ECG Flashcards
atrial depolarization is represented where
PQRST
P wave
ventricular depolarization is represented where
PQRST
QRS wave
ventricular repolarization is represented where
PQRST
t wave
conduction time from the SA node through the atria and av node is represented where
PQRST
PR interval (PQ interval)
conduction time through the ventricular system is represented where
PQRST
QRS interval
entire ventricular system is depolarizes(no dipole; thus isoelectric line) is represented where
PQRST
ST segment
electrical systole of the ventricles is represented where
PQRST
QT interval
the origin of the ECG signal is caused by what?
small extracellular signals produced by the movement of AP through cardiac myocytes
why is there no electrical activity in the PR segment?
the electrical activity is small and not detectable with the ecg
the ECG bipolar lead uses two electrodes (pos and neg) to measure the ___________________between the electrodes
the ECG bipolar lead uses two electrodes (pos and neg) to measure the difference in extracellular charge (ie, dipole) between the electrodes
upward or downward deflection of an ecg wave depends on the charge nearest the _____ ______
pos. electrode
depolarization proceeding toward the positive electrode in a lead will produce _______ deflection.
depolarization proceeding toward the positive electrode in a lead will produce upward deflection.
depolarization proceeding away from the positive electrode in a lead will produce _______ deflection.
depolarization proceeding away from the positive electrode in a lead will produce downward deflection.
I regards to standard ECG limb leads;
the left arm, lead 1 polarity would be ?
positive
In regards to standard ECG limb leads;
the right arm, lead 1 polarity would be ?
negative
I regards to standard ECG limb leads;
the left arm, lead 3 would be what polarity?
negative
In regards to standard ECG limb leads;
the right arm lead 2 would be what polarity
negative
as the depolarization wave spreads form SA node to the ventricles, it creates _____dipoles
extracellular
the net dipole or mean axis is?
the sum of all the individual diploes at any given moment
the mean axis would ____ _____ from the infarcted area
veer away or veer towards
veer away
right ventricle hypertrophy would cause a right axis deviation. What condition could cause this?
4
right ventricle hypertrophy would cause a right axis deviation. What condition could cause this?
- pulm hypertension
- mitral stenosis
- congenital heart disease
- pulmonary embolism
what are 3 things that could physically displace the heart causing a left or right axis deviation? How would the deviation correlate
- pnuemo
- copd
- congenital defect, dextrocardia
deviation on axis correlates with the heart deviation
The polarity of what two leads is used to determine the quadrant of the mean electrical axis?
lead 1
aVF
lead 2 positive deflection(upward) in left axis deviations indicates physiological deviation or pathological?
positive(upward) denotes physiological such as enlarged runners heart
lead 2 negative deflection(downward) in left axis deviations indicates physiological deviation or pathological?
downward denotes pathological deviation
what is the normal left axis degrees on Gaffin’s slides?
-90 to 0
0 to 90
90-180
180- -90
0 to 90
if lead one has a positive inflection and aVF a negative, which axis shift?
left axis shift
