Implanted Cardiac Devices and Special Considerations Practice Questions

30 multiple-choice questions on Implanted devices and special considerations for paramedic and EMT students, from Chapter 18 (Cardiovascular Emergencies). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

30 practice questions

1. A 12-lead from a patient with a ventricular pacemaker shows a pacer spike before each wide QRS. Which QRS pattern is typical with right ventricular pacing?

   1. A. A left bundle branch block pattern
   2. B. A right bundle branch block pattern
   3. C. A narrow QRS less than 0.08 seconds
   4. D. A delta wave with a short PR interval
   Show answer

   Answer: A. A left bundle branch block pattern

   Pacing from the right ventricular apex depolarizes the left ventricle last, producing a wide QRS that resembles LBBB. This makes STEMI recognition harder.

2. A patient says she has a pacemaker, but you find no generator bump or chest scar. The monitor shows a paced rhythm. What is the most likely explanation?

   1. A. The monitor is showing artifact from the leads
   2. B. Her pacemaker was probably removed long ago
   3. C. A leadless pacemaker placed inside the heart
   4. D. She is confusing a pacemaker with a stent
   Show answer

   Answer: C. A leadless pacemaker placed inside the heart

   Leadless pacemakers are small capsules placed inside the right ventricle through a leg vein, so there is no generator pocket or chest scar, yet they pace like other devices. A paced rhythm on the monitor argues against artifact or removal, and a stent does not produce pacing spikes.

3. A pacemaker fires spikes that fall on or near T waves even though the patient's native rate is 90. This is:

   1. A. Failure to capture
   2. B. Failure to sense
   3. C. Failure to pace
   4. D. Normal capture
   Show answer

   Answer: B. Failure to sense

   Failure to sense (undersensing) means the device does not detect intrinsic beats and fires inappropriately, sometimes on the T wave, which can trigger VT or VF.

4. A patient with a pacemaker has a heart rate of 32 and no pacer spikes on the monitor. Which problem is most likely?

   1. A. Failure to capture
   2. B. Failure to pace
   3. C. Pacemaker runaway
   4. D. Normal sensing
   Show answer

   Answer: B. Failure to pace

   No output from the device despite a slow intrinsic rate suggests failure to pace, from battery failure, lead break, or oversensing. Treat symptomatic bradycardia per ACLS, including transcutaneous pacing.

5. A hospice patient with a DNR order is actively dying, and her ICD has shocked her several times, upsetting the family. What is the most appropriate action?

   1. A. Ask medical direction about a magnet on the ICD
   2. B. Start CPR, since the ICD has detected an arrest
   3. C. Cut the ICD out to stop the shocks right now
   4. D. Tell the family nothing can be done about it
   Show answer

   Answer: A. Ask medical direction about a magnet on the ICD

   Repeated ICD shocks at the end of life cause distress; with medical direction or per protocol, placing a magnet over most ICDs suspends shock therapy while it stays in place, consistent with the patient's goals of care. Starting CPR conflicts with the DNR, and a shock does not mean arrest, removing the device is not a field procedure, and telling the family nothing can be done is wrong.

6. A patient with an ICD is in VF, and you see his body jerk as the ICD fires. What should you do?

   1. A. Start CPR and use your defibrillator
   2. B. Wait 10 minutes for the ICD to finish
   3. C. Withhold CPR to avoid an ICD shock
   4. D. Place a magnet and withhold any shocks
   Show answer

   Answer: A. Start CPR and use your defibrillator

   Treat the arrest normally. If the ICD fires during CPR, a rescuer may feel a mild tingle but is not harmed, especially with gloves. If you are ready to shock, do not wait for the ICD.

7. A conscious patient with an ICD has received six shocks in the past hour and is anxious. The monitor shows sinus tachycardia at 118. What is the most likely concern?

   1. A. Normal ICD function here
   2. B. Expected pacemaker capture
   3. C. Inappropriate ICD shocks
   4. D. Hyperkalemia alone
   Show answer

   Answer: C. Inappropriate ICD shocks

   Repeated shocks during a non-life-threatening rhythm suggest inappropriate firing, often from lead failure or sensing of sinus tachycardia or AF. Per protocol and medical direction, a magnet may suspend shocks.

8. What effect does placing a magnet over most ICDs have?

   1. A. It delivers one test shock
   2. B. It turns off pacing therapy
   3. C. It sets fixed-rate pacing
   4. D. It suspends shock therapy
   Show answer

   Answer: D. It suspends shock therapy

   On most ICDs a magnet temporarily disables tachyarrhythmia detection and shocks while it is in place; bradycardia pacing usually continues. Use only per protocol or medical control. Fixed-rate pacing is a pacemaker's magnet response, an ICD magnet does not deliver a test shock, and it does not turn off bradycardia pacing.

9. Placing a magnet over a standard pacemaker generally causes it to:

   1. A. Stop pacing completely at once
   2. B. Deliver a defibrillation shock
   3. C. Pace at a fixed rate without sensing
   4. D. Pace only at the native rate
   Show answer

   Answer: C. Pace at a fixed rate without sensing

   A magnet over most pacemakers switches them to asynchronous fixed-rate pacing, ignoring intrinsic beats. This is mainly used in hospital for troubleshooting or during surgery.

10. A man with a ventricular pacemaker has 30 minutes of crushing chest pain. His 12-lead shows a paced rhythm. Why is reading the 12-lead for ischemia harder?

    1. A. A pacemaker keeps heart attacks from happening
    2. B. Paced rhythms show ST elevation in most leads
    3. C. The ECG cannot be recorded with a pacemaker
    4. D. Paced beats can hide or mimic ischemic changes
    Show answer

    Answer: D. Paced beats can hide or mimic ischemic changes

    Ventricular pacing produces wide QRS complexes with secondary ST-T changes, similar to left bundle branch block, which can hide or mimic ischemia; special criteria (such as Sgarbossa) are used, so transmit the ECG, treat the patient clinically and consult. Pacemakers do not prevent MI, they do not produce universal ST elevation, and a 12-lead can still be recorded.

11. How can you confirm that an LVAD is running?

    1. A. Listen over the device for a hum
    2. B. Palpate the carotid pulse firmly
    3. C. Check SpO2 on the patient's finger
    4. D. Look for pacer spikes on the ECG
    Show answer

    Answer: A. Listen over the device for a hum

    A continuous mechanical hum over the left upper abdomen or chest indicates the pump is running. The controller display and alarms give additional information.

12. Which method is most reliable for estimating BP in an LVAD patient in the field?

    1. A. Doppler with a manual cuff
    2. B. Automated cuff on the arm
    3. C. Palpating a radial pulse
    4. D. Capillary refill testing
    Show answer

    Answer: A. Doppler with a manual cuff

    With continuous flow, automated cuffs often fail. The pressure at which a Doppler signal returns approximates the MAP; many programs target roughly 60 to 90 mm Hg.

13. An LVAD patient's controller is alarming for low power. What is the most appropriate action?

    1. A. Disconnect both batteries together
    2. B. Change one power source at a time
    3. C. Silence the alarm and transport
    4. D. Switch the controller off and on
    Show answer

    Answer: B. Change one power source at a time

    Disconnecting both power sources at once stops the pump. Change one battery at a time or connect to wall power, and bring the patient's backup equipment and batteries.

14. Who is the best resource when caring for an LVAD patient with a device problem?

    1. A. The nearest cardiology clinic
    2. B. The device's online user forum
    3. C. The patient's VAD coordinator
    4. D. Any available on-call surgeon
    Show answer

    Answer: C. The patient's VAD coordinator

    LVAD patients carry the phone number of their implanting center's VAD coordinator, who can guide troubleshooting. Transport to the implanting center when possible.

15. An LVAD patient is unresponsive and apneic. The pump is not humming, and there are no signs of perfusion. Per current AHA guidance, what is reasonable?

    1. A. Fix the pump before starting CPR
    2. B. Shock first, then assess flow
    3. C. Start chest compressions
    4. D. Wait for coordinator call
    Show answer

    Answer: C. Start chest compressions

    An AHA scientific statement supports chest compressions when an LVAD patient is unresponsive with no evidence of perfusion. Attempt to restart or fix the device in parallel if trained. Do not delay compressions to fix the pump or to wait for the coordinator, and shocks are given only for a shockable rhythm.

16. Can an LVAD patient in VF be defibrillated?

    1. A. No, the shock will destroy the pump motor
    2. B. Yes, using standard pad placement and energy
    3. C. Only after the LVAD has been switched off
    4. D. Only with half the standard energy setting
    Show answer

    Answer: B. Yes, using standard pad placement and energy

    Defibrillation is safe in LVAD patients and does not require disconnecting the device. Some patients tolerate VT or VF while the LVAD maintains flow, but unstable rhythms should still be treated.

17. A patient wears a vest-like device under his shirt that he says can shock his heart. What is this device?

    1. A. An external transcutaneous pacer unit
    2. B. A Holter monitor with ECG recording
    3. C. An implantable loop recorder device
    4. D. A wearable cardioverter-defibrillator
    Show answer

    Answer: D. A wearable cardioverter-defibrillator

    Wearable cardioverter-defibrillators detect VT/VF and deliver shocks. A conscious patient can press response buttons to abort an unnecessary shock. Remove it before using your own defibrillator if it is in the way.

18. A pacemaker that paces both the right and left ventricles to coordinate contraction in heart failure is called:

    1. A. Single-chamber atrial-only pacing
    2. B. Asynchronous ventricular pacing
    3. C. Cardiac resynchronization therapy
    4. D. Transvenous temporary pacing
    Show answer

    Answer: C. Cardiac resynchronization therapy

    Biventricular pacing (CRT) helps the ventricles contract together in patients with heart failure and wide QRS. Many CRT devices also include a defibrillator.

19. A dual-chamber pacemaker typically shows which ECG pattern when pacing both chambers?

    1. A. One spike before each wide QRS and no atrial spike
    2. B. No visible spikes on any lead at any time
    3. C. A single spike before each P wave
    4. D. A spike before the P and another before the QRS
    Show answer

    Answer: D. A spike before the P and another before the QRS

    Dual-chamber (AV sequential) pacing produces an atrial spike followed by a P wave and a ventricular spike followed by a wide QRS. A spike before the QRS alone is single-chamber ventricular pacing, a spike before the P wave alone is atrial pacing, and dual-chamber pacing does produce visible spikes.

20. An LVAD patient has dark, tea-colored urine and a 'high power' alarm on his controller. He is fatigued. What complication should you suspect?

    1. A. A clot forming inside the pump
    2. B. Low blood volume from not drinking
    3. C. A normal reading after a heavy meal
    4. D. A dead battery in the controller
    Show answer

    Answer: A. A clot forming inside the pump

    Pump thrombosis increases the power the motor draws and damages red cells, producing hemolysis with dark urine; it can cause pump failure, so contact the VAD team and transport to the implanting center. Low volume causes low-flow alarms, a high power alarm is not normal after meals, and a dead battery causes a low-power alarm.

21. A patient with a new pacemaker has had constant hiccups and abdominal twitching since yesterday, in time with the pacing spikes. What is the likely cause?

    1. A. A normal effect of a newly placed pacemaker
    2. B. The lead is stimulating the diaphragm
    3. C. A pocket infection around the generator
    4. D. Low calcium causing muscle spasm
    Show answer

    Answer: B. The lead is stimulating the diaphragm

    Hiccups or abdominal twitching that match the paced beats suggest that the lead has moved or the output is stimulating the phrenic nerve or diaphragm; the device needs prompt evaluation. It is not a normal effect, an infection causes redness and swelling at the pocket, and low calcium causes spasm that does not track with the pacing rhythm.

22. A 70-year-old has a pacemaker and complains of dizziness, fatigue, and pulsations in the neck. ECG shows ventricular pacing with retrograde P waves. This is most consistent with:

    1. A. Pacemaker runaway
    2. B. Pacemaker infection
    3. C. Lead fracture
    4. D. Pacemaker syndrome
    Show answer

    Answer: D. Pacemaker syndrome

    Pacemaker syndrome results from loss of AV synchrony, usually with ventricular-only pacing, causing atrial contraction against closed valves, reduced output, and neck pulsations.

23. A patient with a pacemaker presents with fever, redness, swelling, and drainage at the generator site. What should you suspect?

    1. A. Normal post-implant healing
    2. B. Device pocket infection
    3. C. Pacemaker battery failure
    4. D. Superficial contact allergy
    Show answer

    Answer: B. Device pocket infection

    Redness, swelling, warmth, and drainage at the generator site suggest pocket infection, which can spread to leads and cause endocarditis or sepsis.

24. A patient with an ICD reports a single shock 2 hours ago and now feels well with stable vital signs. What is generally recommended?

    1. A. No follow-up is ever needed after one shock
    2. B. Evaluation per protocol or by the device team
    3. C. Immediate CPR because a shock was given
    4. D. Applying a magnet for the next 24 hours
    Show answer

    Answer: B. Evaluation per protocol or by the device team

    Even a single shock warrants contact with the device clinic or medical evaluation, depending on local protocol. Multiple shocks, chest pain, or syncope require emergency evaluation.

25. Your patient with an LVAD has a low-flow alarm, cool skin, and altered mental status. Which cause should be considered?

    1. A. A dead spare battery in the bag
    2. B. Hypovolemia or bleeding
    3. C. Too much IV fluid given
    4. D. Elevated blood glucose
    Show answer

    Answer: B. Hypovolemia or bleeding

    LVADs depend on adequate preload; volume depletion, GI bleeding (common due to anticoagulation), RV failure, or thrombosis can cause low flow. Small fluid boluses may be indicated per protocol. A spare battery that is not in use cannot change pump flow, excess fluid raises rather than lowers preload, and glucose does not cause a low-flow alarm.

26. Why are LVAD patients at increased risk of bleeding?

    1. A. They take high-dose steroids
    2. B. They have a lower blood volume
    3. C. The device raises their BP
    4. D. They take anticoagulants
    Show answer

    Answer: D. They take anticoagulants

    LVAD patients take anticoagulation and antiplatelet agents to prevent pump thrombosis, raising the risk of GI and intracranial bleeding. Shear stress in the pump can also impair platelets and break down von Willebrand factor, but steroids are not part of standard LVAD therapy, blood volume is not lower, and the device does not raise BP.

27. When transporting an LVAD patient, what equipment should accompany the patient?

    1. A. Spare charged batteries but no backup controller
    2. B. The backup controller and spare batteries
    3. C. The bedside monitor and its cables
    4. D. The home wall charger with no batteries
    Show answer

    Answer: B. The backup controller and spare batteries

    Always bring the backup controller, spare charged batteries, and power cables, plus the patient's emergency guide, so device problems can be fixed during transport or at the hospital. Batteries without the backup controller, a bedside monitor or a wall charger without batteries cannot keep the pump running if the controller fails.

28. A paramedic is treating a patient whose ICD fires while the paramedic is touching the patient's chest. What is the expected effect on the rescuer?

    1. A. Cardiac arrest in most cases
    2. B. A full 200 J shock to hands
    3. C. Burns to the rescuer's hands
    4. D. A mild tingle without harm
    Show answer

    Answer: D. A mild tingle without harm

    ICD shocks deliver small energy (often up to about 40 J) internally, and little reaches the skin. Rescuers may feel a mild tingle; gloves add protection.

29. A patient with a transvenous permanent pacemaker is in symptomatic bradycardia with failure to capture. What is the appropriate field treatment?

    1. A. Apply a magnet and wait for capture
    2. B. Treat it as PEA and begin CPR
    3. C. Treat per ACLS, including TCP
    4. D. Synchronized cardioversion at 50 J
    Show answer

    Answer: C. Treat per ACLS, including TCP

    Failure of an implanted pacemaker is treated like any symptomatic bradycardia: atropine (often ineffective), transcutaneous pacing, or chronotropic infusion per ACLS and protocol. He has a pulse, so PEA care and CPR do not apply, cardioversion is for tachycardias, and a magnet makes most pacemakers pace asynchronously but does not fix loss of capture.

30. A man with a pacemaker becomes dizzy each time he leans over a running car engine to work on it, and feels fine when he steps away. What is the likely cause?

    1. A. Carbon monoxide poisoning from the engine exhaust
    2. B. Electromagnetic interference inhibiting pacing
    3. C. A pacemaker battery that is fully drained today
    4. D. Low blood sugar from skipping his meals at his work
    Show answer

    Answer: B. Electromagnetic interference inhibiting pacing

    Strong electromagnetic fields, such as those near a running engine's alternator or ignition system, can be sensed by a pacemaker as heartbeats and inhibit pacing, causing dizziness that resolves when he moves away; patients are advised to keep such sources away from the device. CO poisoning, a drained battery and low blood sugar would not stop as soon as he steps away.