Basic EKG (Exam #1)

Question 1

What is the ability to produce an electrical impulse without outside nerve stimulation?

Answer 1

Automaticity

Question 2

What is the ability to respond to electrical stimulus?

Answer 2

Excitability

Question 3

What is the ability to transmit electrical stimulus from cell-to-cell?

Answer 3

Conductivity

Question 4

What is ability to contract when electrically stimulated?

Answer 4

Contractibility

Question 5

What phase of the cardiac cycle does systole correlate with? Diastole?

Answer 5

• Systole = contraction

- Diastole = relaxation

Question 6

What ANS system is the cardioaccelerator, and what NT(s) is released?

Answer 6

Sympathetic

- Adrenergic (NE, Epi)

Question 7

What ANS system is the cardioinhibitor, and what NT(s) is released (via what)?

Answer 7

Parasympathetic

- Cholinergic (ACh) via Vagus n.

Question 8

What is the intrinsic rate of the SA Node, and what is another name for this? What ion drives the SA node?

Answer 8

Primary Pacemaker

• IR: 60-100 bpm
• Na driven

Question 9

What is the intrinsic rate of the AV Node, and what is another name for this? What ion drives the AV node?

Answer 9

“Gatekeeper”

• IR: 40-60 bpm
• Ca driven

Question 10

What is the intrinsic rate of the Purkinje fibers? When would this take over as pacemaker?

Answer 10

20-40 bpm

- Becomes pacemaker if SA & AV nodes fail

Question 11

With resting state, what is the polar state is the cell in and what does this mean for ion movement?

Answer 11

Resting = Polarization

- NO net ion flow

Question 12

With an action potential, what is the polar state is the cell in and what does this mean for ion movement?

Answer 12

AP = Depolarization

- Na enters cell and interior becomes positively charged

Question 13

With repolarization, what does this mean for ion movement?

Answer 13

Na, Ca and K leave cell and interior returns to negatively charged resting state

Question 14

What does bipolar lead mean, and what are the three bipolar leads?

Answer 14

Opposite polarity (- AND +)
- Standard (I-III)

Question 15

What does unipolar lead mean, and what are the nine unipolar leads?

Answer 15

ONLY +

• Chest/Precordial Leads (V1-V6)
• Augmented Limb Leads (aVR, aVL, aVF)

Question 16

What part of the cardiac cycle does the P wave represent?

Answer 16

Atrial depolarization

Question 17

What part of the cardiac cycle does the QRS complex represent? What other part is hidden in this complex?

Answer 17

Ventricular depolarization

- Also, atrial repolarization = hidden

Question 18

What part of the cardiac cycle does the T wave represent?

Answer 18

Ventricular repolarization

Question 19

What are the six LIMB leads, and what plane view do they make up? What is another name for this?

Answer 19

FRONTAL plane = Einthoven’s Triangle

• Standard (I-III)
• Augmented (aVR, aVL, aVF)

Question 20

What are the six CHEST/Precordial leads, and what plane view do they make up?

Answer 20

HORIZONTAL plane

- V1-V6

Question 21

Movement TOWARD ___ will appear ___ the baseline on the EKG pacing?

Answer 21

Toward positive electrode = ABOVE baseline

Question 22

Movement AWAY from ___ will appear ___ the baseline on the EKG pacing?

Answer 22

Away from positive electrode = BELOW baseline

- Or toward negative electrode