The major ECG rhythms classified as bradycardia include:
- -Sinus Bradycardia
- -First-degree AV block
- -Second-degree AV block
- -Type I —Wenckebach/Mobitz I
- -Type II —Mobitz II
- -Third-degree AV block complete block
Bradycardia vs. Symptomatic Bradycardia
Bradycardia is defined as any rhythm disorder with a heart rate less than 60 beats per minute. (Usually less than 60)
Symptomatic bradycardia, however, is defined as a heart rate less than 60/min that elicits signs and symptoms, but the heart rate is typically less than 50/min.
Symptomatic bradycardia exists when the following 3 criteria are present: 1.) The heart rate is slow; 2.) The patient has symptoms, and 3.) The symptoms are due to the slow heart rate.
Relative bradycardia occurs when a patient may have a heart rate within normal sinus range, but the heart rate is insufficient for the patient’s condition. An example would be a patient with a heart rate of 80 bpm when they are experiencing septic shock.
Bradycardia Pharmacology
There are 3 medications that are used in the Bradycardia ACLS Algorithm. They are atropine, dopamine (infusion), and epinephrine (infusion). More detailed ACLS pharmacology information is reviewed following this page.
- The single dose administration of atropine was increased from 0.5 mg to 1 mg. Now give 1 mg for the first dose and then repeat every 3-5 minutes at the 1 mg dose.
- Also, the dopamine infusion rate for chemical pacing was changed to 5-20 mcg/kg/min.
The previous rate from the 2015 guidelines was 2-20 mcg/kg/min. - The demand rate may be set at a range from 60-80/min. 2015 guidelines had the start demand rate to start at only 60/min.
2015 AHA Update: For symptomatic bradycardia or unstable bradycardia IV infusion a chronotropic agent (dopamine & epinephrine) is now recommended as an equally effective alternative to external pacing when atropine is ineffective.
Atropine: The first drug of choice for symptomatic bradycardia. The dose in the bradycardia ACLS algorithm is 1 mg IV push and may repeat every 3-5 minutes up to a total dose of 3 mg.
Dopamine: Second-line drug for symptomatic bradycardia when atropine is not effective. Dosage is 5-20 micrograms/kg/min infusion.
Epinephrine: Can be used as an equal alternative to dopamine when atropine is not effective. Dosage is 2-10 micrograms/min.
Bradycardia Algorithm
The decision point for ACLS intervention in the bradycardia algorithm is determination of adequate perfusion. For the patient with adequate perfusion, observe and monitor the patient. If the patient has poor perfusion, preparation for transcutaneous pacing should be initiated, and an assessment of contributing causes (H’s and T’s) should be carried out.
Click below to view the bradycardia algorithm diagram. When finished, click again to close the diagram.
Bradycardia Algorithm Diagram
or Download the High Resolution PDF Here. (This will open in another window.)
Transcutaneous pacing (TCP)
Preparation for TCP takes place as atropine is being given. If atropine fails to alleviate symptomatic bradycardia, TCP is initiated. Ideally, the patient receives sedation prior to pacing, but if the patient is deteriorating rapidly, it may be necessary to start TCP prior to sedation.
For the patient with symptomatic bradycardia with signs of poor perfusion, transcutaneous pacing is the treatment of choice.
Do not delay TCP for the patient with symptomatic bradycardia with signs of poor perfusion. The starting rate for TCP is 60-80/min and adjust up or down based on the patient’s clinical response. The dose for pacing is set at 2mA (milliamperes) above the dose that produces observed capture.
TCP is contraindicated in the patient with hypothermia and is not a recommended treatment for asystole.
Do not use a carotid pulse check for the assessment of circulation as TCP can create muscular movements that may feel like a carotid pulse. Assess circulation using the femoral pulse.
Identification of contributing factors for symptomatic bradycardia should be considered throughout the ACLS protocol since reversing of the cause will likely return the patient to a state of adequate perfusion.
Top Questions Asked on This Page
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Q: Should I use atropine in all cases of symptomatic bradycardia regardless of the level of block? The prep test for AHA ACLS seems to support giving atropine initially in symptomatic second-degree block type II, but not for complete block.
A: There are a couple of things to mention here. First, atropine may be used for any type of block but may negatively affect outcomes if the bradycardia is being caused by myocardial infarction.
This negative effect may occur because atropine increases the heart rate and myocardial oxygen demand. In the case of bradycardia caused by MI, it would be safer to transcutaneous pace (TCP) at a rate of 60 and move toward some type of cardiac intervention. You should use the 12 lead ECG to help determine MI. This will help determine if atropine may exacerbate the patient’s condition. If the patient has severe symptoms, you should not delay transcutaneous pacing (TCP).
You will usually have time to try atropine as you prepare for TCP.
Second, AHA states “For Mobitz II and complete block (3rd Degree block), atropine should not be relied upon.” This does not mean that it is contraindicated. It just means that it should not be relied upon because there is a good chance that it will not work.
It may not work because atropine blocks the action of the vagus nerve. Atropine works at the SA and AV node through its effect on the vagus nerve, and since conduction abnormalities associated with 2nd-degree block type II and 3rd-degree heart block are below (distal) the site of action for atropine, the drug will typically have an insignificant effect.
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Q: Why is pacing contraindicated in hypothermia?
A: Bradycardia may be physiologic in the hypothermic patient. This type of bradycardia is an appropriate response to the decreased metabolic rate that normally occurs with hypothermia.
Also the hypothermic ventricle is more prone to fibrillation with any sort of irritation. Thus the irritation of TCP could induce VF. Once the hypothermic ventricle begins to fibrillate, it is more resistant to defibrillation. Warm the patient and then treat any remaining arrhythmias.
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Q: What is TCP?
A: TCP means transcutaneous pacing.
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Q: What is chemical pacing?
A: Chemical pacing is when IV medications (epinephrine or dopamine) are used to increase the heart rate rather than the transcutaneous pacing which uses electricity to increase the heart rate.
goar0701 says
I’ve no taken ACLS for more than 12 years and I’m confused now, for ACLS protocol is Bradycardia considered less than 60/min or less than 50/min
Jeff with admin. says
For ACLS protocol, what is important is whether the patient is symptomatic.
Here is the quote directly from the AHA provider manual.
“Any rhythm disorder with a heart rate <60/min. When the bradycardia is the cause of symptoms, the rate is generally<50/min.” AHA Provider manual pg. 107
Kind regards,
Jeff
Emarie303 says
Is Atropine used for treatment of relative bradycardia?
Jeff with admin. says
Yes, atropine could be used to treat relative bradycardia. In these situations, you would want to ensure that significantly increasing the heart rate will not worsen the patient’s condition. For instance, in the case of MI, significantly increase the heart rate with atropine could worsen the ischemia to the heart.
You would treat relative bradycardia just as you would treat any bradycardia. Use the bradycardia algorithm and consider the H and T’s for bradycardia.
Kind regards,
Jeff
Manuel Mallol says
I read the NEJM publication about outcomes of some cohort using dopamine vs NA, showing an elevation of mortality rate using dopamine in cardiogenic and septic shock. Now, in many ICU and emergency units we don’t give dopamine to our patients with a synthomatic bradycardia with complete AV block. My question is about dopamine vs another vasoactive drug, if I don’t have transcutaneous pacemaker.
Thank you in advance,
Manuel.
Jeff with admin. says
I don’t know if there is an exact answer for dopamine vs. norepinephrine but my preference would be norepinephrine. The clinical trials seem to lean toward norepinephrine.
Here are a couple of articles regarding this issue:
Norepinephrine vs. Dopamine
Norepinephrine vs. Dopamine #2
Kind regards,
Jeff
NM Baillie says
In the past the good old standby drug used as a “Pacemaker” was Isuprel, a pure beta agonist ,which seems to have fallen into disfavor. Comments?
A suggestion inre ACLS Cardiac Arrest Algorithm.Why not raise the patient’s legs, or at least utilise the Trendelenberg position to provide added central volume by “auto-transfusion”. The degree of extra volume provided could easily be adjusted by what would be such simple and non-invasive manouvers . As many will have observed, when patients are “crashing” during even very cautious induction for CABG surgery, with low LVEF, raising adults’ legs can provide 1.0 to1.2 L auto- transfusion with laudable results.I used the latter example to illustrate the point,and am aware that it is not strictly analogous.Feedback please.
Chris with Admin. says
I have not used Isuprel a single time in 20 years of nursing and I have no experience with this drug to make a comment.
At this time, it is unclear whether trendelenburg position improves outcomes and there is some evidence that suggests that I could even be detrimental to outcomes when hemodynamic status is compromised. Here is one article on the subject: Trendelenburg position and hemodynamic status.
Kind regards,
Chris
Jeff with admin. says
Also here: Trendelenburg position and hemodynamic status.
rcain says
About 3 years ago at one of the hospitals I worked at in the Louisville, KY area, there was an educational initiative teaching the nursing staff to not do Trandelenburg position in any circumstances. Old habits die hard, but I think in the future we will see it done less and less.
Alison Miller says
Please clarify: in the above algorithm, for Dopamine it’s written as “Dosage is 2-10 micrograms/kg/min infusion.” For Epinephrine, it’s written as “Dosage is 2-10 micrograms/min.” Is Dopamine weight driven and epi is not? Or is this a typo?
Thanks!!
Jeff with admin. says
Within the bradycardia algorithm, the dopamine drip is weight based and the epinephrine drip is not. Epinephrine is 2-10 mcg/min and dopamine is 2-10 mcg/kg/min.
Kind regards,
Jeff
Jon says
Hey, I’ve got a scenario that I am hoping you could give me some feedback on. 58 y/o female with every text book S/S of ACS, Short of vomiting, syncope, or AMS. Pt has PMHx of AMI and also said her that in the past her BP has bottomed out during cardiac events. Over the past couple weeks, Pt has been popping Nitro like tictacs. She took x3 rounds of NTG with in the last hour or two before she called 911. The last round of NTG was 15 mins ago before.
Her BP is now 80/40. Her ecg revealed sinus Brady with a HR ranging btwn 50-60 BPM. ST elevation at 1mm to just barely 2 mm ST across inferior leads and reciprocal changes suggestive of a RCA occlusion. We gave ASA, started a NS fluid bolus, and 2 lpm of O2 to maintain SaO2 at 99%, and activated the cath lab (largely based off Pt presentation). Approx 15 min emergency transport to the hospital.
I was on the fence about giving Atropine, to boost cardiac output in hopes of helping out her BP, but ultimately elected not to. My reasoning was that the cause of hypotension was reduced preload due to an right-sided/ inferior AMI and NTG overload. I was worried that Atropine would caue increased Cardic O2 consumption and create an increased work load on the heart. I didn’t want to throw more drugs on the mess already created, and possibly cause more harm than good. I imagined a worse case scenario of creating a second or third degree heart block, since this type of AMI is notorious for causing Infarction damage to the AV node,
Was I out of line wth my thinking? And I was wondering where to draw the line between the Brady Cardic and ACS algorithms, or if they should be conducted simaltaneously? My thoughts at the time was that I would start TCP if her heart rate dropped into the 40’s, but it never dropped below 50 bpm. Thanks in advance for your feedback.
Jeff with admin. says
I think that you made the right choice to hold the Atropine. You are correct in that atropine could have pushed the workload up and worsened an infarction. The BP was borderline and I would have been satisfied with this BP at 80/40. You made the right decision to use TCP if the HR dropped below 40. I think that your decisions were well thought out and correct given the situation. You can use both the ACS algorithm and Bradycardia algorithm at the same time. Just make your decisions with saving as much of the myocardium as possible.
Kind regards,
Jeff
khawla says
Could atropine be given as IV infusion in bradycardia?? and if possible what is the conc and max rate of infusion
Jeff with admin. says
The half-life of atropine is 2 hours. Therefore, it would not be necessary to give it as an infusion. Something with a half-life of this length should be given as needed by IV bolus. There would be better medication to use in this type of situation. You would use dopamine or epinephrine. These 2 medications have been found to be very effective in the treatment of symptomatic bradycardia.
Kind regards,
Jeff
Jeff with admin. says
Atropine as a potent anticholinergic agent has been employed as a continuous infusion in the treatment of tetanus and organophosphate poisoning. Kind regards, Jeff
James says
What if the bradycardia is junctional at 40 and the patient is symptomatic? Still atropine, pacing, and epi?
Jeff with admin. says
Yes, that would be correct. In that order. Epinephrine or dopamine could be used for chemical pacing if needed.
Kind regards,
Jeff
Rene says
With second line treatment if atropine is ineffective, would that mean that after the 6th dose or 3 mg of atropine?
Jeff with admin. says
Not necessarily. The patients clinical condition would determine this. If you have given 2 doses of atropine and have not seen any changes in the patients clinical condition, you would prepare for the use of chemical or electrical pacing. If the patient’s clinical condition is worsening, DO NOT delay pacing for continued use of atropine.
Kind regards,
Jeff
Kelvan_18 says
Would you pace a patient with complete heart block with HR 20’s bp 120/70. What if he is completely symptoms free?
Jeff with admin. says
Not necessary, but I would have the patient monitored and attached to TCP in the case that it was needed. I doubt that you will see many patients who have a heart rate of 20 without symptoms. Kind regards, Jeff
Carrie says
According to the AHA, can a nurse certified in ACLS pace symptomatic bradycardia without a physician order? I thought I remember reading about this topic in the book but now can’t find it. I’m a new instructor and have had questions from learners. Thank you.
Jeff with admin. says
If you did not have a direct physician order, you would need some type of standing order that your hospital or facility already had in place.
A nurse would not be able to implement pacing without some type of physician order whether it is a standing order, direct verbal order or written order.
Kind regards,
Jeff
hjc says
Setting a couple Milli-Amp above the capture point rooted from the 1960s when impedance and development of insulation at the contact of the pace site that occasional lost of capture occurred.
Emi says
I have 61 y-male patient with STEMI and TAVB. BP 110/50 mmHg, HR 24 bpm, RR 12x/min. The patient is compos mentis. There is no TPM in my hospital. The therapy are atropin 3×0,5 mg, heparin infusion 10 ui/kg/hr, aspilet 1×80 mg, CPG 1×75 mg. is it sufficient? Do the patient need chemical pacing?
Jeff with admin. says
I’m sorry to hear about this situation, and I do apologize that I cannot answer your question. This site is for educational purposes only and law prohibits me from giving any type of real medical advice for an actual patient. Any time that you want to email about any kind of educational scenario, I could answer this type of question. If you send any questions please word them like this. “If I had a patient with…” or “If I was dealing with….” Or “suppose I had a scenario like this… “
Kind regards,
Jeff
lavinia says
I hv a 75 yo pt who presented with history of syncope and stopped breathing at home.also with chestpain.he is known hhypertensive on a milo ride and aspirin.ecg show increased PQ interval .I hv no access to 12 lead ecg though.advise.
Jeff with admin. says
I cannot give medical advice, but I can say that in this situation, I would want to control the patient’s pain. If the patient was a candidate, I would also consider fibrinolytic therapy. If you don’t have access to basic equipment like an ECG, you should consider developing protocols and algorithms for treating patients in your setting with the things that you have available.
Kind regards,
Jeff
Nicola says
Hello Jeff,
Would you treat a 76 yo m patient with the bradycardia algorithm who initially complained of chest pain and a syncopal episode. Now presenting with mild difficulty breathing, alert and oriented x4, a Bp 112/68, feeling of impending doom ECG showing second degree type 1 av block at a rate of 60?
Since 60bpm is not Brady and he is normotensive….inspite of impending doom (not unstable, but symptomatic)……?
O2, IV, monitor, 12 lead. Reassure, Keep pacer pads on in case he deteriorates or become symptomatic. I get a little hung when the ranges are right there…. What are your thoughts?
Jeff with admin. says
I would first treat the patient with the Acute Coronary Syndrome Algorithm. This scenario sounds like a possible MI. I would not treat with the bradycardia algorithm at this time.
The patient should be admitted to a telemetry unit. Provide O2 if needed. Q 8 hour troponin levels and 12 Lead ECG. Monitor for increased pain, syncope, or other symptoms. Observe for 24 hours and perform a stress test if the patient has any further symptoms.
If the patient develops bradycardia treat per the bradycardia algorithm. You would not need to leave the patient attached to a pacemaker if the heart rate is normal and the patient is stable. Those are my thoughts.
Kind regards,
Jeff
janicepettway60 says
This is a silly question but what is chemical pacing? And ifa patient in bradycardia why give IV fluid?
Jeff with admin. says
Chemical pacing is when IV medications (epinephrine or dopamine) are used to increase the heart rate rather than the pacemaker which uses electricity to increase the heart rate.
Kind regards,
Jeff
radiatelight says
I thought the maximum dose of atropine was 6mg, not 3mg as stated?
Jeff with admin. says
No. The maximum total dose for atropine in a 24 hour period is 3mg. Here is the AHA reference.
In the bottom right hand corner of the PDF, you will see the max dosing details.
Kind regards,
Jeff
Abilio says
In Europe/Portugal is also 3mg de maximum dose for atropine