CCDS Exam Study Guide (2026)
Everything the IBHRE Certified Cardiac Device Specialist (CCDS) Exam tests, topic by topic: what each section covers, the facts that come up most, and how to study it. Pair it with the free 15-question practice test.
The exam at a glance
| Questions | 200 multiple-choice questions in 4 timed sections |
|---|---|
| Time | 4 hours (240 minutes), with 6-minute breaks between sections; you can't return to a finished section |
| Passing score | Not published. IBHRE sets a criterion-referenced cut score and reports a scaled score; practise to 75% or higher |
| Format | Closed book, computer-based (on-screen calculator and calipers provided) |
| Certifying body | International Board of Heart Rhythm Examiners (IBHRE) |
| Test provider | PSI test centers in North America and internationally (no remote option listed by IBHRE) |
Mind map: the whole exam on one screen
Read the complete CCDS study notes for “Electrophysiology and Engineering Fundamentals”
Our first full set of comprehensive notes, about 15 minutes of reading: The conduction system, in order · Ohm's law and its relatives · The strength-duration curve · Batteries, capacitors and circuits · Leads and connectors, a worked exam example, the traps examiners use and a one-minute recap. Create a free account to read it and see how premium notes work before you decide.
1. Electrophysiology and Engineering Fundamentals
Domains 1 and 2 (13% together): conduction system anatomy, arrhythmia mechanisms, and the electrical and engineering basics behind every device: Ohm's law, strength-duration, batteries, capacitors, leads and connectors.
Key facts
- Conduction: sinus node → atrial tissue (Bachmann's bundle to the LA) → AV node → His bundle → bundle branches → Purkinje fibers.
- Ohm's law: V = I × R. Energy (joules) = V × I × pulse width = V² × pulse width ÷ R.
- Strength-duration curve: rheobase is the lowest voltage that captures at a very long pulse width; chronaxie is the pulse width at twice rheobase, where energy threshold is near its lowest.
- All modern devices use lithium batteries. Lithium-iodine is the classic low-drain pacemaker chemistry; ICDs need higher-current chemistries (for example lithium silver vanadium oxide, alone or in hybrids) to charge their high-voltage capacitors.
- Leads: silicone and polyurethane (or hybrid) insulation; coaxial, cable or coradial conductors; IS-1, DF-1, DF4 and IS4/LV-4 connectors; active or passive fixation; steroid elution lowers the acute threshold rise.
- Defibrillation: biphasic waveforms; the defibrillation threshold (DFT) is the lowest energy that reliably defibrillates. S-ICD and extravascular ICD systems use non-transvenous vectors.
Flashcards
Exam tip: Most calculation questions are Ohm's law in disguise. Write V = I × R on your laminated sheet before the clock starts.
2. Sensing, Stimulation and Timing Cycles
Domain 3 (10%): intracardiac signals and how they're sensed, capture and the acute-to-chronic threshold shift, the NBG code, single- and dual-chamber timing, rate modulation, CRT, leadless timing and upper-rate behavior.
Key facts
- NBG code: 1st letter chamber paced, 2nd chamber sensed, 3rd response to sensing (I inhibited, T triggered, D both), 4th R = rate modulation, 5th multisite pacing.
- Sensitivity is a threshold in mV: a lower number means more sensitive. Oversensing → raise the number; undersensing → lower it.
- Ventricular-based timing: VA interval = lower rate interval − AV delay. Atrial-based timing keeps the A-A interval fixed.
- Total atrial refractory period (TARP) = AV delay + PVARP. 2:1 block rate = 60,000 ÷ TARP.
- Between the upper tracking rate and the 2:1 rate, a DDD device shows pacemaker Wenckebach: AV delays lengthen until a P wave falls in PVARP.
- Rate modulation uses accelerometers, minute ventilation (thoracic impedance) or closed-loop impedance sensors.
- Thresholds rise over the first weeks after implant (acute-to-chronic shift), then settle; steroid elution blunts the peak.
Flashcards
Exam tip: Draw the timing cycle as a line with marks for AV delay, PVARP and the lower rate interval. Most timing questions solve themselves on paper.
3. Device Functions and Algorithms
Domain 4 (14%): bradycardia features (mode switching, rate hysteresis, automatic capture, minimizing RV pacing), tachycardia detection and therapy (zones, SVT discriminators, ATP, shocks), CRT programming and conduction system pacing.
Key facts
- Mode switching moves from a tracking mode (DDD) to a non-tracking mode (DDI or VDI) during atrial tachyarrhythmias so fast atrial rates aren't tracked.
- PMT: a retrograde P wave outside PVARP is tracked, and the loop repeats at or near the upper tracking rate. Prevent with a PVARP longer than retrograde VA time or a PMT algorithm.
- Algorithms that reduce RV pacing (managed ventricular pacing, AV search hysteresis) protect against pacing-induced cardiomyopathy.
- ICD detection uses rate zones and a duration or number-of-intervals criterion; SVT discriminators (morphology, onset, stability, AV relationship) are applied in the VT zone.
- ATP (burst or ramp) terminates many monomorphic VTs painlessly by entering the excitable gap of the reentry circuit.
- CRT aims for near-100% biventricular pacing; loss of BiV pacing from AF, PVCs or a long AV delay reduces benefit. His bundle and left bundle branch area pacing are conduction system alternatives.
Flashcards
Exam tip: For each algorithm, learn what problem it solves and the side effect it can cause. Pseudo-malfunction questions test the side effect.
Test yourself on these topics
Take the free 15-question CCDS test, then save your results to unlock your Readiness Score and the mistakes bank.
4. ECG, Paced Rhythms and Radiology
Domains 5 and 9 (14% together): reading paced ECGs and device malfunction, pseudo-malfunction, native and device-mediated arrhythmias, wearable monitor data, and chest X-ray, fluoroscopy, CT and echo findings.
Key facts
- RV apical pacing: LBBB pattern, superior axis. RVOT pacing: LBBB pattern, inferior axis. LV or BiV pacing: often a dominant R in V1.
- Selective His pacing gives a QRS identical to the intrinsic one, with an isoelectric interval after the spike; non-selective His and LBBAP show local myocardial capture too.
Flashcards
Exam tip: Before calling a malfunction, list what programmed features could explain it. IBHRE likes pseudo-malfunction tracings.
5. Clinical Assessment and Implant Practice
Domains 6 and 7 (22% together): patient and device history, indications for pacemakers, ICDs, CRT and loop recorders, drug-device interactions, implant technique and testing, complications, infection prevention, radiation safety and choosing parameters for the indication.
Key facts
- 2018 ACC/AHA/HRS: acquired Mobitz II, high-grade or third-degree AV block not due to reversible causes warrants pacing regardless of symptoms; sinus node dysfunction is paced when symptoms correlate with bradycardia.
- Acceptable acute measurements: ventricular threshold under 1.0 V at 0.5 ms, R wave above 5 mV; atrial threshold under 1.5 V, P wave above 2 mV; impedance in the lead's normal range.
Flashcards
Exam tip: Indication questions follow the guideline wording. Watch for 'regardless of symptoms' versus 'when symptoms correlate'.
6. Safety: EMI, MRI and Advisories
Domain 8 (7%): radiation therapy, electromagnetic interference and electrosurgery, device-device interactions such as LVADs, MRI-conditional labeling and programming, cremation, and device advisories and recalls.
Key facts
- Electrosurgery can cause oversensing: pacing inhibition in pacemakers and inappropriate shocks in ICDs. Bipolar cautery and short bursts reduce the risk.
- Pacemaker-dependent patients with EMI expected near the device: program asynchronous pacing (or use a magnet if the device paces asynchronously with one). ICDs: suspend tachy therapies and monitor.
Flashcards
Exam tip: Safety answers almost always protect the dependent patient first: keep pacing going, prevent inappropriate shocks, and recheck after.
7. Follow-Up and Troubleshooting
Domain 10 (20%, the largest): interrogation and programming, battery and lead natural history, sensing and capture troubleshooting, stored episodes and diagnostics, complications such as Twiddler syndrome, and remote monitoring.
Key facts
- Impedance falling below about 200 Ω suggests an insulation breach; a sudden rise (often above 2,000 Ω) suggests conductor fracture or a loose set screw.
- Far-field R-wave oversensing on the atrial channel causes inappropriate mode switching; fix with a longer PVAB or less atrial sensitivity.
Flashcards
Exam tip: Troubleshoot in order: rhythm and EGMs, then thresholds and sensing, then impedance trend, then programming. Questions follow the same logic.
How to pass
- 200 questions in 240 minutes is 72 seconds each, but each section has its own hard time limit and you can't go back. Pace each section on its own.
- Follow-up management is the largest domain (20%). Expect tracings: oversensing, undersensing, loss of capture, upper-rate behavior and pseudo-malfunction.
- Know the timing-cycle arithmetic cold: VA interval, total atrial refractory period, 2:1 block rate, Ohm's law. These are fast points if you don't have to think.
- IBHRE gives you on-screen calipers and a calculator. Practise reading intervals on tracings with calipers, not just answering text questions.
Frequently asked questions
How long should I study for the CCDS exam?
Most working candidates need 4 to 8 weeks at 45 to 60 minutes a day. Book your exam once your Readiness Score has stayed at 80 or higher for about a week.
Can I take the CCDS exam online?
IBHRE lists only in-person delivery at PSI test centers in North America and internationally; it doesn't list a remote option. Format: closed book, computer-based (on-screen calculator and calipers provided). Check IBHRE's current exam information for the rules.
What score do I need to pass the CCDS exam?
Not published. IBHRE sets a criterion-referenced cut score and reports a scaled score; practise to 75% or higher. The exam has 200 multiple-choice questions in 4 timed sections and a time limit of 4 hours (240 minutes), with 6-minute breaks between sections; you can't return to a finished section.
What are the most tested topics?
The outline covers electrophysiology and engineering fundamentals, sensing, stimulation and timing cycles, device functions and algorithms, ecg, paced rhythms and radiology, clinical assessment and implant practice, safety: emi, mri and advisories, follow-up and troubleshooting. Use the free practice test to see which ones you need most.
The premium CCDS study path
Premium CCDS prep is studied one topic at a time. Each step starts with that topic's key notes and flashcard deck, then its own question sets of 25, so you master one topic before you move to the next. When every topic is strong, the 6 full mock exams show you're ready.
Your step-by-step study path
- 1Electrophysiology and Engineering Fundamentals9 key notes, 115 flashcards, then 450 practice questions in 18 sets of 25Notes free with an account
- 2Sensing, Stimulation and Timing Cycles9 key notes, 115 flashcards, then 425 practice questions in 17 sets of 25Premium
- 3Device Functions and Algorithms9 key notes, 115 flashcards, then 425 practice questions in 17 sets of 25Premium
- 4ECG, Paced Rhythms and Radiology9 key notes, 115 flashcards, then 425 practice questions in 17 sets of 25Premium
- 5Clinical Assessment and Implant Practice8 key notes, 115 flashcards, then 425 practice questions in 17 sets of 25Premium
- 6Safety: EMI, MRI and Advisories8 key notes, 115 flashcards, then 425 practice questions in 17 sets of 25Premium
- 7Follow-Up and Troubleshooting8 key notes, 110 flashcards, then 425 practice questions in 17 sets of 25Premium
- Final step: 6 full mock exams200 questions each, timed like test day. Pass them, then book your exam.Premium
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- 3,000 practice questions + 6 full mock exams per exam
- 800 flashcards + 60 key notes per exam, by topic, plus mind maps
- Spaced repetition + mistakes bank
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- Video lessons as they release
- Content updates during your access
- 5 bonuses: timing and values sheet, malfunction atlas, study planner and more
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Renews once a year until you cancel. We email you before each renewal. Cancel any time from your account; you keep access until the end of the year you've paid for.
Summarized from IBHRE's official candidate information and the rules cited, checked November 2026. Confirm current requirements with International Board of Heart Rhythm Examiners (IBHRE).