Page 1 of 76
CCDS IBHRE EXAM NEWEST 2025 PACKAGE DEAL| 2
DIFFERENT VERSIONS WITH COMPLETE 900 REAL
EXAM AND PRACTICE QUESTIONS WITH CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) ALREADY
GRADED A | IBHRE CCDS EXAM PREP 2025 (BRAND
NEW!!)
Rheobase .....ANSWER..... the lowest point on a strength duration
curve at an infinitely long pulse duration
Chronaxie time .....ANSWER..... the pulse width at twice the
rheobase value. It approximates the most efficient stimulation
pulse duration
Charge (formula) .....ANSWER..... Charge= I(current) x T(time)
Furman's formula .....ANSWER..... Energy(microjoules)=
I(current)xV(voltage)xT(pulse width)
,Page 2 of 76
Ohms law formula .....ANSWER..... Voltage(electromotive force)=
I(current/flow of electrons) x R(resistance to current flow in ohms)
Functional Refractory Period .....ANSWER..... the coupling interval
which first results in a measurable degree of delay in impulse
conduction
Effective Refractory Period .....ANSWER..... the longest coupling
interval to be associated with block
Devices with NO interaction with pacers .....ANSWER..... 1.
microwave oven, 2. CT scan/Ultrasound 3. X-rays (diagnostic)
Devices that cause transient or 1 beat inhibition .....ANSWER.....
1. EAS 2. Cellphones 3. Arc Welding 4. airport metal detector 5.
TENS 6. Electric appliances such as electric blanket & power tools
Devices that may damage the pacemaker .....ANSWER..... 1. MRI
2. Defibrillator 3. Cardioversion 4. Cautery/RF Ablation 5.
Radiation Therapy
,Page 3 of 76
Resistance in Series .....ANSWER..... Series means the beginning
of one resistance is connected to another
Sum the resistances: R1+R2= total resistance. EX: A LEAD
FRACTURE (fractures INCREASE impedance)
Resistance in Parallel .....ANSWER..... Parallel means all the
resistances are connected to the same point.
(R1xR2)/(R1+R2)= total resistance
EX: LEAD INSULATION DEFECTS (insulation defects DECREASE
impedance)
Permanent pacemakers are constant voltage or constant current?
.....ANSWER..... ALL permanent pacemakers are constant voltage
devices.
, Page 4 of 76
SOME temp pacemakers are constant voltage, most are constant
current.
LOAD .....ANSWER..... Load refers to impedance (or resistance)
applied to a circuit.
A system with a SMALL load (low impedance) applied to the
circuit is said to be a constant current device
A system with LARGE load is said to be a constant voltage
device
Guidelines for Permanent Pacing .....ANSWER..... 1. Patient is
symptomatic
2. The heart rate is less than 40 bpm
3. Asystole of greater than 3 seconds is documented
CCDS IBHRE EXAM NEWEST 2025 PACKAGE DEAL| 2
DIFFERENT VERSIONS WITH COMPLETE 900 REAL
EXAM AND PRACTICE QUESTIONS WITH CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) ALREADY
GRADED A | IBHRE CCDS EXAM PREP 2025 (BRAND
NEW!!)
Rheobase .....ANSWER..... the lowest point on a strength duration
curve at an infinitely long pulse duration
Chronaxie time .....ANSWER..... the pulse width at twice the
rheobase value. It approximates the most efficient stimulation
pulse duration
Charge (formula) .....ANSWER..... Charge= I(current) x T(time)
Furman's formula .....ANSWER..... Energy(microjoules)=
I(current)xV(voltage)xT(pulse width)
,Page 2 of 76
Ohms law formula .....ANSWER..... Voltage(electromotive force)=
I(current/flow of electrons) x R(resistance to current flow in ohms)
Functional Refractory Period .....ANSWER..... the coupling interval
which first results in a measurable degree of delay in impulse
conduction
Effective Refractory Period .....ANSWER..... the longest coupling
interval to be associated with block
Devices with NO interaction with pacers .....ANSWER..... 1.
microwave oven, 2. CT scan/Ultrasound 3. X-rays (diagnostic)
Devices that cause transient or 1 beat inhibition .....ANSWER.....
1. EAS 2. Cellphones 3. Arc Welding 4. airport metal detector 5.
TENS 6. Electric appliances such as electric blanket & power tools
Devices that may damage the pacemaker .....ANSWER..... 1. MRI
2. Defibrillator 3. Cardioversion 4. Cautery/RF Ablation 5.
Radiation Therapy
,Page 3 of 76
Resistance in Series .....ANSWER..... Series means the beginning
of one resistance is connected to another
Sum the resistances: R1+R2= total resistance. EX: A LEAD
FRACTURE (fractures INCREASE impedance)
Resistance in Parallel .....ANSWER..... Parallel means all the
resistances are connected to the same point.
(R1xR2)/(R1+R2)= total resistance
EX: LEAD INSULATION DEFECTS (insulation defects DECREASE
impedance)
Permanent pacemakers are constant voltage or constant current?
.....ANSWER..... ALL permanent pacemakers are constant voltage
devices.
, Page 4 of 76
SOME temp pacemakers are constant voltage, most are constant
current.
LOAD .....ANSWER..... Load refers to impedance (or resistance)
applied to a circuit.
A system with a SMALL load (low impedance) applied to the
circuit is said to be a constant current device
A system with LARGE load is said to be a constant voltage
device
Guidelines for Permanent Pacing .....ANSWER..... 1. Patient is
symptomatic
2. The heart rate is less than 40 bpm
3. Asystole of greater than 3 seconds is documented
