This episode is less about boards, more about being thorough and thinking about how to process an EKG systemically in order to not miss something. For boards, it’s ok to jump to what is glaring at you. No questions or take away points associated with this podcast.
As promised, here is my EKG Cheatsheet!
Evidence of a pacemaker?
Failure to capture
Heart doesn’t “capture” signal
Pacemaker spike, but no P wave
Failure to Pace/Oversensing
Pacemaker is over sensing electrical activity
HR is slow, pacemaker isn’t initiating beats
Failure to sense
Pacemaker ISN’T sensing natural heart activity
sends unnecessary spikes
EKG Interpretation
1 box=0.04s wide x 1mm high
Rate=how fast
6 second strip*10
can be used for regular or irregular rhythms
May also use 300-150-100-75-60-50 method
Refers to # of large boxes in between R waves
1 large box=300bpm, 2 large boxes=150bpm
Rhythm MUST be regular
Tachycardia is ALWAYS tachycardia (>100bpm)
regardless of sinus, junctional, or ventricular tachycardia
Sinus
Bradycardia >60
Normal 60-100bpm
Junctional
Escape 40-60bpm
Accelerated Junctional 60-100bpm
Ventricular
Idioventricular 20-40bpm
Accelerated Ventricular 40-100bpm
Rhythm=pattern
normal=atria, junction, ventricals
If no, we already know the rhythm is irregular
No?
Junctional rhythm?
inverted or absent p waves
normal QRS complex
non-compensatory pause
Ventricular rhythm?
absent p waves
wide-bizarre complex
pre-mature ventricular contraction with compensatory pause
A fib?
Yes? Does each P have a QRS?
No?
A flutter
2nd/3rd degree heart blocks
P wave
Normal=2.5×2.5 boxes
Represents atrial depolarization
Too wide? (3 boxes)
Left atrial enlargement
May also be M shaped
Left is LONG
Too tall? (3 boxes)
Right atrial enlargement
PR Interval
Normal= 0.12-0.2s (3-5 boxes)
Too long?
Consistent=1st degree heart block
Inconsistent= 2nd degree heart block (Type 1 or 2)
Too short? = Pre-Excitation Disorder
Wolf-Parkinson-White
Also has delta wave
Lown-Ganong-Levine
QRS Complex
Normal = less than 0.12s (3 boxes)
Too wide?
Bundle branch block
Left
Deep S in V1 (carrot)
Broad R in v6
Right
RsR’ in v1 (rabbit ears)
Wide S in v6
Ventricular rhythm
Wide, bizarre complex with no p wave
Height?
Right ventricular hypertrophy