ACC/AHA/HRS 2018 Guideline on Bradycardia and Cardiac Conduc


ACC/AHA/HRS 2018 Guideline on Bradycardia and Cardiac Conduction Delay

The American College of Cardiology, American Heart Association, and the Heart Rhythm Society have recently released a guideline for the management of patients with bradycardia, or symptoms thought to be associated with bradycardia or cardiac conduction system disorders. The guidance document has been copublished in the journal Circulation and HeartRhythm. 

This guideline supersedes the pacemaker recommendations made in the “ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities” and “2012 ACCF/AHA/HRS Focused Update Incorporated Into the ACCG/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities. 

Evaluation of Bradycardia and Conduction Disease Algorithm 

Management of conduction disorders algorithm

Top 10 Take-Home Messages

1. Sinus node dysfunction is most often related to age-dependent progressive fibrosis of the sinus nodal tissue and surrounding atrial myocardium leading to abnormalities of sinus node and atrial impulse formation and propagation and will therefore result in various bradycardic or pause-related syndromes. 

2. Both sleep disorders of breathing and nocturnal bradycardias are relatively common, and treatment of sleep apnea not only reduces the frequency of these arrhythmias but also may offer cardiovascular benefits. The presence of nocturnal bradycardias should prompt consideration for screening for sleep apnea, beginning with solicitation of suspicious symptoms. However, nocturnal bradycardia is not in itself an indication for permanent pacing. 

3. The presence of left bundle branch block on electrocardiogram markedly increases the likelihood of underlying structural heart disease and of diagnosing left ventricular systolic dysfunction. Echocardiography is usually the most appropriate initial screening test for structural heart disease, including left ventricular systolic dysfunction. 

4. In sinus node dysfunction, there is no established minimum heart rate or pause duration where permanent pacing is recommended. Establishing temporal correlation between symptoms and bradycardia is important when determining whether permanent pacing is needed. 

5. In patients with acquired second-degree Mobitz type II atrioventricular block, high-grade atrioventricular block, or third-degree atrioventricular block not caused by reversible or physiologic causes, permanent pacing is recommended regardless of symptoms. For all other types of atrioventricular block, in the absence of conditions associated with progressive atrioventricular conduction abnormalities, permanent pacing should generally be considered only in the presence of symptoms that correlate with atrioventricular block. 

6. In patients with a left ventricular ejection fraction between 36% to 50% and atrioventricular block, who have an indication for permanent pacing and are expected to require ventricular pacing >40% of the time, techniques that provide more physiologic ventricular activation (e.g., cardiac resynchronization therapy, His bundle pacing) are preferred to right ventricular pacing to prevent heart failure. 

7. Because conduction system abnormalities are common after transcatheter aortic valve replacement, recommendations on postprocedure surveillance and pacemaker implantation are made in this guideline. 

8. In patients with bradycardia who have indications for pacemaker implantation, shared decision-making and patient-centered care are endorsed and emphasized in this guideline. Treatment decisions are based on the best available evidence and on the patient’s goals of care and preferences. 

9. Using the principles of shared decision-making and informed consent/refusal, patients with decision-making capacity or his/her legally defined surrogate has the right to refuse or request withdrawal of pacemaker therapy, even if the patient is pacemaker dependent, which should be considered palliative, end-of-life care, and not physician-assisted suicide. However, any decision is complex, should involve all stakeholders, and will always be patient specific. 

10. Identifying patient populations that will benefit the most from emerging pacing technologies (e.g., His bundle pacing, transcatheter leadless pacing systems) will require further investigation as these modalities are incorporated into clinical practice.




The American College of Cardiology is a 52,000-member medical society that is the professional home for the entire cardiovascular care team. The mission of the College is to transform cardiovascular care and to improve heart health. The American Heart Association is a non-profit organization in the United States that fosters appropriate cardiac care in an effort to reduce disability and deaths caused by cardiovascular disease and stroke. The Heart Rhythm Society (HRS) is an international non-profit organization that promotes education and advocacy for cardiac arrhythmia professionals and patients.

Note: This list is a brief compilation of some of the key recommendations included in the Guideline and is not exhaustive and does not constitute medical advice. Kindly refer to the original publication here:

About Author
Dr. Prachi Chhimwal
Dr. Prachi Chhimwal is an Editor at PlexusMD and is a part of the Engagment Team. She curates the Technical Content posted daily on the news feed. She graduated from Army College of Dental Sciences (B.D.S) and went on to pursue her post-graduation (M.D.S) in Oral & Maxillofacial Pathology. After a decade in the field of dentistry she took a leap of faith and joined PlexusMD. A badminton enthusiast, when not working you can find her reading, Netflixing or enjoying stand-up comedy shows.
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