Normal EKGs Flashcards
In which leads is the P wave upright?
1, 2, V4-6 and AVF
In which lead is the P wave inverted in?
AVR
In which leads will the P wave be variable?
3, AVL and other chest leads
What is the PR interval?
Beginning of P wave to beginning of QRS complex
What is the normal time from SA node to ventricular muscle fiber (PR interval)?
.12-.20 seconds
Describe the QRS complex
Ventricular depolarization
0.05-0.10 seconds
Q wave shouldn’t be more than 0.03 sec in width
1-2mm is normal for the QRS complex in which leads?
1, AVL, AVF, V5 and V6
Describe the ST segment
Normally isoelectric
Normally elevated not more than 1mm in standard leads and 2mm in chest leads
Never normally depressed more than 1/2 mm
What is an ST segment depression indicative of?
Subendocardial
What is an ST segment elevation indicative of?
Subepicardial or transmural injury or ischemia
The T wave is upright in which leads?
1, 2, V3-6
The T wave is inverted in which leads?
AVR
The T wave is variable in which leads?
3, AVL, AVF, V1-2
What is the shape of the T wave?
Slightly rounded and asymmetrical
What is the height of the T wave?
Not greater than 5mm in standard leads
Not greater than 10mm in precordial leads
What is the QT duration (interval)?
Length of ventricular systole
Variations of the QT interval can be indicative of which pathologies?
Myocardial ischemia, injury or infarction
An ischemic pattern is associated with what?
Inverted T waves
Tall upright T waves are indicative of what?
Hyperkalemia
U wave is indicative of what?
Hypokalemia
If there is no AV block how long should the PR interval be?
<0.2 seconds
If there is no bundle branch block how long should the QRS complex be?
<0.12 seconds
How can you tell when there is sinus rhythm?
Is there a p wave before every QRS complex and vice versa?
What are the best leads for reading P waves?
Leads II and V1
