A rare case of transcutaneous pacing (TCP) with true electrical and mechanical capture

EMS is called to an assisted living facility for a 79 year old female who is found collapsed outside her apartment door.

On arrival, the staff is providing adequate chest compressions.

The cardiac monitor is attached.

transcutaneous pacing 1

The arrest rhythm is asystole.

Chest compressions are continued, an IV is initiated, and 1 mg of epinephrine is given.

transcutaneous pacing 2

Now there is a regular bradycardic rhythm without P-waves at a rate of 30.

The patient has a faint pulse but a blood pressure cannot be auscultated. The patient is prepared for transcutaneous pacing (TCP).

transcutaneous pacing 3

The computer is successfully identifying and marking the R-waves.

The pacer is set to 80 PPM and paramedics report capture at 110 mA.

transcutaneous pacing 4

The presence of broad T-waves indicates true electrical capture.

With this rhythm there are pulses that correspond with the monitor (not always accurate), there is an SpO2 waveform, and the NIBP is 118/68.

Unfortunately the patient did not survive to hospital discharge.

See also:

Transcutaneous Pacing (TCP): The Problem of False Capture

Revisiting Transcutaneous Cardiac Pacing

Transcutaneous Pacing Success!!! Part 1

Transcutaneous Pacing Success!!! Part 2

Transcutaneous Pacing: “Turn it up to eleven!”


  • Bill C. says:

    I’d agree with pacing it appears in the post arrest ECG that there is AV dissociation with an atrial rate of 150.

    The capture appears good since there is a nice wide QRS with ST-T going in the opposite direction of force of the QRS.

    To manage this patient I’d like to:
    -continue to monitor the EtCO2 (for a spike with ROSC and pacing capture or sudden decrease inidcating loss of capture or circulation),
    -transport to a PCI facility with an EP an lab for an eventual pacemaker insertion, and
    -provide pain management with 1 mcg/kg fentanyl every 5-10 minutes.

  • Tom B says:

    Bill –

    Great observations!

    The patient was still unconscious so no pain management was required.


  • Christopher says:

    Looks like capture, good QRS deflection at the appropriate distance from the pacer impulse, discordant T wave too.

    I’d like lead II, SpO2 waveform, and ETCO2 waveform on my monitor and printouts to help me “verify” capture and ensure continued capture. ECG criteria, radial pulses, SpO2 waveform matching, and ETCO2 evidence of perfusion should allll be used as one big happy diagnostic evidence family!

  • Troy H says:

    I agree with Chris.

    Sp02 capture and EtCO2 good waveform will definitely assist with pacing cature and possiblilty of mechanical non-capture with electrical capture.

    As far as the asystolic arrest and using a pacer, as far as what I’ve read its only while in asystole that you don’t pace. According to the 2010 guidelines, once you get ROSC you follow the post-arrest algorithm.

    As far as post-arrest, the 2010 guidelines state that although hypothermia is more successful with v-fib arrest, it is still recommended (because it has had good results) with asystolic/PEA ROSC. So I would go hypothermia with 1.5mg/kg (max 150mg) succinocholine for shivering or 5mg versed if needed. If hypotension occurs (MAP<70) start with 2L cold NS then move onto 10-20mcg/kg/min dopamine.

    Also I would want to know a BG level and a 12 lead. More or less with asystolic/PEA presenting arrest, I like to look for PE changes, hyperkalemia, hypervagalism, proximal LAD occlusion, sepsis, hypothermia and hypovolemia.

    If I'm mistaken on anything please correct me.

  • Kevin says:

    Why would one not consider atropine before TCP?

  • Chris T says:

    Pacing in asystole I am not a fan of, I will be happy not to have to do it.
    With the ROSC I agree to go to appropriate algorithm, this scenario I agree pacing was the apropriate treatment. I also try to remember to be patient with post arrest arrhythmias.

    I am not educated on induced hypothermia in ROSC at this point Troy, but impressive to have access to that equipment, education and medication as currently I understand it is providing best results. Very “cool”

  • Christopher says:

    Kevin, this was post-arrest so atropine would not necessarily be as useful. The patient’s bradycardia is probably not secondary to increased parasympathetic tone.

  • Troy says:

    Kevin, although atropine is now the first line drug in symptomatic bradycardia it is still not the greatest treatment for this patient. Because the patient is severely symptomatic, (AMS with low perfusion) TCP is your best initial bet. The problem with starting the pacing is that, if stopped, there is no guarantee that you will get capture again!!

    Plus, the patient is now a post-arrest patient with an obvious anoxic heart issue (seen with the arrhythmia and bradycardia). We cant control the effects the atropine has on the heart. The parasympatholytic actions will increase the oxygen demand on an already tired heart so why not just take over for the heart and let it kick back and relax?

    I’m not saying that atropine won’t work (although it probably wouldn’t) but more of the effects atropine has on the heart. TCP is safer in a post-arrest patient.

  • Jeff says:

    Depending on how fast IV access can be established vs. how fast tcp can be be initiated would play a role as to which would be better to try first. One factor which has not been mentioned is how long the Pt has been down. Was the collapse witnessed? This scenario states found down not witnessed collapse. Although unable to officially dx in the field, if total time of CPA is extensive and Pt has enough cerebral edema to constitute clinical brain death then the use of atropine without change in pulse may correlate the findings of brain death. Again…. This is definitely not something that we should be trying to dx in the field and requires an MD to dx but would be good information to relay to the ER staff and especially a neurological consult!

  • Scott says:

    I haven’t had a chance to read through all the comments, but as far as radial pulses go, I’d prefer something other than radials. The arms have a tendency to jerk when being paced and can cause false positives. Femoral pulses please. Obviously there’s a decent BP, but …

  • Rogue Medic says:

    This is not pacing for asystole.

    Defibrillation is not part of asystole treatment, but would any of us refuse to defibrillate a patient who goes from asystole to V Fib? I hope not.

    The amount of time it would take to initiate pacing vs. drug treatment is not important.

    This patient has already received 1 mg epinephrine, so an IV/IO is in place. We can safely assume that if the drugs had been given down the tube, the patient would still be pulseless, because giving dead people drugs down the tube is just silly.

    How long does it take to initiate pacing? Less than a minute.

    How long does it take to grab a drug and push it IV? Less than a minute, unless you want to mix a dopamine drip (that will depend on a lot of factors).

    Of course, any requirement for medical command permission only delays treatment.

    What kind of EtCO2 numbers are being produced with this rhythm that looks like capture? Do we have anything from before pacing was begun? Is there a significant increase in the EtCO2?

    I have cath labs all over the place, here in the home of the cheese steak,so destination is not a problem. I don’t have therapeutic hypothermia unless I work everything outside in the snow. 🙁

  • My understanding of pacing in asystole was that it is not recommended simply because it is usually ineffective. This is because the majority of time, asystole represents a confirmation of death rather than a workable rhythm.

    However, if I’m working a patient and they lapse into asystole, say, as a post-defibrillation rhythm, what’s the harm in pacing? I already have hands-free electrodes in place. All it takes is setting a rate and starting the current.

    If I achieve mechanical capture, at least some perfusion is generated. If I achieve only electrical capture at first, what is the harm as long as I don’t stop compressions?

  • Troy says:


    I live in Utah so in the winter time when we get ROSC and go down our therapeutic hypothermia treatment that means a “cold” run to the hospital with the windows down. lol. Pisses off some medics but thats what needs to be done right?

    Ambulance Driver,

    The reason pacing has been taken out of the asystole algorithm is because most of the time it is more harmful than good. I’ve heard some of the old timers tell me that they would pace asystole and have good capture but when they got to the hospital, somewhere in transport the mechanical capture went away.

    The fact is that asystole is the end stage of prolonged V-fib or PEA so there is generally no ATP left to feed the heart. Pretty much all your pacing is a depleted organ. I feel that CPR is the best treatment and an advanced airway quicker than V-fib.

    Do what you want but I just remember one guy coming into a hospital i was posted at and they brought in a full arrest with a 16 year old and were pacing him from asystole. Needless to say they weren’t getting actual mechanical capture. A nice big lawsuit followed for negligence for not following AHA guidlines.

    Personally I find it pretty dang hard to find mechanical capture when pacing. Maybe it’s just me…..

  • Troy says:

    One more thing….. Like rogue said I think meds down the tube is just silly, especially since some case studies have found epinephrine down the tube causes vasodilation! If you cant get an AC, go EJ. Actually literature supports that if you can get an EJ it is better than an AC in a full arrest. If the patient has a PICC, all the better! Suck out about 60mL of blood (to account for the heparin lock) and flow some drugs! The closer to the heart the better.

    The reason i see ET meds being gone soon is because of the easy access we have now through IO. It’s amazingly quick in a full arrest and sometimes is our first choice if the patient is a hard stick (i.e. cancer patients, morbid obesity). If you slam 20cc of fluid and break up the marrow it usually flows pretty good. If not, put the fluid in a pressure bag.

  • Mike says:

    Has Drugs via ET not gone already over there? New Resus Guidelines in the UK have taken ET out.

  • Jon says:

    You can just flush the hep lock, its only 300 units, withdrawing 60ml of blood is beyond ridiculous. about 4ml of blood is enough to clear out most drugs, 12 at the very max.

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