ECG Flashcards
Intrinsic rate of the SA node
60-100 bpm
intrinsic rate of AV node
40-60 bpm
intrinsic rate of ventricles
25-40 bpm
What does the P wave represent
depolarization of both atria
What does the P-R interval represent
The electrical transmission from the atria to the ventricles
What does the QRS complex represent
ventricular depolarization
what does the S-T segment represent
early repolarization
What does the T wave represent
repolarization of the ventricles
3 methods to calculate HR
- 1500 method
- Cardiac ruler
- 6-second method
What is the 1500 method
- Calculate R-R interval
HR = 1500/# of squares
What is the cardiac ruler method
- each 5 mm block = 300
What is the 6-second method
- 6 seconds on strip is 30 5mm boxes
- Count number of RR intervals during 6-seconds
- Multiply by 10
what is sinus bradycardia
HR < 60 bpm
what is tachycardia
HR > 100 bpm
The more leads an ECG has, the more….
accurate
the more snapshots of the heart
What are the 6 steps to interpretation of 3 or 5 lead ECG
- calculate rate
- calculate rhythm
- examine the relationship between the P wave and the QRS complex
- Examine the PR interval
- Check for terrible triad of ischemia, injury, and infarction
- What are the hemodynamic consequences of this rhythm
How do you examine atrial rhythm
P-P intervals using pencil + paper
how do you examine atrial rhythm
R-R intervals using pencil + paper
What is a slightly irregular rhythm? Makedly?
< or equal to 0.04s
>0.04
What is the amplitude and duration of a normal p wave
amp: 2-3 mm high
duration: 0.06-0.12 s
What is the amplitude and duration of a QRS complex
- Amp: 5-30 mm
- Duration: 0.04-.11 s
Normal duration of PR interval
0.12-0.20 seconds
What does a peaked or enlarged P-wave indicate
atrial hypertrophy or enlargement associated with COPD, pulmonary emboli, vascular disease or heart failure
What does an inverted P wave indicate
reverse conduction from atriaventricular junction toward atria