Old Exams : EXAM 1 & 2 Flashcards
The letters ECG stand for what?
Electrocardiogram
Name of Waller’s dog used in early experiments?
Jimmie
Type of amplifier used in ECG monitoring?
Differential Input DC Amplifier
How is the right leg lead used in patient ECG monitoring?
Reference / grounding
What is the accuracy calculation?
(# of correct / # total) x 100
Which monitors are used for both the patient and the anesthesia delivery system?
Paw (peak airway)
Qaw (airway flow)
Vt (tidal volume)
Respiratory Gas Analyzer
What is the “J point” definition?
60-80 msec after the QRS
What is the formula for calculating mean arterial pressure?
(Pulse pressure / 3) + diastolic pressure
What is precision?
Degree of consistency between repeated measurements
What is the Nyquist rate used for?
What is Nyquist rate formula?
Used to faithfully reproduce an analog signal into digital form
2 x Fmax
ASA recommendation for the use of a circuit disconnect monitor?
Continuous monitoring
What is “help me” audible alarm?
Advisory audible alarm
1-2 beeps
What does the caution (3 beeps) audible alarm sound like?
“Help me please”
Which audible alarm says “Oh my god, help me” and repeats?
Warning audible alarm
5 beeps
What is the fourier components of a rapidly changing waveform?
Contains many high frequency components
Which is the most sensitive single lead for the detection of myocardial LV ischemia?
V5 = 75% effective
What is the most sensitive lead combination of the detection of myocardial LV ischemia?
V4 , V5, II = 96% effective
(V5 , II = 80%)
(V5, V4 = 90%)
How does the amplitude of R waves change with respiration?
Increases with inspiration
The meaning of the resultant vector in Einthoven’s triangle:
Is the vector component of the depolarizing dipole
What is the most common cause of peri-op arrhythmias?
Bovi ??
can someone please make sure this right i think they meaning the most common cause of seeing arrythmias on waveform, not actual arrythmias from patient however?
What is the location of the V4 ECG lead?
5th intercostal space at the mid-clavicular line
What is the most common type of electrodes used for ECG monitoring?
Ag - AgCl or column electrodes
What is the average amplitude of the R wave?
1 mV
What is the source of common mode interferences?
60 Hz Can occur with : ECG near power cord/source High electrode impedance from poor skin contact Faulty lead wire
What is the location of the V2 ECG lead?
Left Sternal border at 4th intercostal spadce
An normal QRS complex is displayed as a RS complex (no Q wave) in viewing what lead?
Lead III
What is the primary method that skin electrodes make contact with the volume conductor of the body?
Capacitive coupling through pores
What waves present during ventricular depolarization?
QRS
The AHA (american heart association) recommends what Hz for ECG diagnostic amplifiers?
0.05 Hz - 100 Hz
Which plane is seen between cardiac vector degrees 110* to - 30*?
Frontal plane
The transverse plane can be seen between what range of cardiac vectors?
30* to - 30*
The functions of an ECG monitor that requires the highest frequency range?
Pacemakers
What is “propagation of depolarization is seen as moving separation of charges”?
Dipole theory
What are examples of ECG manifestations of ischemia?
Peak T waves ST elevation ST depression T wave inversion Q wave
What is the requirement of ASA standards of ECG monitoring?
Continuous
Augmented vector leads provide how much augmentation?
50%
What is the normal duration of S-T interval?
0.26 sec
Einthoven’s LAW
II = I + III
What is the most common mechanism that creates signal artifact in ECG?
Electrode slippage
MI (infarction) would be interpreted how?
Upward sloping S-T segments
Definition of specificity?
How reliable the device is at detecting true abnormal readings
What is the definition of an ECG interval?
From the beginning of one wave to beginning of another
Meaning of “continual”?
Repeated , non-stop
What is the definition of drift on signal reproduction?
Slow, low frequency component of the signal
What ion crosses the cell membrane during the initial depolarization of myocardial contraction?
Na
aVR lead use what leads?
RA lead (+) LA , LL leads (-)
Which term means the degree of consistency between repeated measurements of the same quantity?
Precision
During LV depolarization, aVR lead will have what kind of deflection?
Negative deflection
Biphasic waves have what kind of axis?
Perpendicular 90* axis
What is full scale accuracy variation?
+/- 1 standard deviation
Bradycardia is what kind of sinus arrhythmia?
Benign sinus arrhythmia
What is reproducibility ?
Ability to maintain precision during long term use
What fixes random errors in monitoring?
Averaging fixes random errors
Meaning of “stethescope”?
Chest exam
What electrode is white?
RA
What electrode color is LL?
Red
What electrode is black?
LA
What color is the reference electrode and how is labeled?
Green
RL
Precordial (V) lead is what color?
Brown
What is the ASA motto?
Vigilance
What in the cell maintains electrical potential differences?
Na - K pump
What is the A-H interval?
The time from initial deflection of the atrial wave to the deflection of the bundle of HIS
What does the A-H interval approximate and how long is it?
Approximates the conduction time through the AV node.
normally 50 -120 msec
What is the interference theory?
Theory in which some tissue repolarizes (myocardium) in the opposite direction of the depolarization. The ECG then is a result of the spatial and temporal summation of electrical activity of the heart as seen by electrodes placed externally
Vector I has what 2 possible axis degrees?
0 and +/- 180 degrees
Vector II has what 2 possible axis degrees?
+60 and -120 degrees
Vector III has what 2 possible axis degrees?
+120 and -60 degrees
What kind of wave does hyperkalemia cause?
U wave
How long are each of the segments and waves in the ECG?
P-R segment = 0.08 msec P-R Interval = 0.16 msec QRS complex = 0.06 -0.10 msec S-T segment = 0.12 msec S-T interval = 0.28 msec Q-T Interval = 0.36 msec
What is the best way for determining heart rate?
What is the second most used way?
Arterial waveform Pulse ox (but remember tells you pulse rate)
Kirchhoff’s Voltage law is what?
The sum of the voltage variations around a loop is zero. Rt = R1 + R2 + R2
Kirchhoff’s Current law is what?
The sum of all currents that converge on a node will be zero. (1/Rt) = (1/R1) + (1/R2) + (1/R3)
What is also known as the balance equation?
The wheatstone bridge
Capacitors =
compliance
Series capacitance equation
(1/Ct) = (1/C1) + (1/C2) + (1/C3)
Opposite charges get so close that they cancel each other out
Parallel capacitance equation
Ct = C1 + C2 + C3
In series capacitance, what happens to current?
Current decreases as time increases due to charge buildup on capacitor.
Current also increases as time increases due to diminished impediment from the inductor
In series capacitance, what happens to voltage?
Voltage across the capacitor increases as time increase due to charge buildup on capacitor
Inductors =
inertness
Series inductance equation?
Lt = L1 + L2 + L3
Parallel inductance equation?
(1/Lt) = (1/L1) + (1/L2) + (1/L3)
Most circulatory systems are what kind of system?
Parallel systems
The electrical diode is analogous to what in vascular system?
Vascular valve
The maximum amplitude in either the positive or negative half cycle?
Peak amplitude
Peak to peak amplitude is what?
twice the peak amplitude and includes positive to negative maxima
Average amplitude is what?
the average amplitude for either half cycle
= 0.637 x peak amplitude
The amplitude a DC signal would need to be in order to provide the same average power is what?
RMS amplitude (root mean square) = 0.707 x peak amplitude
What is the most dangerous frequency?
50 - 60 Hz
What is the branch of chemistry concerned with measuring the proportions of elements that combine when chemical reactions take place?
Stoichiometry
What is the rule of arrhenius?
The rate of a reaction is doubled when the temperature of the initial mixture is raised by 10*C
What does PASS for fire extinguishers mean?
Pull the pin
Aim the nozzle
Squeeze the trigger
Sweep from side to side
What is unit that measures the amount of radiation being given off or emitted by radioactive material?
Ci (curie)
The Rad or grey measures what?
The radiation dose absorbed by a person (the amount of energy deposited in human tissue by radiation)
Name 2 high energy lasers
Geiger
Scintillation
T or F: The x-ray is high frequency protons?
TRUE
The most dangerous laser for skin?
Excimer
The most dangerous laser for subcutaneous layer?
CO2
The most dangerous deep tissue laser?
YAG
What risk of lasers is associated with a “sizzle”?
Direct intrabeam viewing
What risk of lasers is associated with a “pop”?
Specular reflection
What risk of lasers is associated with “ouch”?
Diffuse reflection
The laser hazard associated with atmospheric contamination?
Laser plume
Laser injuries breakdown
Perforation : 24%
Gas embolism : 24%
Eye exposure: 19%
Other burns: 9%
% difference
A-B / average
% error
(True- measured)/true
Sensitivity
Hit / (hits + misses)
Specificity
Correct rejections/ (correct+false alarms )
What is most immediate indication of circuit disconnect?
Bellows collapse
Recognition of the CS5 lead
RA lead placed centrally near subclavian artery
LA misplaced at V5 or leads switched
Waveform selected to view would be Lead I
What is the most common cause of upward sloping ST segments?
Infarction
Augmented vector leads provide what percent augmentation?
50%
What is the only continuous ASA monitoring standard?
ECG
Circulation, Oxygen, Vent are all continual
What is most immediate indication of circuit disconnect?
Bellows collapse
Recognition of the CS5 lead
RA lead placed centrally near subclavian artery
LA misplaced at V5 or leads switched
Waveform selected to view would be Lead I
What is the most common cause of upward sloping ST segments?
Infarction
Augmented vector leads provide what percent augmentation?
50%
What is the only continuous ASA monitoring standard?
ECG
Circulation, Oxygen, Vent are all continual
What is most immediate indication of circuit disconnect?
Bellows collapse
Recognition of the CS5 lead
RA lead placed centrally near subclavian artery
LA misplaced at V5 or leads switched
Waveform selected to view would be Lead I
What is the most common cause of upward sloping ST segments?
Infarction
Augmented vector leads provide what percent augmentation?
50%
What is the only continuous ASA monitoring standard?
ECG
Circulation, Oxygen, Vent are all continual