CCDS IBHRE EVALUATION EXAM 2026 QUESTIONS AND
SOLUTIONS RATED A+
✔✔polyurethane lead insulation cons - ✔✔1. cannot be repaired
2. relatively stiff
3. hard to make
✔✔Pacemaker Syndrome Causes - ✔✔1. Loss of AV synchrony
2. Sustained retrograde conduction
3. A single ventricular rate when rate modulation is required for exercise
Approx 25% of patients only paced from the ventricle may have some level of severity
related to pacemaker syndrome
✔✔Pacemaker syndrome diagnosis - ✔✔1. Observe fluctuation in the peripheral blood
pressure
2. Cannon "A" wave in the neck
3. History alone
✔✔Pacemaker syndrome management - ✔✔Restore AV synchrony
in ventricular only PM -->lower the pacing rate to minimize ventricular only pacing
DO NOT increase the pacing rate
✔✔Fallback - ✔✔1. Decouples atrial & ventricular events at the upper rate limit
2. The ventricular inhibited pacing rate then gradually decrements to a programmed
lower or "fallback" rate over a programmed duration
3. When the fallback rate is reached, atrial synchrony is restored
✔✔Rate smoothing - ✔✔1. Eliminated large cycle to cycle variations by preventing
paced rate from changing more than a certain percentage (3%, 6%, 12%, etc) from one
V-V interval to the next
2. Eliminates large fluctuations in rate during fixed-ratio or psuedo-Wenckebach block
FOUND IN GDT devices
✔✔sensor upper rate behavior - ✔✔if the sinus rate is faster than the sensor indicated
rate, P synchronous pacing occurs
if the sensor indicated rate is faster, AV pacing at the sensor indicated rate occurs
mixed scenario: when the device is sensor driven AV pacing for a few cycles and a
sinus rate sudden emerges faster than the sensor indicated rate. The sensor driven
atrial output will be inhibited, a PR interval started, and a ventricular output will occur at
the end of the sensor AV interval. That is, the ventricular rate will be equal to the sensor
indicated rate, but the PV interval may be longer than expected
,✔✔Medtronic Rate Drop Response - ✔✔1. Increase in HR (Pacer is programmed to a
top rate)
2. Rise in HR is immediately followed by a fall in HR. (pacer is programmed to a
"bottom" rate
3.The HR drop must be identified, therefore a number of "Width" beats must be
programmed the HR must fall to the bottom rate in fewer than the programmed "width"
beats
4. To confirm the rate drop, a small number of confirmation beats must be programmed.
The HR must remain below the bottom rate for this number of confirmation beats in
order for the algorithm to activate
✔✔Tilt Testing Results for RDR - ✔✔1. An initial rise in the HR to a value at or above
the "Top Rate" must occur
2. A rapid fall in HR must then follow
3. A fall in BP resulting in symptoms must occur next
4. Syncope should not occur until the HR has dropped by 20-30 bpm
✔✔X-ray Exposure (formula) - ✔✔Exposure= exposure rate x time
✔✔Longevity calculation - ✔✔longevity is usable battery in Amp Hours
Pacer current drain = in micro amps
hours in one year = 8760 hours
Usable battery capacity/pacer current drain = # of hours
Battery longevity (in yrs)= 114x(Ahr battery capacity)/(current drain in uA)=c
✔✔Bisping Coaxial Lead - ✔✔Bisping is an extendable/retractable helix type lead. MDT
owns the patent
✔✔Chagas disease - ✔✔Vector: kissing bug in central & south America
Symptoms: acute heart infection & symptoms subside within 4 to 8 weeks
If goes unrecognized, the disease can surface 10-20 yrs later in the form of chronic
heart disease. Infected heart muscle fibers are replaced by scar tissue, thinning the
walls of the heart.
The nervous system may also be affected
✔✔Persistent SVC - ✔✔SVC connects to RA via CS (90%)
✔✔Lyme's Disease - ✔✔Varying degrees of AV block
, ✔✔Upper Limit of Vulnerability - ✔✔the weakest shock strength at or above which VF is
not induced when the shock is delivered at any time during the vulnerable period.
✔✔AVNRT - ✔✔- AV node can be thought of as divided into two conduction pathways
- premature impulse is blocked in the fast pathway
- impulse travels down the slow pathway
- impulse again reaches the fast pathway in retrograde fashion
- impulse then reenter the slow pathyway
✔✔rule of thumb for AVNRT ablation, which pathway should you ablate? (slow vs fast) -
✔✔slow pathway because ablation of fast pathway will significantly increase the risk of
complete heart block
✔✔a successful ablation of slow pathway in AVNRT is indicated by: - ✔✔1. an
accelerated junctional rhythm with 1:1 VA conduction during the burn
2. an increase in refractoriness of the anterograde AV node
3. elimination or alteration in dual AV nodal physiology
✔✔Complication of fast pathway ablation in AVNRT - ✔✔1. high grade heart block
2. marked first degree heart block
3. pseudo-pacemaker syndrome caused by prolonged AV conduction times resulting in
atrial contraction during AV valve closure
4. persistence of atypical AV nodal reentry implying slow pathways as both the
antegrade and retrograde limbs of the tachycardia
✔✔p wave characteristics in AVNRT - ✔✔- negative in inferior leads
- positive in V1
✔✔Resting (transmembrane) potential - ✔✔the voltage difference between the inside
and the outside of the cell fiber
✔✔Action potential - ✔✔5 phases, the cellular characteristics of depolarization and
repolarization
✔✔Action potential phase 0 - ✔✔The depolarization phase
The rapid sodium channels are stimulated to open causing the resting transmembrane
from above -90mV to about 0mV
✔✔Action potential phase 1 - ✔✔early repolarization
✔✔Action potential phase 2 - ✔✔The plateau phase
mediated by the slow calcium channels essentially disrupts and delays the
repolarization started in phase 1 and prolonged the refractory period
SOLUTIONS RATED A+
✔✔polyurethane lead insulation cons - ✔✔1. cannot be repaired
2. relatively stiff
3. hard to make
✔✔Pacemaker Syndrome Causes - ✔✔1. Loss of AV synchrony
2. Sustained retrograde conduction
3. A single ventricular rate when rate modulation is required for exercise
Approx 25% of patients only paced from the ventricle may have some level of severity
related to pacemaker syndrome
✔✔Pacemaker syndrome diagnosis - ✔✔1. Observe fluctuation in the peripheral blood
pressure
2. Cannon "A" wave in the neck
3. History alone
✔✔Pacemaker syndrome management - ✔✔Restore AV synchrony
in ventricular only PM -->lower the pacing rate to minimize ventricular only pacing
DO NOT increase the pacing rate
✔✔Fallback - ✔✔1. Decouples atrial & ventricular events at the upper rate limit
2. The ventricular inhibited pacing rate then gradually decrements to a programmed
lower or "fallback" rate over a programmed duration
3. When the fallback rate is reached, atrial synchrony is restored
✔✔Rate smoothing - ✔✔1. Eliminated large cycle to cycle variations by preventing
paced rate from changing more than a certain percentage (3%, 6%, 12%, etc) from one
V-V interval to the next
2. Eliminates large fluctuations in rate during fixed-ratio or psuedo-Wenckebach block
FOUND IN GDT devices
✔✔sensor upper rate behavior - ✔✔if the sinus rate is faster than the sensor indicated
rate, P synchronous pacing occurs
if the sensor indicated rate is faster, AV pacing at the sensor indicated rate occurs
mixed scenario: when the device is sensor driven AV pacing for a few cycles and a
sinus rate sudden emerges faster than the sensor indicated rate. The sensor driven
atrial output will be inhibited, a PR interval started, and a ventricular output will occur at
the end of the sensor AV interval. That is, the ventricular rate will be equal to the sensor
indicated rate, but the PV interval may be longer than expected
,✔✔Medtronic Rate Drop Response - ✔✔1. Increase in HR (Pacer is programmed to a
top rate)
2. Rise in HR is immediately followed by a fall in HR. (pacer is programmed to a
"bottom" rate
3.The HR drop must be identified, therefore a number of "Width" beats must be
programmed the HR must fall to the bottom rate in fewer than the programmed "width"
beats
4. To confirm the rate drop, a small number of confirmation beats must be programmed.
The HR must remain below the bottom rate for this number of confirmation beats in
order for the algorithm to activate
✔✔Tilt Testing Results for RDR - ✔✔1. An initial rise in the HR to a value at or above
the "Top Rate" must occur
2. A rapid fall in HR must then follow
3. A fall in BP resulting in symptoms must occur next
4. Syncope should not occur until the HR has dropped by 20-30 bpm
✔✔X-ray Exposure (formula) - ✔✔Exposure= exposure rate x time
✔✔Longevity calculation - ✔✔longevity is usable battery in Amp Hours
Pacer current drain = in micro amps
hours in one year = 8760 hours
Usable battery capacity/pacer current drain = # of hours
Battery longevity (in yrs)= 114x(Ahr battery capacity)/(current drain in uA)=c
✔✔Bisping Coaxial Lead - ✔✔Bisping is an extendable/retractable helix type lead. MDT
owns the patent
✔✔Chagas disease - ✔✔Vector: kissing bug in central & south America
Symptoms: acute heart infection & symptoms subside within 4 to 8 weeks
If goes unrecognized, the disease can surface 10-20 yrs later in the form of chronic
heart disease. Infected heart muscle fibers are replaced by scar tissue, thinning the
walls of the heart.
The nervous system may also be affected
✔✔Persistent SVC - ✔✔SVC connects to RA via CS (90%)
✔✔Lyme's Disease - ✔✔Varying degrees of AV block
, ✔✔Upper Limit of Vulnerability - ✔✔the weakest shock strength at or above which VF is
not induced when the shock is delivered at any time during the vulnerable period.
✔✔AVNRT - ✔✔- AV node can be thought of as divided into two conduction pathways
- premature impulse is blocked in the fast pathway
- impulse travels down the slow pathway
- impulse again reaches the fast pathway in retrograde fashion
- impulse then reenter the slow pathyway
✔✔rule of thumb for AVNRT ablation, which pathway should you ablate? (slow vs fast) -
✔✔slow pathway because ablation of fast pathway will significantly increase the risk of
complete heart block
✔✔a successful ablation of slow pathway in AVNRT is indicated by: - ✔✔1. an
accelerated junctional rhythm with 1:1 VA conduction during the burn
2. an increase in refractoriness of the anterograde AV node
3. elimination or alteration in dual AV nodal physiology
✔✔Complication of fast pathway ablation in AVNRT - ✔✔1. high grade heart block
2. marked first degree heart block
3. pseudo-pacemaker syndrome caused by prolonged AV conduction times resulting in
atrial contraction during AV valve closure
4. persistence of atypical AV nodal reentry implying slow pathways as both the
antegrade and retrograde limbs of the tachycardia
✔✔p wave characteristics in AVNRT - ✔✔- negative in inferior leads
- positive in V1
✔✔Resting (transmembrane) potential - ✔✔the voltage difference between the inside
and the outside of the cell fiber
✔✔Action potential - ✔✔5 phases, the cellular characteristics of depolarization and
repolarization
✔✔Action potential phase 0 - ✔✔The depolarization phase
The rapid sodium channels are stimulated to open causing the resting transmembrane
from above -90mV to about 0mV
✔✔Action potential phase 1 - ✔✔early repolarization
✔✔Action potential phase 2 - ✔✔The plateau phase
mediated by the slow calcium channels essentially disrupts and delays the
repolarization started in phase 1 and prolonged the refractory period
