IBHRE Study Material: GTP Trivia
Questions and Answers 100% Solved
Most common form of SVT AVNRT
AVNRT Characteristics 1. prolonged PR interval in the beat that starts reentry 2. HR: 150-
250 bpm 3. neck pounding, palpitations, light-headiness, near-syncope 4. narrow QRS 5. abrupt
onset and termination of episodes 6. more common in women 7. frequently presents after age
20
rheobase the lowest point on a strength-duration curve at an infinitely long pulse
duration
chronaxie time pulse width at twice the rheobase value; approximates the most efficient
stimulation pulse duration
resting (transmembrane) potential voltage difference between the inside and outside of
the cell fiber
Single chanmber, ventricular pacing is usually only indicated in the presence of what?
chronic AF
Atrial naturetic peptide (ANP) aka brain naturetic peptide (BNP) a substance produced by
the atrium when the muscle is subjected to higher than normal pressure --> increased levels of
ANP may also be pointing to VVI pacing or loss of atrial capture/synchrony as the culprit
sites used for the ablation of the slow pathway with AVNRT range from midseptal region
between the compact AV mnode and the CS os to the posteriolateral region around the os
,successful AVNRT ablation indicated by: 1. an accelerated junctional rhythm w/ 1:1 VA
conduction during the burn 2. increase in refractoriness of the anterograde AV node 3.
elimination or alteration in dual AV nodal physiology
3 devices with no effect to pacemakers microwave, CT scan/ultrasound, x-rays
5 devices that may affect a pacemaker MRI, defibrillator, cardioversion, cautery/RF
ablation, radiation therapy
devices that cause transient or 1 beat inhibition to pacing electronic article surveillance,
cell phones, arc welding, airport metal detectors, TENS nurve stimulator, electronic appliances
series resistance formula and example Rt= R1 + R2; lead fracture (which leads to increase
in impedance)
parallel resistance formula and example Rt = R1R2/R1+R2; lead insulation defect (which
leads to decrease in impedance)
small load refers to a constant _______ device; large load refers to a constant ___________
device current; voltage
PPM indicated when: 1. symptomatic 2. HR< 40 3. documented asystole > 3 sec (can be
asymptomatic with 2 and 3)
ICD Capacitance Range 90-150 micro farad
DFT thresholds may be lower for _____ output capacitors Smaller
, Low capacitor means high voltage, which means faster waveform
Higher Impedance (results in) Higher threshold and DFT voltage (results in)
Low Impedance (trends towards) Higher tilt (trends towards)
Higher Impedance results in Higher voltage
Steroid-eluting elctrodes: acute threshold phase is relatively ______ compared to non-steroid
electrodes. flat
Steroid-eluting electrodes: initial capture threshold is _____ to non-steroid electrodes.
similar
4 cons to silicone rubber 1. high friction coefficient
2. absorbs lipids
3. more thrombogenic
4. large diameter compared to polyurethane
GOOD polyurethane 55D
BAD polyurethane 80A
3 cons to polyurethane 1. cannot be repaired
2. relatively stiff
3. hard to make
Questions and Answers 100% Solved
Most common form of SVT AVNRT
AVNRT Characteristics 1. prolonged PR interval in the beat that starts reentry 2. HR: 150-
250 bpm 3. neck pounding, palpitations, light-headiness, near-syncope 4. narrow QRS 5. abrupt
onset and termination of episodes 6. more common in women 7. frequently presents after age
20
rheobase the lowest point on a strength-duration curve at an infinitely long pulse
duration
chronaxie time pulse width at twice the rheobase value; approximates the most efficient
stimulation pulse duration
resting (transmembrane) potential voltage difference between the inside and outside of
the cell fiber
Single chanmber, ventricular pacing is usually only indicated in the presence of what?
chronic AF
Atrial naturetic peptide (ANP) aka brain naturetic peptide (BNP) a substance produced by
the atrium when the muscle is subjected to higher than normal pressure --> increased levels of
ANP may also be pointing to VVI pacing or loss of atrial capture/synchrony as the culprit
sites used for the ablation of the slow pathway with AVNRT range from midseptal region
between the compact AV mnode and the CS os to the posteriolateral region around the os
,successful AVNRT ablation indicated by: 1. an accelerated junctional rhythm w/ 1:1 VA
conduction during the burn 2. increase in refractoriness of the anterograde AV node 3.
elimination or alteration in dual AV nodal physiology
3 devices with no effect to pacemakers microwave, CT scan/ultrasound, x-rays
5 devices that may affect a pacemaker MRI, defibrillator, cardioversion, cautery/RF
ablation, radiation therapy
devices that cause transient or 1 beat inhibition to pacing electronic article surveillance,
cell phones, arc welding, airport metal detectors, TENS nurve stimulator, electronic appliances
series resistance formula and example Rt= R1 + R2; lead fracture (which leads to increase
in impedance)
parallel resistance formula and example Rt = R1R2/R1+R2; lead insulation defect (which
leads to decrease in impedance)
small load refers to a constant _______ device; large load refers to a constant ___________
device current; voltage
PPM indicated when: 1. symptomatic 2. HR< 40 3. documented asystole > 3 sec (can be
asymptomatic with 2 and 3)
ICD Capacitance Range 90-150 micro farad
DFT thresholds may be lower for _____ output capacitors Smaller
, Low capacitor means high voltage, which means faster waveform
Higher Impedance (results in) Higher threshold and DFT voltage (results in)
Low Impedance (trends towards) Higher tilt (trends towards)
Higher Impedance results in Higher voltage
Steroid-eluting elctrodes: acute threshold phase is relatively ______ compared to non-steroid
electrodes. flat
Steroid-eluting electrodes: initial capture threshold is _____ to non-steroid electrodes.
similar
4 cons to silicone rubber 1. high friction coefficient
2. absorbs lipids
3. more thrombogenic
4. large diameter compared to polyurethane
GOOD polyurethane 55D
BAD polyurethane 80A
3 cons to polyurethane 1. cannot be repaired
2. relatively stiff
3. hard to make
