EKG Flashcards
The basics- what do we check every time?
Rate
Rhythm
Axis
Hypertrophy
Infarction
Wave interval and segment abnormalities
Waves and Segments
Waves - Summation Vectors
P, Q, R, S, T, U
Segments
ST
Intervals
PR less than 0.2 seconds (one big – five little boxes)
QRS less than 0.12 seconds (three little boxes)
QT 0.44 seconds Bazett’s formula
Rate
300, 150, 100, 75, 60, 50
Six second strip - Multiply by 10
(where the leads break is 3 seconds)
Leads
Lead I- across chest,
Lead 2- down across the heart, “physiologic lead”
Lead 3-
AVF - straight down
V leads- what plane?
horizontal
QRS Sequence of Ventricular Depolarization
Depolarization starts at the ventricular septum (Q wave) and the endocardial surfaces.
Average current flows from the base of the heart to the apex (R wave).
At the end of depolarization, the current reverses, flows toward the outer walls of the ventricles near the base (S wave).
Atrial rhythm
Up right P waves, narrow QRS
Junctional rhythm
Absent or inverted P waves, narrow QRS
Ventricular rhythm
No p waves
Wide QRS complexes
Repetitive sequence rhythms
Bigeminal, Trigeminal, Quadrigeminal
A series-pattern of ectopic depolarizations, either atrial or ventricular in origin
Automaticity issues
Escape beats with refractory periods
premature beats- irritable focus, reentry
Supraventricular rhythms with narrow QRS complexes
Sinus/ Atrial
Junctional
Wolf-Parkinson-White (WPW)
Sinus/Atrial
rhythm
Sinus arrhythmia
Wandering pacemaker, multifocal atrial tachycardia (MAT)
Paroxysmal atrial tachycardia (PAT)
Artial flutter- Singular atrial focus – reentry mechanism
Artial fib- Lack of any organized atrial activity
Junctional rhythms
Paroxysmal junctional tachycardia (PJT)
AV nodal reentry