CCDS IBHRE Exam Questions & Answers 2023/2024
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 (fo...
CCDS IBHRE Exam Questions & Answers 2023/2024
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)
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 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.
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
NOTE: Pt may be asymptomatic with 2 or 3
Slew Rate - ANSWER-Slew rate = peak slope of an electrogram slew rate= change in voltage/ change in time
Normal slew rate in atrium - ANSWER->.3 V/s
Normal slew rate in ventricle - ANSWER->.5V/s
Steroid used in electrodes - ANSWER-dexamethasone sodium phosphate in the silicone core(a corticosteriod)
Steroid-Eluting Electrodes - ANSWER-1. The acute threshold is relatively flat compared to non-steroid electrodes
2. The initial capture threshold is similar to non-steroid leads
Silicone Rubber lead insulation Pros - ANSWER-1. Can easily be repaired
2. Flexible
3. Proven performance history
4. Easy to make
Silicone Rubber lead insulation cons - ANSWER-1. high friction coefficient
2. Absorbs lipids
3. More thrombogenic and fibrotic
4. Cuts easily
5. Tears easily if suture tied too tightly
6. Large diameter
Polyurethane 80A - ANSWER-BAD
Polyurethane 55D - ANSWER-GOOD polyurethane lead insulation pros - ANSWER-1. relatively nonthrombogenic/fibrotic 2. thin walls
3. high tear friction
4. resists cutting
5. low friction coefficient
polyurethane lead insulation cons - ANSWER-1. cannot be repaired 2. relatively stiff
3. hard to make
Pacemaker Syndrome Causes - ANSWER-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 - ANSWER-1. Observe fluctuation in the peripheral blood pressure
2. Cannon "A" wave in the neck
3. History alone
Pacemaker syndrome management - ANSWER-Restore AV synchrony
in ventricular only PM -->lower the pacing rate to minimize ventricular only pacing DO NOT increase the pacing rate
Fallback - ANSWER-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
Les avantages d'acheter des résumés chez Stuvia:
Qualité garantie par les avis des clients
Les clients de Stuvia ont évalués plus de 700 000 résumés. C'est comme ça que vous savez que vous achetez les meilleurs documents.
L’achat facile et rapide
Vous pouvez payer rapidement avec iDeal, carte de crédit ou Stuvia-crédit pour les résumés. Il n'y a pas d'adhésion nécessaire.
Focus sur l’essentiel
Vos camarades écrivent eux-mêmes les notes d’étude, c’est pourquoi les documents sont toujours fiables et à jour. Cela garantit que vous arrivez rapidement au coeur du matériel.
Foire aux questions
Qu'est-ce que j'obtiens en achetant ce document ?
Vous obtenez un PDF, disponible immédiatement après votre achat. Le document acheté est accessible à tout moment, n'importe où et indéfiniment via votre profil.
Garantie de remboursement : comment ça marche ?
Notre garantie de satisfaction garantit que vous trouverez toujours un document d'étude qui vous convient. Vous remplissez un formulaire et notre équipe du service client s'occupe du reste.
Auprès de qui est-ce que j'achète ce résumé ?
Stuvia est une place de marché. Alors, vous n'achetez donc pas ce document chez nous, mais auprès du vendeur Bensuda. Stuvia facilite les paiements au vendeur.
Est-ce que j'aurai un abonnement?
Non, vous n'achetez ce résumé que pour €10,20. Vous n'êtes lié à rien après votre achat.
