Reading an EKG Flashcards
How long is each little box on an EKG?
.04 seconds (40ms)
How long is each big box on an EKG?
5 little boxes
.2 seconds (200ms)
How is the PR interval measured?
From onset of P wave to onset of QRS
How long is a normal PR interval?
120-200ms
3-4 boxes
How long is a normal QRS complex?
80-120ms
2-3 boxes
What would a narrow QRS indicate?
Atrial or junctional arrhythmias
What would a wide QRS indicate?
Ventricular
What does an elevated ST segment indicate?
Myocardial Ischemia
What does a depressed ST segment indicate?
Subendocardial infarction
What does an upside T wave indicate?
Acute Ischemia
What is a normal sinus rhythm?
P wave before each QRS
QRS after each P wave
What does a long PR interval indicate?
1st degree AV block
What is a bigeminal pattern? Trigeminal?
Two quick beats then a rest
Three quick beats then a rest
What would atrial flutter look like?
A regular set P wave:QRS complex ratio
P waves are same monomorphic
What would A fib look like?
An irregular heart rate
Random polymorphic P waves
There DOES NOT have to be lots of P waves
What would have wide upside-down complexes?
V Tach
What would V fib look like?
Irregular rate and rhythm
No set pattern (unlike torsades)
What are random wide QRS complexes called?
PVCs
What would an irregular junctional rhythm look like?
Bradycardia
P wave after a narrow complex
What is a flatline called?
Asystole
What has progressively longer PR intervals and eventually has a P without a QRS complex?
2nd degree AV block type 1; AKA
Mobitz 1 or Wenckebach
What is a Mobitz 2 or 2nd degree AV block type 2?
Randomly does not conduct
What has rhythmic P waves, rhythmic R waves, but non-synchronized P/QRS?
3rd degree conduction block
What do the QRS complexes look like with a 3rd degree block?
Wide
Upside down
What is a V tach preceded by a prolonged QT that has a sinusoidal amplitude?
Torsades de pointes
What is the axis of a patient with a positive I and a positive aVF?
Normal
What is needed for a patient with a positive I and a negative aVF to be considered normal?
A positive II
A patient has a positive I, negative II, and negative aVF?
Left Axial Deviation (LAD)
What is needed for a Right Axial Deviation (RAD)?
Negative I
Positive aVF
What is looked at when considering atrial hypertrophy?
P waves
What does the v1 R wave > S wave tell us?
Right Ventricular Hypertrophy (RVH)
Normally minimal R wave with deep S wave
What does a v6 R wave + v1 S wave > 35mm indicate? Or v5 R wave + v2 S wave > 35mm
Left Ventricular Hypertrophy (LVH)
What is a difference between Left Atrial Enlargement (LAE) and Right Atrial Enlargement (RAE)?
LAE has a long P wave duration
RAE has a tall/peaked P wave
How does an acute/recent infarct present?
ST elevation with significant (pathologic) Q waves
Inferior wall ischemia has elevated ST segments in which leads?
II
III
aVF
Elevated ST segments in V1 and V2 indicates an ischemia where?
Anterior septum
Elevated ST segments in V5 and V6 indicates an ischemia where?
Lateral wall
