Heart Rates
60-100
What is the intrinsic rate of the SA node?
0.12-0.20 seconds (3-5 small boxes)
What is a normal PR interval?
Indicates Atrial Contraction
Shape- Round and Smooth
Duration- < 0.11 sec
What is the P wave?
0.04 seconds
What is the size of one "small" box
The signal for the heart to beat comes from the SA node. Can be bradycardic, normal, or tachycardic
What are Sinus Rhythms?
Less than 60 bpm
What is Bradycardia?
less than 0.11 seconds (3 small boxes)
What is the P wave?
Represents Ventricular Depolarization
Normal width is 0.12 seconds (less than 3 small boxes)
What is the QRS complex?
0.20 seconds
What is the size of one "Large" box?
The signal for the heart to beat comes from the Ventricles
What are ventricular rhythms?
Rate 101-160
What is Sinus Tachycardia?
less than 0.12 sec. (3 small boxes)
What is the QRS complex?
Represents Ventricular Repolorization
Should be rounded or upright
Inverted or prominent t waves indicate underlying pathology for conditions affecting repolorization
What is the T wave?
30 large boxes
How many large boxes in a 6 second strip.
The signal for the heart to beat comes from the Atrium
What are atrial rhythms?
Rate 40-60
What is the rate of the AV Junction?
between 0.30 and 0.44 sec (8 to 11 small boxes)
What is a normal QT Interval?
Shows the complete VENTRICULAR Cycle
Normal values are between 0.30 and 0.44 (8-11 small boxes)
What is the QT interval?
5 mm or 0.5 millivolts
What is the height of one "large" box?
The signal for the heart to beat comes from the junctional tissue around the AV node
What are junctional rhythms?
Rate 20-40
What is the instrinsic rate of the ventricles (purkinje fibers) ?
Duration- > 0.08 sec.
Height- 1mm above or below the isoelectric line
What is a normal ST segment?
Starts from the end of the S wave when the deflection returns to baseline
Used for computers to be able to interpret S-T elevation
What is the J- point?
It is electrically neutral
Any deviation from this is called a wave
Isoelectric line or Baseline
Type of irregular heartbeat. Happens when your heart beats too soon.
What is an ectopic beat or ectopy?