Basic EP

Question 1

The flow of electric current is measured in:

Answer 1

Amperes, Amps = 1 coulomb/sec

Question 2

What is the term used to denote the total opposition to flow of alternating current in a circuit:

Answer 2

Impedance or resistance (ohms)

Question 3

Impedance

Answer 3

• term used to denote opposition to DC current flow

- changes with the frequency, amount of capacitance, resistance, and inductance

Question 4

What is the most common DC electric power source?

Answer 4

Battery

Question 5

DC current

Answer 5

• only travels in one direction

- flows steadily from - to +

Question 6

Electric battery current has a frequency of:

Answer 6

0 Hz

Question 7

The elimination of vibrations at certain frequencies is accomplished through the use of electronic devices known as:

Answer 7

filters

Question 8

ECG amplifiers

Answer 8

• incorporate a band pass filter

- cuts off low frequencies <0.1 Hz and high frequencies >100 Hz

Question 9

When a DC defibrillator “charges” it stores electrical energy in its:

Answer 9

Capacitors

Question 10

EP lab external defibrillators should be tested by

Answer 10

Discharging paddles into a dummy load

Question 11

Patient accidentally shocked on his T wave could cause

Answer 11

VF

Question 12

The watt second (or joule) is a unit of

Answer 12

• energy

- 1 Watt = 1 volt x 1 amp

Question 13

Defibrillator charge

Answer 13

50-360 joules

Question 14

Frequency units

Answer 14

Hz = cycles/sec

Question 15

Force units

Answer 15

Newton = m*kg/sec^2

Question 16

Energy or work units

Answer 16

joule = m^2kg/sec^2

also Ergs or Watt Sec

Question 17

Power units

Answer 17

Watt = m^2kg/sec^3 (also rate of doing work)

Question 18

Ohms law

Answer 18

V=IR
(voltage) = (current)(resistance)
used to measure pacemaker lead impedance

Question 19

For maximum electrical safety, the ECG monitored patient should be _____, and the monitor chassis should be _____, or nonconductive.

Answer 19

ungrounded, grounded

Question 20

In the ICU, when recording an intracardiac ECG from a pacing electrode or pericardiocentesis needle in the heart, it is safest to:

Answer 20

Use a battery powered monitor or only use an instrument known to have a leakage current of less than 10 uA

Question 21

When you plug in an electric instrument, you are alarmed when sparks fly from the wall outlet. The most likely electrical safety problem is a:

Answer 21

Machine off-on switch was left on

Question 22

The prefix “centi” corresponds to:

Answer 22

1/100

Question 23

prefix from smallest to largest

Answer 23

nano, micro, milli, centi

Question 24

nano

Answer 24

10-9

Question 25

micro

Answer 25

10-6

Question 26

milli

Answer 26

10-3

Question 27

centi

Answer 27

10-2

Question 28

kg to lbs

Answer 28

kg = lbs/2.2
lbs = 2.2*kg

Question 29

Degrees to Celsius formula

Answer 29

C = (5/9)(F-32)
F = (9/5)C+32

Question 30

Formula to calculate heart rate

Answer 30

rate = 60,000/RR interval