Study Guide Flashcards
What are the intrinsic cardiac Pacemakers and their rates?
- SA node (intrinsic rate 60-100)
- AV node (Intrinsic rate 40-60)
- Bundle branches (Intrinsic rate (20-40)
What is the SA nodes intrinsic rate?
60-100 BPM
What is the AV nodes intrinsic rate?
40-60 BPM
What is the intrinsic rate of the Bundle branches?
20-40 BPM
What is the normal path of cardiac conduction?
- Originates in the SA Node
- AV Node causing atrial depolarization
- AV Node slightly delays impulse
- Bundle of HIS
- Bundle Branches
- Purkinje Fibers causing ventricular depolarization
What part of the EKG represents the absence of electrical activity/base line?
The Isoelectric Line
What does the P-Wave represent?
atrial depolarization
What does the QRS complex represent?
ventricular depolarization
What do the ST segment and T-Wave represent?
ventricular repolarization
hat part of the EKG represents the absolute and relative refractory periods?
1) QRS to peak of T-wave
2) the rest of the T-wave
Which part of the ECG represents ventricular depol and repol?
QT Interval
What is the normal length of the QT Interval?
- normally less than half the length of the R-R interval
- 360 - 440 ms
The small box of the ECG measures how many seconds?
0.04 secs along the horizontal axis
The small box of the ECG measures how many mV?
1 mV along the vertical axis
The large box of the ECG measures how many seconds?
0.20 secs along the horizontal axis
How many small boxes make up one large box on an ECG strip?
5 small = 1 large box
A six second strip has how many large boxes?
30 boxes
Five big boxes is how many seconds?
1 sec
How do you measure the PRI and what its the normal length?
- beginning of the P-wave to the beginning of the QRS complex
- normal = 0.12-0.20 secs or 3-5 sm boxes
What is the normal length of the QRS complex?
0.04 - 0.10 secs or 1-2.5 sm boxes
How do you calculate the HR on an irregular rhythm on an ECG?
count the # of P and R waves in a six second strip and x10
What is the 1500 rule for calculating the HR on an ECG?
- 1500 / # of small boxes b/t two consecutive P or R-waves
What is the 300 rule for calculating the HR on an ECG?
- 300 / # of large boxes b/t two consecutive P or R-waves
How do you calculate the HR on an ECG using the standard rule?
- use for regular rhythms only
- count and label 6 consecutive lg boxes
- 1 = 300
- 2 = 150
- 3 = 100
- 4 = 75
- 5 = 60
- 6 = 50
Criteria for NSR?
Impulse starts in SA node Rate: A and V = 60-100 Rhythm: A and V regular P-Wave: normal, 1:1 P-QRS PRI: 0.12 - 0.20 secs QRS: 0.04 - 0.10 secs
Criteria for Sinus Bradycardia?
Impulse starts in SA node Rate: A and V = < 60 Rhythm: A and V regular P-Wave: normal, 1:1 P-QRS PRI: 0.12 - 0.20 secs QRS: 0.04 - 0.10 secs
Criteria for Sinus Tachycardia?
Impulse starts in SA node Rate: A and V = 100 - 150 Rhythm: A and V regular P-Wave: normal, 1:1 P-QRS PRI: 0.12 - 0.20 secs QRS: 0.04 - 0.10 secs