Normal ECG Flashcards
P wave
Atrial depolarization
In what leads is the P wave upright?
1, 2, AVF, V4, V5, V6
In what leads is the P wave inverted?
AVR
PR Interval
From the beginning of the P wave to the beginning of the QRS complex
What does the PR interval represent?
Time from the SA node to the ventricular myocyte
Normally, the PR interval should be less than?
0.2 seconds
Each little box on an ECG represents ____ mm and ____ seconds
1 mm
0.04 seconds
Each bigger box (dark line to dark line) on an ECG represents _____ mm and ____ seconds
5 mm
0.20 seconds
QRS complex
Ventricular depolarization
The QRS complex should be less than ___ seconds
0.10
Q waves should be less than ____ seconds in width
0.03
ST segment takes place after?
QRS complex
Normally, the ST segment is?
Isoelectric (baseline)
The ST segment is NEVER normally depressed more than ___ mm
1/2
If the ST segment is elevated more than ___ mm, it could indicate subepicardial ischemia
1-2
If the ST segment is depressed more than 1/2 mm, it could indicate?
Subendocardial ischemia
T wave
Ventricular repolarization
In what leads is the T wave upright?
1, 2, V3 - V6
In what leads is the T wave inverted?
AVR
In standard leads, the T wave should not be taller than?
5 mm
In precordial leads, the T wave should not be taller than?
10 mm
QT interval
Ventricular systole
