noninvasive ECG

bipolar limb leads

LI, LII, LIII

LI =

LA - RA

LII =

LL - RA

LIII =

LL - LA

LI + LIII =

LII

unipolar limbleads

aVr, aVI, aVf

aVr

Augmented Right Arm Lead; determine SR

aVI

anterior wall lead

aVf

inferior wall lead

which lead should be opposite of LII?

aVr

which direction is the spread of depolarization in LIII, if the p wave is displays a positive deflection?

towards the left leg

six precordial (chest) leads

V1, V2, V3, V4, V5, V6; unipolar & horizontal plane

V-1

4 RICS, RSB - septal

V-2

4 LICS, LSB - septal

V-3

between V-2 and V-4 - anterior

V-4

5 LICS, mid-clavicular - anterior

V-5

5 LICS, AAL - lateral

V-6

5 LICS, MAL - lateral

T OR F: The right leg normally acts as a ground to prevent interference when recording an ECG.

true

In an individual with normal conduction, the direction of depolarization is _________ to ___________ in Lead I.

RA , LA

T OR F: When placing an electrode, you should place it over the breast tissue.

false

a _______ wave will appear if the depolarization wave is traveling toward the positive pole

positive

a _______ wave will appear if the depolarization wave is traveling toward the negative pole

negative

when the path of depolarization is _______, it is traveling at a 90 degree angle

biphasic

anterior wall limb leads

LI and aVI

inferior wall limb leads

LII, LIII and aVf

scalar electrogardiography

clinical electrocardiography; 2D; time and amplitude are recorded and measured

time

width & duration

amplitude

voltage

current

the flow of electrical impulses

voltage

the strength of the current (potentials)

electrode

metal plates that pick up the charge on the surface of the body (sensors -- picking up potentials)

lead

records & displays the electric potential between two or three electrodes

bipolar lead

having two poles - one positive & one negative

unipolar lead

having one positive pole in relation to a zero potential

precordial leads

siz horizontal chest leads placed on anterior chest wall

isolectric

amplitude neither positive or negative; line is the flat line on ECG

heart rate

the number of cardiac cycles per minute

sinus bradycardia

<60 bpm

sinus tachycardia

>100 bpm

Depolarization relates to ____________ and repolarization relates to ________________

activation, recovery

T OR F: When a large area of muscle mass is depolarized the potentials will normally be increased on the ECG graph paper, in comparison to a smaller muscle mass being activated

true

Which of the following ECG intervals indicates ventricular depolarization and ventricular repolarization?

QT interval

On the ECG paper, one large box represents ___________seconds

0

On the ECG paper, how many small boxes are within one large box?

25

On the ECG paper, what is the amplitude of 10 mm if the ECG machine is standardized in the normal fashion?

1 mV

The normal P wave width duration is less than:

0.12 seconds

An ECG deflection which is partly positive or negative is called:

biphasic

The normal PR interval is:

0.12-0.20 seconds

The negative wave immediately following the ECG R wave is called the

S wave

the normal maximal QRS duration is

0.10/0.11 seconds

The junction between the end of the ORS complex and the ST segment is termed the

J point

The normal length of the ST segment is

not measured

A ST segment may vary but normal deviation is within

1mm of the isoelectric line

the ECG will record _______ events

electrical

P wave

atrial depolarization

QRS complex

ventricular depolarization

ST segment

early ventricular repolarization

T wave

ventricular repolarization

U wave

late ventricular repolarization