Card Set Information
Bundle of His
Electrical impulses cause the heart to
depolarize as the heart chambers contract
Bundle of His: Paces
relaxation, return to normal resting stage of the cell
The SA node is the
Similar to “pebble dropped in water” sending ripple effects starting with atria contraction
Time when atrium is contracting
Impulse travel through the conduction system
impulse is traveling through the conduction
After the electrical activity passes through the AV node, bundle branches and Purkinje Fibers then depolarization of the ventricles occur
The filaments of the Purkinje fibers distribute the depolarization stimulus to the ventricular myocardial cells
Depolarization of the ventricles produces the QRS complex
Measured from the beginning of the Q Wave until the end of the S wave.
First downward deflection
Not always present
Follow R wave
Should return to baseline
Represent early ventricular repolarization
Normally isoelectric line
ST elevations or depression can be caused by
myocardial injury, ischemia, infarction etc.
T wave tells whether you are having an
Low broad hump
Rapid phase of ventricular repolarization
Repolarization of the ventricles begin immediately after the QRS complex and persists until the end of the T wave
Interference seem on rhythm strip or monitor
Looks like fuzzy baseline
Caused by patient moving, loose electrodes,
Can mimic lethal rhythms – check patient!
Can look like an arrythmia. Chieck pt if , if pt is
stable could be leads or pt is moving
EKG tracing paper
Each smallest block is 1mm by 1mm
Each small block is 0.04 sec.
Between the heavy black lines are 5 small squares totaling 0.2sec.
Usually from R wave to R wave
-“big block method” – most accurate
-“6 second strip” – quick method least accurate
What does th p wave in an ECG represent