EP Basics Flashcards
Which of the following is the MOST important consideration when selecting a site for a peripheral IV in a pt undergoing a device implant?
Patient preference, length of hospital stay, planned site of implant, or type of IV fluid
PLANNED SIDE OF IMPLANT
What is informed consent?
Prior to starting the case and after explaining the procedure to the patient as well as identifying risks and potential complications permission is given to proceed with the study
What is implied consent?
the granting of permission for health care without a formal agreement between the patient and health care provider. An example is an appointment made with a physician by a pt with a physical complaint; it is implied that by making the appointment the pt gives consent to the physician to make a diagnosis and offer treatment.
What is patient authorization?
apps. leg.wa.gov/RCW/default.aspx?cite=70.02.030
(1) A patient may authorize a health care provider or health care facility to disclose the patient’s health care information. A health care provider or health care …
What is authorization to treat?
Authorization to Treat Form I, _____ (Parent/Guardian Name) hereby give permission for any and all medical attention to be administered to my …
During phase 2 of the action potential there is a slow influx of which of the following? potassium ions, magnesium ions, sodium ions or calcium ions
Calcium ions
The flow of electric current is measured in: Volts Ohms Watts Amperes
Amps = 1 Coulomb/sec
Electric Current = Amps
What is the term used to denote the total opposition to flow of alternating current in a circuit? Reactance Impedance Inductance Capacitance
Independence or resistance
What is the most common DC electric power source?
Battery. Batteries are an electrochemical source of direct-current. DC current only travels in one direction. Defibrillators used batteries to charge a capacitor.
Electric battery current has a frequency of: 0 hz 60 hz 120 hz 1000 Hz
0 hurts. DC current flows steadily from - to +. It does not alternate back and forth like AC current does.
The illumination of vibrations at certain frequencies is accomplished through the use of electronic devices known as: Diodes Grids Filters Rectifiers
Filters. Most amplifiers have high and low limits beyond which they do not amplify.
ECG amplifiers typically incorporate what kind of filter that cuts off low frequencies less than 0.1 Hz and high frequencies greater than 100 Hz?
Band Pass Filters. Pressure Amps use only a low pass filter because they pass all low frequencies - down to 0 Hz or DC. The upper limit may be changed to increase fidelity and/or reduce motion artifacts.
When a DC defibrillator "charges" it stores electrical energy in its: Batteries capacitors Transformers photovoltaic cells
Capacitors. Large capacitors store the charge. When you charge a defibrillator, large capacitors become polarized and charged up to several thousand volts. This allows for a large amount of electricity to be temporarily stored. When the FIRE button is depressed, the charged capacitor is suddenly discharged into the patient.
How should EP lab external defibrillators be tested?
Discharging paddles into a dummy load. Test firing a defibrillator can be dangerous. It must be fired into a resistance similar to that of human thorax. Many defibrillators have dummy loads built into the paddle rests for this purpose. Discharging paddles against each other or in the air could damage the defibrillator. A patient accidentally shocked on his T-wave could go into VF.
A Watt Second ( or Joule) is a Unit of?
Energy. Defibrillators are charged from 50 to 360 J. Watt second units are similar to the units on your home electricity/energy bill in kilowatt hours. A watt is the product of voltage and current. 1 watt =1 Volt x 1 amp.
What is another name for a watt second?
A Joule
Common units are: Frequency. Force. Energy or work. Power.
Frequency = Hertz = Cycles/sec
Force = Newton = wt in grams
Energy or work = Joule = Ergs
Power = Watt = rate of doing work
What is the current drawn by a resistor of 100 Ohms, if a 10 volt Battery is applied across it?
0.1 amp
V
----- = Ohms Law
I R This is used to measure pacemaker lead impedance. Ohms Law relates current, voltage and resistance just the way cardiac output relates to driving pressure and resistance.
What is Ohms Law?
V
—-
I R
Using Ohm’s Law, calculate the amount of current drawn by a pacemaker if it’s lead resistance is 200 ohms and the pacing voltage is 1 Volt in mA.
5 mA
In electrical injury, the pathway of current most likely to be fatal is:
Hand to hand
Hand to foot
Foot to foot
Foot to ground
Hand-to-hand. Most of the current passes through the chest and heart using much the same path as defibrillation. It is the path most likely to cause ventricular fibrillation. Hand to foot current path is more associated with cardiac muscle damage. To prevent shock, electricians avoid the practice of working with both hands on live circuits.
Lightning strikes on a individual RDC current which is less hazardous than 60 cycle AC current. Also, protective in lightning strikes is a “flashover” phenomenon, where the current travels along the outer surface of the body.
For maximum electrical safety, the ECG monitored patient should be_________and the monitor chassis should be___________, or nonconductive.
Grounded, grounded.
Grounded, ungrounded. Ungrounded, ungrounded. Ungrounded, grounded.
Ungrounded, grounded.
Patients should never be connected directly to ground. This is analogous to standing in a pool of conductive water. A grounded patient becomes a “lightning rod” available to conduct any potential leakage currents. Whereas, if the patient is ungrounded or floating, he does not provide himself a ready conductor to ground.
Most medical instruments at a patient’s bedside are encased in a metal box called the chassis. For safety you should always be grounded through the third prong of the plug. Properly grounded medical equipment safely conducts stray leakage Currents away from the patient to ground. Plastic cases especially battery operated, need not be grounded because they are insulated and cannot conduct leakage currents.
