Dr. Lorenzo Lecture 3 EKG Flashcards
What does the P wave represent?
Atriall depolarization
What does the QRS complex show? What does it look like?
Ventricular Depolarization
-largest wave
What does the T wave represent?
Ventricular repolarization
Why don’t we see atrial repolarization?
It is taken over by the QRS complex, we just can’t see it on the EKG.
What is the A-V nodal delay?
P-Q or P-R interval- time between beginning of atrial contraction and beginning of ventricular contraction.
What is the ST segment?
ventricular systole
What is the Q-T interval?
Approximates the time of ventricular contraction
What is the interval used to estimate heart rate?
R-R interval
If the R-R interval is 0.80 seconds, what is the heart rate?
(60 second/minute)/0.8= 75 beats per minute
Where is the ‘ground’ lead placed?
Right hip
Taking Einthoven’s Law into account; what would Lead II mV be if Lead I=1.0 mV and Lead III= 0.5 mV?
1.0+0.5=1.5 mV
What would indicate an MI on an ECG?
Acute MI: ST segment elevation
Post-MI (chronic): enlarged Q waves & ST segment depression
What are the 3 degrees of heart block?
1st: prolonged P-R interval
2nd: P-R interval increases until “dropped beat”
3rd: Complete A-V block
What are the two types of the 2nd degree heart block?
Type 1: progressive prolongation of P-R interval (AV node abnormality)
Type 2: fixed number of non conducted P waves for every QRS complex such as 2:1, 3:1 or 3:2 (His-Purkinje abnormality)
What is a distinct characteristic of HYPOkalemia on an EKG?
presence of U wave
