ECG

Question 1

atrial depolarization is represented where
PQRST

Answer 1

P wave

Question 2

ventricular depolarization is represented where
PQRST

Answer 2

QRS wave

Question 3

ventricular repolarization is represented where
PQRST

Answer 3

t wave

Question 4

conduction time from the SA node through the atria and av node is represented where

PQRST

Answer 4

PR interval (PQ interval)

Question 5

conduction time through the ventricular system is represented where
PQRST

Answer 5

QRS interval

Question 6

entire ventricular system is depolarizes(no dipole; thus isoelectric line) is represented where
PQRST

Answer 6

ST segment

Question 7

electrical systole of the ventricles is represented where
PQRST

Answer 7

QT interval

Question 8

the origin of the ECG signal is caused by what?

Answer 8

small extracellular signals produced by the movement of AP through cardiac myocytes

Question 9

why is there no electrical activity in the PR segment?

Answer 9

the electrical activity is small and not detectable with the ecg

Question 10

the ECG bipolar lead uses two electrodes (pos and neg) to measure the ___________________between the electrodes

Answer 10

the ECG bipolar lead uses two electrodes (pos and neg) to measure the difference in extracellular charge (ie, dipole) between the electrodes

Question 11

upward or downward deflection of an ecg wave depends on the charge nearest the _____ ______

Answer 11

pos. electrode

Question 12

depolarization proceeding toward the positive electrode in a lead will produce _______ deflection.

Answer 12

depolarization proceeding toward the positive electrode in a lead will produce upward deflection.

Question 13

depolarization proceeding away from the positive electrode in a lead will produce _______ deflection.

Answer 13

depolarization proceeding away from the positive electrode in a lead will produce downward deflection.

Question 14

I regards to standard ECG limb leads;

the left arm, lead 1 polarity would be ?

Answer 14

positive

Question 15

In regards to standard ECG limb leads;

the right arm, lead 1 polarity would be ?

Answer 15

negative

Question 16

I regards to standard ECG limb leads;

the left arm, lead 3 would be what polarity?

Answer 16

negative

Question 17

In regards to standard ECG limb leads;

the right arm lead 2 would be what polarity

Answer 17

negative

Question 18

as the depolarization wave spreads form SA node to the ventricles, it creates _____dipoles

Answer 18

extracellular

Question 19

the net dipole or mean axis is?

Answer 19

the sum of all the individual diploes at any given moment

Question 20

the mean axis would ____ _____ from the infarcted area

veer away or veer towards

Answer 20

veer away

Question 21

right ventricle hypertrophy would cause a right axis deviation. What condition could cause this?

4

Answer 21

right ventricle hypertrophy would cause a right axis deviation. What condition could cause this?

1. pulm hypertension
2. mitral stenosis
3. congenital heart disease
4. pulmonary embolism

Question 22

what are 3 things that could physically displace the heart causing a left or right axis deviation? How would the deviation correlate

Answer 22

1. pnuemo
2. copd
3. congenital defect, dextrocardia

deviation on axis correlates with the heart deviation

Question 23

The polarity of what two leads is used to determine the quadrant of the mean electrical axis?

Answer 23

lead 1

aVF

Question 24

lead 2 positive deflection(upward) in left axis deviations indicates physiological deviation or pathological?

Answer 24

positive(upward) denotes physiological such as enlarged runners heart

Question 25

lead 2 negative deflection(downward) in left axis deviations indicates physiological deviation or pathological?

Answer 25

downward denotes pathological deviation

Question 26

what is the normal left axis degrees on Gaffin’s slides?

-90 to 0

0 to 90

90-180

180- -90

Answer 26

0 to 90

Question 27

if lead one has a positive inflection and aVF a negative, which axis shift?

Answer 27

left axis shift