IBHRE Prep Exam UPDATED Exam
Questions and CORRECT Answers
Voltage is? - CORRECT ANSWER - The electromotive force pushing on electrons
If the PM output voltage is 5v and the measured lead resistance is 330 ohms, then the current that
flows out of the pacemaker into the heart is? - CORRECT ANSWER - 15.15
I=V/R=5V/.33 k ohm
If a unipolar lead wire has an insulation break one would expect the resistance to? - CORRECT
ANSWER - decrease
for a wire fracture the resistance? - CORRECT ANSWER - increases
if the output vlotage of the pacemaker is programmed from 5 volts to 2.5 volts, the energy
delivered to the heart is? - CORRECT ANSWER - quartered
Which of the following affect the longevity of the PM? - CORRECT ANSWER - output
voltage, resistance of lead and amount % pacing
Which Pt's PM will last longer? - CORRECT ANSWER - #1: AMP=5V, L.R.=90,
resistance 500ohms, PW=.5ms, 100%pacing
#2: AMP=5V, L.R.=60, resistance 500ohms, PW=.5ms, 100%pacing
#3: AMP=2.5V, L.R.=60, resistance 330ohms, PW=.5ms, 100% pacing
(#4: AMP=2.5v, L.R.=60, resistance 500ohms, PW=.5ms, 50%pacing)
The strength duration curve is dependent on the? - CORRECT ANSWER - Cell's
membrane capacitance, intracellular and extracellular resistance and threshold voltage.
, A patient on flecainide should? - CORRECT ANSWER - Have their threshold checked
The acute threshold peaking is due to? - CORRECT ANSWER - Trauma and inflammation
An advantage of bipolar leads is? - CORRECT ANSWER - They are less susceptible to
EMI
The two parameters that are important for ventricular sensing and should be measured are? -
CORRECT ANSWER - R-wave amplitude and slew rate
If an external PM is set to a sensitivity setting of 5mV and some R-waves go unsensed, then you
should do the following - CORRECT ANSWER - Increase sensing by lowering sensitivity
to 2.5mV.
Typical acceptable R-wave amplitude values for an acute ventricular lead is? - CORRECT
ANSWER - 7-15mV
Typical acceptable P wave amplitude values for an acute atrial lead is? - CORRECT
ANSWER - greater than 2mV
The slew rate is? - CORRECT ANSWER - Change in voltage divided by time or the slope
of the EGM
Typical lead resistance range measured in ohms is? - CORRECT ANSWER - 300-2000
ohms
At the time of implant we want a threshold? - CORRECT ANSWER - at .5ms to be less
than 1 volt for ventricle
When connecting a unipolar PM to the lead in the patient? - CORRECT ANSWER - place
the PM in the pocket to check pacing
Questions and CORRECT Answers
Voltage is? - CORRECT ANSWER - The electromotive force pushing on electrons
If the PM output voltage is 5v and the measured lead resistance is 330 ohms, then the current that
flows out of the pacemaker into the heart is? - CORRECT ANSWER - 15.15
I=V/R=5V/.33 k ohm
If a unipolar lead wire has an insulation break one would expect the resistance to? - CORRECT
ANSWER - decrease
for a wire fracture the resistance? - CORRECT ANSWER - increases
if the output vlotage of the pacemaker is programmed from 5 volts to 2.5 volts, the energy
delivered to the heart is? - CORRECT ANSWER - quartered
Which of the following affect the longevity of the PM? - CORRECT ANSWER - output
voltage, resistance of lead and amount % pacing
Which Pt's PM will last longer? - CORRECT ANSWER - #1: AMP=5V, L.R.=90,
resistance 500ohms, PW=.5ms, 100%pacing
#2: AMP=5V, L.R.=60, resistance 500ohms, PW=.5ms, 100%pacing
#3: AMP=2.5V, L.R.=60, resistance 330ohms, PW=.5ms, 100% pacing
(#4: AMP=2.5v, L.R.=60, resistance 500ohms, PW=.5ms, 50%pacing)
The strength duration curve is dependent on the? - CORRECT ANSWER - Cell's
membrane capacitance, intracellular and extracellular resistance and threshold voltage.
, A patient on flecainide should? - CORRECT ANSWER - Have their threshold checked
The acute threshold peaking is due to? - CORRECT ANSWER - Trauma and inflammation
An advantage of bipolar leads is? - CORRECT ANSWER - They are less susceptible to
EMI
The two parameters that are important for ventricular sensing and should be measured are? -
CORRECT ANSWER - R-wave amplitude and slew rate
If an external PM is set to a sensitivity setting of 5mV and some R-waves go unsensed, then you
should do the following - CORRECT ANSWER - Increase sensing by lowering sensitivity
to 2.5mV.
Typical acceptable R-wave amplitude values for an acute ventricular lead is? - CORRECT
ANSWER - 7-15mV
Typical acceptable P wave amplitude values for an acute atrial lead is? - CORRECT
ANSWER - greater than 2mV
The slew rate is? - CORRECT ANSWER - Change in voltage divided by time or the slope
of the EGM
Typical lead resistance range measured in ohms is? - CORRECT ANSWER - 300-2000
ohms
At the time of implant we want a threshold? - CORRECT ANSWER - at .5ms to be less
than 1 volt for ventricle
When connecting a unipolar PM to the lead in the patient? - CORRECT ANSWER - place
the PM in the pocket to check pacing
