ECG II Flashcards
What are the 3 things we can get from the EKG?
RatePerfusionRhythm
What is the A-H interval?
Time from initial rapid deflection of atrial wave to initial rapid deflection of his bundle potential
What does the A-H interval tell us?
It approximates the conduction time through the a-v nodeNORMAL: 50 - 120 msec
What does the H-V interval?
Time from initial deflection of his bundle potential and the onset of ventricular activity NORMAL : 35 - 45 msec
What are some variables that effect ECG?
Cardiac generator (site of depolarization)Cardiac electrical fields (tissue that surrounds heart)Body surface potentials (Leads, amplifiers, displays)ECG recording and interpretation
Einthoven’s Triangle is also known as what?
Axis of Acquisition
Lead I is what?
RA (-) ——-> LA (+)
When a wave of depolarization goes from - to +, this portrays what on the ECG waveform?
Upward slope / positive deflection
RA (-) ———> LL (+)
Lead II
Lead III?
LA (-) ———-> LL(+)
Electrical impulses that travel perpendicular to the lead axis show what on the ECG waveform?
Equiphasic deflection (half up and half down)orStraight line recording
Electrical impulses that travel away from the positive electrode show what on the ECG waveform?
Negative deflection
Which lead is the horizontal lead of the triangle?
Lead I
According to the triaxial reference system, what degrees are associated with Lead I?
0 and 180
According to the triaxial reference system, Lead II is associated with what degrees?
+60 and -120
According to the triaxial reference system, what degrees are associated with Lead III?
+120 and -60
For ventricular activity, a downward stroke (negative deflection) could represent which waves?
Q or S wave
What would an upward stroke for ventricular activity represent?
R wave
LOOK AT the DRAWINGS from powerpoint to get better idea of pics
I’m doing my best trying to make questions from them but proving difficultJUST REMEMBER I AM ASKING QUESTIONS REGARDING LEAD II
The start of the P-wave to p-wave peak represents what?
S-A node to A-V node atrial depolarization
The delay of the A-V node is showed by what of ECG waveform?
P-wave peaking to return to baseline
The Q waves negative deflection represents what?
Septal depolarization
Apical and L ventricular depolarization are shown as what on ECG waveform?
End of Q wave to peak of R wave
What begins the downward deflection of the R wave?
Late L ventricular depolarization
The T wave is shown because of what ?
Ventricular repolarization