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Kusumoto et al 2018 Bradycardia Clinical Practice Guidelines Circulation. 2019;140:e382–e482. DOI: 10.1161/CIR.0000000000000628 August 20, 2019 e425 CLINICAL STATEMENTS AND GUIDELINES III: Harm C-LD 2. In patients who had acute atrioventricular block attributable to a known reversible and nonrecurrent cause, and have had complete resolution of the atrioventricular block with treatment of the underlying cause, permanent pacing should not be performed.S6.4.2-1,S6.4.2-4–S6.4.2-9 III: Harm C-LD 3. In patients with asymptomatic vagally mediated atrioventricular block, permanent pacing should not be performed.S6.4.2-6–S6.4.2-10 Synopsis Atrioventricular block can be secondary to a potentially reversible primary process, such as metabolic derangements and some infectious diseases. For example, Lyme carditis causing atrioventricular block often resolves with antibiotics without the need for permanent pacing. Atrioventricular block attributable to medications, such as beta-blocker overdose or digoxin toxicity often resolve with supportive care and reversal or withdrawal of the offending drug although patients remain at risk for future bradycardia. In patients with obstructive sleep apnea, episodes of bradycardia during apneic episodes usually resolve with continuous positive airway pressure. Vagotonic atrioventricular block can result in paroxysmal atrioventricular block, and if asymptomatic, does not require pacing therapy. Atrioventricular block in the setting of ischemia and MI is addressed in Section 8.3. Recommendation-Specific Supportive Text 1. In patients with atrioventricular block and an acute infection such as Lyme disease, effective antibiotic treatment usually reverses the atrioventricular block although resolution may take a month or longer.S6.4.2-1 In general, permanent pacing is not warranted. However, for patients in whom atrioventricular block does not resolve, permanent pacing will be needed to alleviate the symptoms and bradycardia.S6.4.2-3,S6.4.2-11 2. There are several reversible causes of atrioventricular block unrelated to myocardial ischemia, including electrolyte derangements, notably hyperkalemia, and certain infections such as Lyme disease where treatment for the underlying cause also resolves the atrioventricular block.S6.4.2-3,S6.4.2-11,S6.4.2-12 Lyme disease affects the myocardium in approximately 5% of affected patients and the most common cardiac finding is atrioventricular block. However, atrioventricular block resolves after typically 1 to 2 weeks of antibiotic treatment.S6.4.2-1 Similarly, atrioventricular block has been reported in patients with rheumatic heart disease that resolved with antibiotics.S6.4.2-4 Acute overdose or toxicity of certain medications can also cause transient or reversible atrioventricular block. Conversely, new onset atrioventricular block in patients who have been on chronic stable doses of atrioventricular nodal blocking medications often does not resolve or can recur requiring permanent pacing.S6.4.2-13 Therefore, continued surveillance for recurrence of atrioventricular block is useful or even consideration for permanent pacing after the offending medication has been discontinued. Although PPM implantation is a relatively low-risk cardiac procedure, procedural complications and death directly related to implant can occur, and implanted leads have long-term management implications.S6.4.2-6–S6.4.2-9 3. Vagally mediated atrioventricular block observed with ambulatory electrocardiographic monitoring may be an incidental finding that occurred while the patient was sleeping or in other cases be associated with syncope. Vagally mediated atrioventricular block is felt to be attributable to neural reflexes, which result in simultaneous bradycardia and hypotension.S6.4.2-14 There is typically sinus rate slowing in conjunction with the onset of atrioventricular block and the atrioventricular block can be high grade or complete.S6.4.2-10 Atrioventricular block attributable to high vagal tone, such as during sleep, is almost always asymptomatic.S6.4.2-15 The level of the block is at the atrioventricular node, and there is normal atrioventricular nodal function when tested at EPS.S6.4.2-16 If asymptomatic, medical treatment or pacemaker implantation is not warranted for atrioventricular block attributable to high vagal tone or vagally mediated atrioventricular block. If the patient is having frequent syncopal episodes, treatment may be warranted if bradycardia appears to be the dominant factor in these episodes.S6.4.2-17 Although PPM implantation is a relatively low-risk cardiac procedure, procedural complications and death directly related to implant can occur, and implanted leads have long-term management implications.S6.4.2-6–S6.4.2-9 Recommendations for Potentially Reversible or Transient Causes of Atrioventricular Block (Continued) COR LOE Recommendations Downloaded from http://ahajournals.org by on October 7, 2026