IBHRE Prep Exam With 100% Correct
Answers 2025/2026
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.
