IBHRE UPDATED EXAMS TEST PAPER QUESTIONS
AND ANSWERS SURE A+
✔✔Indications for a pacemeker - ✔✔-symptomatic patient
-heart rate less than 40 bpm
-asystole greater than 3 sec
✔✔Slew Rate - ✔✔peak slope of an electrogram signal (voltage/time) (dV/dt)
✔✔when is slew rate significant? - ✔✔when there are low amplitude intrinsic signals
✔✔range slew rate should be in atrium - ✔✔>0.3 v/s
✔✔range slew rate should be in ventricle - ✔✔>0.5 v/s
✔✔Pacing thresholds may ________ when sleeping and ________ when awake - ✔✔-
increase
-decrease
✔✔steroid eluting electrodes - ✔✔-corticosteroid dexamethasone sodium phosphate
impregnated in a silicone core
-acute threshold phase is relatively flat
-initial capture threshold is similar to non steroid eluting
, ✔✔pros to silicone pacemaker lead insulation - ✔✔-easily repaired
-flexible
-proven performance
-easy to make
✔✔cons to silicone pacemaker lead insulation - ✔✔-high friction coefficient
-absorbs lipids
-more thrombogenic and fibrotic
-cuts easily
-tears with suture if too tight
-larger diameter
✔✔pros to polyurethane pacemaker lead insulation - ✔✔-relatively
thronbogenetic/fibrotic
-thin walls
-high tear strength
-resists cutting
-low friction coefficient
-abrasion resistant
✔✔cons to polyurethane pacemaker lead insulation - ✔✔-not reparable
-relatively stiff
-hard to make
✔✔Why is polyurethane 80A bad for pacemaker leads? - ✔✔it would biodegrade and
cause insulation issues
✔✔What type pf polyurethane is good for pacemaker leads? - ✔✔55D
✔✔Pacemaker syndrome - ✔✔combination of symptoms occuring with v-pacing that are
relieved by restoring AV synchrony (experienced by 25% of vpaced patients to a degree
✔✔fallback - ✔✔-purpose is to avoid rapid and prolonged vpacing during atrial
arrhythmias
-decouples A and V at upper rate limit
✔✔rate smoothing - ✔✔eliminates large beat to beat variations by not letting pacing
rate change more than a certain percentage from the next interval
✔✔Percent change for rate smoothing in guidant devices - ✔✔3,6,12.5,25
✔✔Rate smoothing - ✔✔looks at last r-r interval and doesn't let the next change by
more than the programmed percentage
AND ANSWERS SURE A+
✔✔Indications for a pacemeker - ✔✔-symptomatic patient
-heart rate less than 40 bpm
-asystole greater than 3 sec
✔✔Slew Rate - ✔✔peak slope of an electrogram signal (voltage/time) (dV/dt)
✔✔when is slew rate significant? - ✔✔when there are low amplitude intrinsic signals
✔✔range slew rate should be in atrium - ✔✔>0.3 v/s
✔✔range slew rate should be in ventricle - ✔✔>0.5 v/s
✔✔Pacing thresholds may ________ when sleeping and ________ when awake - ✔✔-
increase
-decrease
✔✔steroid eluting electrodes - ✔✔-corticosteroid dexamethasone sodium phosphate
impregnated in a silicone core
-acute threshold phase is relatively flat
-initial capture threshold is similar to non steroid eluting
, ✔✔pros to silicone pacemaker lead insulation - ✔✔-easily repaired
-flexible
-proven performance
-easy to make
✔✔cons to silicone pacemaker lead insulation - ✔✔-high friction coefficient
-absorbs lipids
-more thrombogenic and fibrotic
-cuts easily
-tears with suture if too tight
-larger diameter
✔✔pros to polyurethane pacemaker lead insulation - ✔✔-relatively
thronbogenetic/fibrotic
-thin walls
-high tear strength
-resists cutting
-low friction coefficient
-abrasion resistant
✔✔cons to polyurethane pacemaker lead insulation - ✔✔-not reparable
-relatively stiff
-hard to make
✔✔Why is polyurethane 80A bad for pacemaker leads? - ✔✔it would biodegrade and
cause insulation issues
✔✔What type pf polyurethane is good for pacemaker leads? - ✔✔55D
✔✔Pacemaker syndrome - ✔✔combination of symptoms occuring with v-pacing that are
relieved by restoring AV synchrony (experienced by 25% of vpaced patients to a degree
✔✔fallback - ✔✔-purpose is to avoid rapid and prolonged vpacing during atrial
arrhythmias
-decouples A and V at upper rate limit
✔✔rate smoothing - ✔✔eliminates large beat to beat variations by not letting pacing
rate change more than a certain percentage from the next interval
✔✔Percent change for rate smoothing in guidant devices - ✔✔3,6,12.5,25
✔✔Rate smoothing - ✔✔looks at last r-r interval and doesn't let the next change by
more than the programmed percentage
