disturbances in Rhythm Flashcards
indications for ordering an ECG
- To determine cardiac rate
- define cardiac rhythm
- To diagnose old or new (MI)
- To identify conduction disturbances
- To aid in the diagnosis of heart diseases
3 reasons for using an ECG
detection of ischemia
arrhythmia
hypertrophy
rhythm is used to refer to what
part of the heart which controls activation sequence
12 lead ECG system includes
3 Bipolar leads
3 modified unipolar leads
6 precordial leads
why is there no unipolar lead for the right foot
it fxns as a ground lead
the 6 precordial leads are used to record
horizontal impulses
v4R is the most useful lead in recording a
R-sided ECG
15 lead ecg system is used in
pedia patients
Additional right precordial leads can be used to assess right ventricular abnormalities such as
hypertrophy and infarction
Electrode locations posterior to V6 can be used to help detect what
acute postero-lateral infarction
important in determination of the type of MI
ST-T wave
duration of ventricular depolarization and repolarization
QT interval
rate of atrial or sinus cycle
PP interval
rate of ventricular cycle
RR interval
Duration of P wave
<120 ms
duration of PR interval
120-220 ms
duration of QRS complex
<110-120
duration of corrected QT interval
440 - 460
PR interval is important in determining the presence of
1st deg AV block
Prolonged QT interval may mean
underlying malignancy
T wave represents what?
repolarization of ventricles
how do you monitor atrial repolarization?
electrophysiologic testing
Left axis deviation is seen in
LVH
what is cardiac axis
average direction of spread of the depolarization wave thru the ventricles
Direction of the axis can be derived most easily from
QRS complex in leads I-III
in px w/ 3rd deg AV block the firing of the electrical conduction comes from the
myocardium
medical procedure by which a tachycardic heart or an arrhythmic one is converted to a state of having normal heart rhythm through the
use of electrical impulses or drugs.
cardioversion
RR>100bpm
P wave is present before each QRS and all P waves are identical
PR interval =0.12-0.2
what is this
sinus tachycardia
sinus arrhythmia in the elderly could signify the presence of
sinus node dysfunction
An irregularly irregular sinus arrhythmia could indicate
atrial fibrillation or atrial flutter.
picket fence or saw toothed appearance
atrial flutter
absence of discernible P wave
A-Fib
most common causes of cardiac stroke in the elderly
A flutter and A fib
in this rhythm P wave is either inverted absent or after QRS
Junctional rhythm
in this rhythm there is a prematurely occuring QRS complex that is wide and bizarre looking
PVC
series of PVC
v-tach
why v-tach is not compatible with life
severe amt of v contractions does not allow enough time to fill the v which will lead to cardiac standstill, sudden death is common
2 most common dysrhythmia occuring in the 1st hr of MI that could cause death
v tach and v fib
absenece of any discernible wave form
v-fib
There is extreme sinus bradycardia with irregular idioventricular rhythm and occasional atrial activity.
agonal rhythm
flat line
asystole (ventricular standstill)
this is usu 2ndary to epi or norepi overdose
accelerated idioventricular rhythm
describe a sinoatrial escape
There are the same PQRS complexes but with an atrial escape rhythm.There are the same PQRS complexes but with an atrial escape rhythm
There is progressive prolongation of the P-R interval with each succeeding beat until one P wave occurs without a QRS, that is to say a dropped beat.
2nd degree AV block type 1 wenkebach
There is a dropped beat without prolongation of the P-R interval
type 2 2nd deg AV block
2nd deg AV block is usu due to a block in
AV bundle on the tricuspid
where is the block if vent rate is around 60 and a narrowed QRS complex (3rd deg AVB)
above the bundle of His
Vent rate and QRS in Infrahisian type AVB
V rate is around 40 and wide QRS
