Exam (elaborations)
CCDS IBHRE Exam Review
- Course
- Institution
CCDS IBHRE Exam Review CCDS IBHRE Exam Review CCDS IBHRE Exam Review
[Show more]
Content preview
CCDS IBHRE Exam ReviewRheobase - CORRECT ANS the lowest point on a strength duration curve at an infinitely long pulse
duration
Chronaxie time - CORRECT ANS the pulse width at twice the rheobase value. It approximates the most
efficient stimulation pulse duration
Charge (formula) - CORRECT ANS Charge= I(current) x T(time)
Furman's formula - CORRECT ANS Energy(microjoules)= I(current)xV(voltage)xT(pulse width)
Ohms law formula - CORRECT ANS Voltage(electromotive force)= I(current/flow of electrons) x
R(resistance to current flow in ohms)
Functional Refractory Period - CORRECT ANS the coupling interval which first results in a measurable
degree of delay in impulse conduction
Effective Refractory Period - CORRECT ANS the longest coupling interval to be associated with block
Devices with NO interaction with pacers - CORRECT ANS 1. microwave oven, 2. CT scan/Ultrasound 3. X-
rays (diagnostic)
Devices that cause transient or 1 beat inhibition - CORRECT ANS 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 - CORRECT ANS 1. MRI 2. Defibrillator 3. Cardioversion 4.
Cautery/RF Ablation 5. Radiation Therapy
,Resistance in Series - CORRECT ANS 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 - CORRECT ANS 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? - CORRECT ANS ALL permanent
pacemakers are constant voltage devices.
SOME temp pacemakers are constant voltage, most are constant current.
LOAD - CORRECT ANS 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 - CORRECT ANS 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 - CORRECT ANS Slew rate = peak slope of an electrogram
slew rate= change in voltage/ change in time
Normal slew rate in atrium - CORRECT ANS >.3 V/s
Normal slew rate in ventricle - CORRECT ANS >.5V/s
Steroid used in electrodes - CORRECT ANS dexamethasone sodium phosphate in the silicone core(a
corticosteriod)
Steroid-Eluting Electrodes - CORRECT ANS 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 - CORRECT ANS 1. Can easily be repaired
2. Flexible
3. Proven performance history
4. Easy to make
Silicone Rubber lead insulation cons - CORRECT ANS 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 - CORRECT ANS BAD
Polyurethane 55D - CORRECT ANS GOOD
polyurethane lead insulation pros - CORRECT ANS 1. relatively nonthrombogenic/fibrotic
2. thin walls
3. high tear friction
4. resists cutting
5. low friction coefficient
polyurethane lead insulation cons - CORRECT ANS 1. cannot be repaired
2. relatively stiff
3. hard to make
Pacemaker Syndrome Causes - CORRECT ANS 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 - CORRECT ANS 1. Observe fluctuation in the peripheral blood pressure
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller lectjoseph. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
81633 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now