CH 26 DYSRHYTHMIAS AND CONDUCTION PROBLEMS Flashcards
What is sinus bradycardia
An impulse that originates in the SA node at a slow rate.
What is conduction
The electrical impulse that travels from the SA node thru the atria to the AV node
Systole
The contraction of the ventricles
Diastole
The ventricles relaxing
Artifact
Distorted, irrelevant ECG waveforms, can be caused by chest hair impeding the electrodes from detecting the electrical cure t of the heart.
What does a standard 12 lead ECG reflect
The electrical activity primarily in the left ventricle
Positive deflection
When an ECG waveform moves toward the top of the paper
Negative deflection
When an ECG waveform moves toward the bottom of the paper
U wave
Is thought to represent REPOLARIZATION of the Purkinje fibers
This wave is rare and is sometimes seen in ppl with hypokalemia,HTN or heart disease. The U wave is generally smaller than the T wave.
PR INTERVAL
Is measured from the beginning of the P wave to the beginning of the QRS complex.
ST SEGMENT
Represents early ventricular repolarization
It last from the end of the QRS complex to the beginning of the T wave.
QT interval
Represents the total time of ventricular depolarization and repolarization.
It is measured from the beginning of the QRS complex to the end of the T wave.
The QT INTERVAL varies under what circumstances
HR, gender and age.
If the QT interval is prolonged, what does this suggest
The patient may be at risk for a LETHAL ventricular dysrhythmia called Torsades de pointes
TP interval
Is measured from the end of the T wave to the beginning of the next P wave
The PP interval
Is measured from the beginning of 1 P wave to the beginning of the next P wave.
What is the PP interval used to determine
The atrial rate and rhythm
RR interval is measures how
From one QRS complex to the next QRS complex
What is the RR complex used to determine
It is used to determine ventricular rate and rhythm
How do you determine and calculate HR on a ECG strip
Count the # of small boxes between the RR interval and divide 1500 by that #
Ex: 10 small boxes between RR intervals= 1500/10= 150 bpm
What is another alternative for calculating a HR on a ECG strip
Count the # of RR intervals in a 6 second strip and multiply that # by 10.
How do u calculate 3 seconds on a ECG strip
Count 15 BIG BOXES
How do you determine the atrial rate on a ECG paper
Use the PP interval instead of the RR interval
What does each small box on ECG paper represent
0.04 seconds
If the RR interval or or PP interval is less than 0.8 seconds, what does that mean
The rate is regular…. If the intervals are different, the rates are called irregular
