453: Test 2 EKG | Flashcards

The heart is the engine of the body, it is_________ and___________.

Cardiac cells are electrically negative at rest. ____IN and_____OUT

Movement of sodium and potassium in and out of the cells cause changes that can be picked up on the ______ by electrodes and translated to the ECG printout.

When the cell is stimulated by an electrical impulse,________ rushes into the cell and____________ leaks out. This causes cell to become positively charged, this is referred to as_________! Contraction follows.

During cell recovery, the sodium-potassium pump returns cell to it’s negative charge. This is____________! Muscle relaxation follows.

#1 SA Node=___-__ beats per minute

#2 _____=40-60 BMP

#3____,_____, & _______=20-40 BPM

Cardiac Intervals
One small box=_____ seconds
One large box=_____ seconds
5 large boxes=_____ seconds

PR interval – time for electrical impulse to get from _______ to the _________, <0.20 seconds (5 small or 1 large boxes)

_____ interval – measures the time it takes to depolarize the ventricles, < 0.12 seconds (3 small boxes)

QT interval – measures depolarization and repolarization time of the ventricles. Measured from the beginning of the QRS to the end of the T-wave. Should be less than one half the R – R interval. If prolonged can lead to ____________. Usually 0.36 - 0.44 seconds (9 – 11 little boxes) Lead 2 or V5 – 6 best place to measure.

Indicates atrial depolarization, or contraction of the atrium.
The P wave can have any shape, up, down, or biphasic, as long as it is consistent

Indicates AV node conduction time
Duration time is 0.12 to 0.20 seconds

Indicates ventricular depolarization, or contraction of the ventricles.
Interval is .04-.10 seconds or <0.12 seconds

Indicated ventricular repolarization. Or the ventricles at rest
Rounded and asymmetrical

Questions to consider with an EKG