IBHRE
Lithium iodine battery V? - ANS-2.8V- not used for ICDs due to low peak power. Qmr
Lithium Iodine/ silver V? - ANS-3.2V Qhr- used for ICDS
Which is an example of a closed loop sensor? - ANS-myocardial contractility and O2
stat
Primary Sensor - ANS-detects changes in normal physiologic responses
Secondary - ANS-detects internal changes from exercise- QT MV pH
Tertiary - ANS-detects changes as a result of exercise- piezo accelerometer
The smaller the cathode surface the- - ANS-higher the current density, lower the
threshold, and higher the impedance (2-6mm as small as 1.2)
Anode should be how much bigger than the cathode? - ANS-3xs (4-20mm in pacing
leads)
ICD tip electrodes tend to run- - ANS-2-10mm
Rv coil size? - ANS-300-600mm
SVC coil size? - ANS-400-860mm
OHMS LAW - ANS-V=I * R
ENERGY EQUATION (uJ) - ANS-V * I* PW
I is what? - ANS-Current- flow of electrons through a circuit
What can cause increase in threshold, wide QRS, latency, and undersensing? -
ANS-Hyperkalemia- high levels of potassium
Hypercalcemia can result in? - ANS-Short QT
, Hypocalcemia can result in? - ANS-Long QT
Normal Potassium level? - ANS-3.7-5.2
estimated battery life? Time= - ANS-Time= Q (battery capacity in Ah) / I ( current drain
in amperes)
Which of the following is necessary to initiate reentry tachy? - ANS-unidirectional block
of one pathway (travels down the slow up the fast) can be large (WPW) or small
(AVNRT)
Slew Rate - ANS-max rate of change between the sensing electrode and first derivative
on ECG
change in V/ Change in TIme
Frequency - ANS-# of times a signal fluctuates in 1 sec expressed in hertz
The Basic Unit of Capacitance is? - ANS-Farad
Basic Unit of Energy? - ANS-Joule
Unit of charge? - ANS-Coulomb= 1 amp per second
Microvolt T wave testing - ANS-measures beat to beat variations in the T wave,
performed with exercise ideally hr between 105 and 110
Heart Rate turbulence - ANS-looks at 10 to 20 beats following a PVC. absence of it is
the best non invasive prediction of cardiac mortality following a MI
Fluoroquinolone antibiotic is known for what cardiac effect? - ANS-prolonging the QT
Zener Diode - ANS-protects the pacemaker circuitry from high external voltages
rheobase - ANS-lowest possible voltage that will stimulate the myocardium at any pulse
duration
chronaxie - ANS-twice the rheobase voltage
watt-second - ANS-energy
Lithium iodine battery V? - ANS-2.8V- not used for ICDs due to low peak power. Qmr
Lithium Iodine/ silver V? - ANS-3.2V Qhr- used for ICDS
Which is an example of a closed loop sensor? - ANS-myocardial contractility and O2
stat
Primary Sensor - ANS-detects changes in normal physiologic responses
Secondary - ANS-detects internal changes from exercise- QT MV pH
Tertiary - ANS-detects changes as a result of exercise- piezo accelerometer
The smaller the cathode surface the- - ANS-higher the current density, lower the
threshold, and higher the impedance (2-6mm as small as 1.2)
Anode should be how much bigger than the cathode? - ANS-3xs (4-20mm in pacing
leads)
ICD tip electrodes tend to run- - ANS-2-10mm
Rv coil size? - ANS-300-600mm
SVC coil size? - ANS-400-860mm
OHMS LAW - ANS-V=I * R
ENERGY EQUATION (uJ) - ANS-V * I* PW
I is what? - ANS-Current- flow of electrons through a circuit
What can cause increase in threshold, wide QRS, latency, and undersensing? -
ANS-Hyperkalemia- high levels of potassium
Hypercalcemia can result in? - ANS-Short QT
, Hypocalcemia can result in? - ANS-Long QT
Normal Potassium level? - ANS-3.7-5.2
estimated battery life? Time= - ANS-Time= Q (battery capacity in Ah) / I ( current drain
in amperes)
Which of the following is necessary to initiate reentry tachy? - ANS-unidirectional block
of one pathway (travels down the slow up the fast) can be large (WPW) or small
(AVNRT)
Slew Rate - ANS-max rate of change between the sensing electrode and first derivative
on ECG
change in V/ Change in TIme
Frequency - ANS-# of times a signal fluctuates in 1 sec expressed in hertz
The Basic Unit of Capacitance is? - ANS-Farad
Basic Unit of Energy? - ANS-Joule
Unit of charge? - ANS-Coulomb= 1 amp per second
Microvolt T wave testing - ANS-measures beat to beat variations in the T wave,
performed with exercise ideally hr between 105 and 110
Heart Rate turbulence - ANS-looks at 10 to 20 beats following a PVC. absence of it is
the best non invasive prediction of cardiac mortality following a MI
Fluoroquinolone antibiotic is known for what cardiac effect? - ANS-prolonging the QT
Zener Diode - ANS-protects the pacemaker circuitry from high external voltages
rheobase - ANS-lowest possible voltage that will stimulate the myocardium at any pulse
duration
chronaxie - ANS-twice the rheobase voltage
watt-second - ANS-energy
