Cardiac function measurements

Question 1

What is a doppler electrocardiography?

Answer 1

Measures and visualizes the speed and direction of blood flow

• Red= hot=towards
• Blue= cold= away from

Question 2

What is a normal ejection fraction?

Answer 2

55% and above

Question 3

Increase or decrease in contractibility leads to downward shift of ESPVR line? Name a cause

Answer 3

Decreased contractibility causes by heart disease

Question 4

How would a vasoconstrictor affect the ESPVR line?

Answer 4

increases after load and thus increase contractibility

Question 5

What is Fick’s principle?

Answer 5

Calculates the rate at which a substance is being added to or removed from the blood as it passes through an organ

Question 6

What is the most accurate measurement of CO? What else is this good for?

Answer 6

Using Fick’s Principle
Q= Xtc/(Xa-Xv)

Tissue metabolism as well

Question 7

What is a cardiac index?

Answer 7

Cardiac output/Body surface area

- use the Namogram scale using weight and height

Question 8

What does the P wave represent?

Answer 8

Atrial depolarization

Question 9

What does the flat line between the P wave and QRS complex mean?

Answer 9

Pause that allows the ventricles to fill

Question 10

What is the QRS complex represent?

Answer 10

Ventricular depolarization

Question 11

What does the ST segment represent? What is responsible for this?

Answer 11

Plateau phase of ventricular AP

- Ca2+

Question 12

What does the PR interval represent?

Answer 12

Conduction time through the atria and AV node

Question 13

What does the QT interval represent?

Answer 13

Total time of ventricular systole

Question 14

What do the smallest boxes on an EKG represent in time?

Answer 14

0.04 seconds

Question 15

What does 1 large box represent?

Answer 15

0.2 seconds

Question 16

In Einthoven’s Triangle where are the leads?

Answer 16

RA- both neg
LA- One neg one positive
LL- Both pos

Question 17

Where are leads 1,2 and 3?

Answer 17

1. RA to LA
2. RA to LL
3. LA to LL

Question 18

What doe positive and negative inflections of the EKG represent?

Answer 18

1. pos- moving toward a positive charge

2. moving away from a pos charge

Question 19

Where does the depolarization begin of the QRS complex?

Answer 19

Left intra-ventricular septum

Question 20

Why does the T wave a repolarization effect have a positive inflection on EKG?

Answer 20

Negative wavefront moving away from positive charge (towards negative). Thus double negative making a positive wave form

Question 21

What is the mean electrical axis?

Answer 21

The orientation of the Cardiac dipole during the most intense phase of ventricular depolarization

Question 22

What are normal, left and right axis deviations?

Answer 22

-30-90 degrees= normal

90= right axis deviation

Question 23

Which lead should have the largest R wave?

Answer 23

Lead 2

Question 24

What are Augmented leads?

Answer 24

For 6 lead EKG

- Named for the physical location on the body voltage recording the + pole

Question 25

What are aVR,aVL and aVF? What are their perpendiculars?

Answer 25

aVR- Starts RA and 3
aVL- Start LA and 2
aVF- Start LL and 1

Question 26

What are the degrees of the a 6 lead EKG?

Answer 26

1. 0
2. 60
3. 120
   aVR. -150
   aVL. -30
   aVF. 90

Question 27

How does one calculate the mean electrical axis?

Answer 27

1. Calculate by finding largest R wave and this is your dipole. If wave is negative then its 180 degrees of dipole
2. Determine lead that is most equiphasic QRS complex. Which lead is 90 degrees away from that

Question 28

What is the limit of the 6 lead EKG? What solves this?

Answer 28

6 lead is 2d. If you want 3d view you need a 12 lead.

Question 29

What are the additional leads of the 12 lead called?

Answer 29

Precordial unipolar leads to view transverse plane

v1-v6