction (PVC)
no P wave preceding PVC feels like a skipped beat not very concerning unless couplet weird looking beat occur due to pain, fever or low O2
describe couplet PVC
PVC occurring in pairs due to inadequate CO2
this is a problem when they occur in pairs
describe ventricular tachycardia
rapid rate: 150
no Ps or QRS
cardiac output is decreased
heart is irritated
treatment for ventricular tachycardia
if there is a pulse, then amiodarone
what do you always do first BEFORE treatment of dysrhythmias
assess patient
describe polymorphic
no P waves associated with QRS
poor cardiac output
QRS complexes occuring from different foci
what is the procedure for V-fib if no pulse
1)epi 2) compressions 3) amiodarone 4) compressions
describe V-fib
ALWAYS SHOCK- defib
no contraction of heart muscle
only twitching
no cardiac output/sudden death
describe idioventricular
slow rhythm
no P or QRS waves
poor output
