ECG Flashcards
Which lead is mostly used to detect p waves?
Lead 2,
V1 & V5 rythem
Define sinus bradycardia? Sinus Tachycardia?
Sinus rhythm with rate < 60/ minute is called Sinus bradycardia
Sinus rhythm with rate > 100/min is called Sinus tachycardia
define arryhthemia?
abnormal rate and/or rhythm of the heartbeat
Describe atrial fibrillation on an ECG?
And its effect of heart rate & pulse
causes?
Multiple atrial foci! its caotic!
Multiple vectors pointing at different places at different directions >> UNORGANIZED
NO P WAVES
just wavy baseline!
Narrow QRS complexes
Atrial quivers! does not contract!
Pulse and beart rate IRREGULARY irreugular
350-650 bpm
**anything that causes enlargment of the atrium>>associated with atrial fibrillation
define heart block
What r some causes of a heart block?
This occurs when the electrical impulses are partially or fully blocked between the atria and the ventricles.
- MI>> most common
- degenerative changes
what is the ventricular escape rythem?
/
how many types of heart block r there?
3
Describe 1st degree heart block
slight delay in the time it takes electrical pulses to move through the AV node.
First-degree heart block rarely causes any noticeable symptoms
- P wave normal
- delay in AV node is LONGER>> longer PR-interval
(5 small squares)
- slower conduction in AV node
- QRS is normal
what is Wenkebach phenomenon?
Mobitz 1 (Wenkebach phenomenon)
Describe briefly 2nd degree heart block
impulses from the atria are not conducted through to the ventricles.
eventually lead to a heartbeat being skipped
describe 2nd degree heart block type 1!
Mobitz 1 (Wenkebach phenomenon)
PR interval keeps getting longer and evetually it doesn’t make it to the ventricles! (they kept waiting and waiting for their turn until one eventually died)
until u get a ‘DROPPED BEAT” (when p wave is not filled by a QRS complex)
describe 2nd degree heart block type 2
-Mobitz 2
PR interval is NORMAL, it normal FAJ2A ykhtrb (sudden non-conduction of beat) Dropped QRS >>>>>>HIGH RISK OF PROGRESSING TO TYPE 3 COMPLETE BLOCK
difference btw mobitz 1 & mobitz 2 on an ecg
In mobitz 1= each time it conducts PR interval PROGRESSIVELY LONGER EACH TIME!
In mobitz 2= each time it does conduct> PR interval is the same! ( not delayed)
Describe 3rd degree heart block
COMPLETE BLOCK
***normal atrial depolarisation BUT none of atrial waves go to ventricles!
- atrial and ventricles r dissociated
- ventricular pacemaker takes over (ventricular escape rhythm)
- SLOW HEART RATE 30-40 Bpm>>too low to maintain bp and perfusion
- usulally wide QRS complexes
- ECG= even though atria is working normal, none of those signals r going down to ventricles & ventricles struggle with escape beats at a very low rate! (30-40 bpm)*
even
what is the heart rate in 3rd degree heart block? explain why
30-40 bpm
so slow!!! bc atria and ventricles r completely dissociated and ventricles depolarise at their pwn rate which is slower!
in 3rd degree heart block, where is the block most likely to be?
AV node, bundle of his
what does idiopathic mean?
unknown cause
describe ventricular fibrillation and how it leads to cardiac arrest?
- u get impulses from many ECTOPIC sites firing in ventricular muscle>this results from a ventricular flutter.
- ventricles quiver, abnormal FAST ventricular depolarisation.
- many ectopic firing mn kl mukan> cause ventricles to rapidly work> NO CO>> cardiac arrest> DEAD
- kind of like rowing a boat, it rows best if everyone rows at the same time. but if each person rows 3ala kaifa, the row boat will move in cricles and evetually sink!*
how would ventricular fibrillation appear on a ecg?
how can we manage this?
the whole PQRST breaks down completely!
- we need to De-fibrillate (give external stimulation)
its a high energy shock that will depolarize everything at once to allow the SA node to take control again!
(just like when the leader shouts on the rowers to start rowing properyl!)
how is ventricular fibrillation and atrial fibrillation different?
in atrial fibrillation, some beats got irregular. but some beats can be conducted to the ventricles, and ventricles depolarizes and contracts normally.
In ventricular fibrillation , ventricles quiver, abnormal FAST ventricular depolarisation.
-many ectopic firing mn kl mukan> cause ventricles to rapidly work> NO CO>> cardiac arrest> DEAD
what causes ectopic firing?
..
what can abnormal rythems arise from?
- abnormal conduction
2-abnormal impulses
what is meant by Supraventricular rythems?
rythems that may arise above the ventricles!
- sinus node
- atrium
- Av node
label
it goes like this:
Atrial Tachycardia (120-250 bpm)
Atrial flutter (250-350 bpm)
Atrial Fibrillation (350-650 bpm)
what is meant by the “ventricular escape rythem?”
when the a pacemaker in the ventricles takes over!