ECGs Flashcards
Bradycardia
<60 BPM
when is intervention needed for those with bradycardia?
when it is severe =< 30 bpm as it will likely compromise cardiac output
summary of ECG finding for bradycardia
regularity?
regular
summary of ECG finding for bradycardia
p wave?
uniform shape
one wave in front of every QRS complex
summary of ECG finding for bradycardia
QRS?
one following each p wave
QRS complexes appear normal
sinus tachycardia
rhythm originating from SA node; rate is too fast
>100 bpm, <160 bpm
summary of ECG finding for tachycardia
QRS?
one following p wave
less than 0.12s (3 squares wide)
summary of ECG finding for tachycardia
t wave?
one following the QRS complex
summary of ECG finding for tachycardia
regularity?
regular
immediate notification is needed if the rate is over ____ or less than ____.
over 180 bpm, less than 30 bpm
atrial tachycardia
single ectopic focus in atria over the SA node regulating heart rate leading to fast regular rhythm but not enough time for vents to fill properly
summary of ECG finding for atrial tachycardia
QRS?
less than 0.12s (3 squares)
summary of ECG finding for atrial tachycardia
rate?
150-250 bpm
summary of ECG finding for atrial tachycardia
p wave?
abnormal shape; one in front of every QRS complex – but sometimes can be hidden in t-wave
atrial fibrillation
multiple foci generating electrical impulses in atria
atria is no longer beating but rather just quivering.
is atrial fib dangerous?
not if ventricles are still functioning ok.
if there is blood pooling at atria and clotting occurs, then it can be life threatening.
summary of ECG finding for atrial fibrillation
QRS?
normal when occurs
summary of ECG finding for atrial fibrillation
regularity?
very irregular
summary of ECG finding for atrial fibrillation
rate?
> 350 bpm
summary of ECG finding for atrial fibrillation
p wave?
no discernible p waves just fibrillatory waves
atrioventricular block
conduction disturbances within AV node
three types of heart blocks
- first degree
- second degree
- third degree
blocks resulting in delay in conduction of impulse from atria to ventricles
1st and 2nd
blocks resulting in the impulse no longer travelling from atria to ventricles
3rd = complete heart block
characteristics of first degree block
- increased PR interval (0.12s to 0.20s)
characteristics of second degree block
- few missed QRS complexes
characteristics of third degree block
- p wave without corresponding QRS complex
if a patient has LBBB, why can we not do stressing with dobutamine?
it can lead to false positive septal defect
what does a notched p wave indicate?
left atrial enlargement
PVC on an ECG
wide QRS complex with T wave in opposite direction
when are PVCs significant?
when there is five or more per minute
or
three or more in a row
or
PVC falling on T wave that ends up triggering ventricular tachy
ventricular tachycardia
series of PVCs causes the ventricles to become irritable and it overtakes the normal pacemaker of the heart
why do myocardial infarcts occur?
due to occlusion or blockage of the coronary arteries causes deprivation of oxygen and nutrients which will eventually cause tissue death
3 components to diagnosis MI
- hx and physical examination
- troponins I and T
- ECGs
trops will be elevated in ___ hours after cellular damage.
6 hours!
ECG changes following acute myocardial infarction
T wave
onset: t waves = tall and narrow, peaking
few hours after: t waves = invert
ECG changes following acute myocardial infarction
ST segment
onset: segment elevated
later: returns to baseline within few hours
ECG changes following acute myocardial infarction
Q wave
new Q waves = MI
appears from hours to several days
and can persists for the life of the patient
significant q wave
indicative of infarction for duration greater than 0.04 secs
1/3 height of R wave
ST segment depression indicate …
myocardial ischemia
myocardial ischemia
lack of blood flow to myocardium to meet the myocardial physiological requirements
ventricular pacemaker on ECG
pacemaker spike followed by wide QRS (shows R vent depolarization then L vent depolarization)
atrial pacemaker on ECG
spike followed by P wave and normal QRS
atrial and ventricular pacemaker
spike - p wave - spike - normal QRS
beta 1 receptors
responsible for heart rate and strength
beta 2
function of smooth muscles (muscles we have no control over)
selective beta blockers
block beta 1 receptors more than beta 2
non-selective beta blockers
block both beta 1 and beta 2 receptors
