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
* 1. Should be able to march caliper along R-R intervals without adjustments

* If no, we already know the rhythm is irregular


* 2.  Do we have distinct P waves?

* 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






* 3. Determine if regularly irregular or irregularly irregular.


* 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