ECG Abnormalities Flashcards
what is a supraventricular rhythm?
one that originates above the AV node, whether conducted through it or not
what is characteristic of a supraventricular rhythm?
narrow QRS complex (<3 small squares)
characteristics on ECG of sinus rhythm?
P wave followed by a QRS
QRS followed by a P wave
PR interval <200ms
what allows for contraction in sinus rhythm?
SA node depolarises, causing atria to contract
delay to conduct to AV node (PR interval)
ventricles contract
characteristics of ECG in sinus arrhythmia?
P wave followed by a QRS
QRS followed by a P wave
PR interval <200ms
irregular rhythm
what can cause sinus arrhythmia?
respiration
characteristics on ECG of AFib?
irregularly irregular QRS complexes
no P waves
ragged baseline
what happens to the conduction in AFib?
disorganised electrical activity
AV node receiving continuous impulses, conducting some of them
difference between AFib and atrial flutter?
AFib is irregular atrial contraction
atrial flutter is regular, but faster than ventricles
characteristics of ECG of atrial flutter?
regular QRS complexes rate divisible into 300 f waves (saw tooth baseline)
leads best to see saw tooth baseline?
what condition is this characteristic of?
V1 and lead II
atrial flutter
what happens to cause a junctional rhythm?
origin of electrical impulse is the AV node as opposed to SA
atria and ventricles simultaneously receive the impulse
characteristics of junctional rhythm ECG?
regular rhythm
normal QRS
no antegrade P wave, retrograde before ST segment and inverted
what is a supraventricular tachycardia?
tachycardia that is generated involving th AV node or above
ECG characteristics of a supraventricular tachycardia?
regular
tachycardia
narrow complex QRS
often no clear P waves
ECG characteristics of a supraventricular ectopic?
regular
occurs on beats 3, 6, 9 etc..
P wave morphology differs
what happens to cause a ventricular premature complex?
ventricles contract before they should
what rhythm is assoc with haemodynamic compromise?
ventricular tachycardia
ECG characteristics of ventricular tachycardia?
regular broad complex tachycardia
QRS >120ms
what is ventricular fibrillation clinically associated with?
loss of consciousness
Hx of MI
ECG changes of ventricular fibrillation?
irregular random baseline
no clear waveforms
what can cause poor R wave progression?
LV failure
failure to remove bra
what happens to cause heart block?
block in conduction between the atria and ventricles due to a problem with the AV node
what can cause damage to the AV node?
ischaemia
drugs
age
features of 1st degree heart block ECG?
fixed broad PR interval
stable length of PR interval
Tx of 1st degree heart block?
none, can be normal
ECG features of Mobitz type 1 heart block?
elongation of PR interval then a dropped beat
Tx of Mobitz type 1 heart block?
may be normal in young, investigate in elderly
ECG features of Mobitz type 2 heart block?
constant PR interval
every other P wave has no QRS
which 2nd degree heart block is abnormal?
Mobitz type 2
ECG features of third degree heart block?
no relationship between P and QRS
ventricular escape rhythm
what is an escaped beat?
late beat from AV node
what is an ectopic beat?
early beat
what can cause pericarditis?
post MI
viral
bacterial
ECG changes in an MI?
upward concave ST elevation
PR depression
widespread in >1 vascular territory
what does non specific inter-ventricular conduction delay show on ECG?
broad QRS that does not exhibit LBBB/RBBB
two types of VT?
monomorphic
polymorphic
what happens in monomorphic VT?
scar is in ventricles from MI
used for electrical impulse
regular rhythm as always same length of travel
another name for polymorphic VT?
torsades des pointes
