From the Guidelines
Complete heart block management requires prompt recognition and intervention, with permanent pacemaker implantation being the definitive treatment for symptomatic patients, as recommended by the 2018 ACC/AHA/HRS guideline 1.
Key Considerations
- Patients with symptomatic complete heart block should receive immediate temporary pacing followed by permanent pacemaker implantation.
- For emergency management, atropine 0.5-1mg IV can be administered while awaiting temporary pacing, though its effectiveness is limited in high-grade AV blocks.
- Dopamine (2-10 mcg/kg/min) or epinephrine (2-10 mcg/min) infusions may be used in hemodynamically unstable patients to increase heart rate temporarily.
- Transcutaneous pacing should be initiated promptly in symptomatic patients until transvenous temporary pacing can be established.
Permanent Pacemaker Implantation
- The urgency of permanent pacemaker placement depends on the underlying cause, symptoms, and hemodynamic stability.
- Asymptomatic patients with chronic complete heart block may be monitored closely while arranging for elective pacemaker implantation.
- Management should include identifying and treating reversible causes such as medication effects (beta-blockers, calcium channel blockers), electrolyte abnormalities, or acute ischemia.
- According to the 2018 ACC/AHA/HRS guideline, permanent pacing is recommended for patients with acquired second-degree Mobitz type II atrioventricular block, high-grade atrioventricular block, or third-degree atrioventricular block not attributable to reversible or physiologic causes, regardless of symptoms 1.
- The 2012 ACCF/AHA/HRS focused update also recommends permanent pacemaker implantation for third-degree and advanced second-degree AV block at any anatomic level associated with bradycardia with symptoms or ventricular arrhythmias presumed to be due to AV block 1.
Special Considerations
- Patients with neuromuscular diseases associated with conduction disorders, such as muscular dystrophy or Kearns-Sayre syndrome, may require permanent pacing with additional defibrillator capability if needed and meaningful survival of greater than 1 year is expected 1.
- In patients with infiltrative cardiomyopathy, such as cardiac sarcoidosis or amyloidosis, and second-degree Mobitz type II atrioventricular block, high-grade atrioventricular block, or third-degree atrioventricular block, permanent pacing with additional defibrillator capability if needed and meaningful survival of greater than 1 year is expected, may be considered 1.
From the FDA Drug Label
Atropine also may lessen the degree of partial heart block when vagal activity is an etiologic factor In some patients with complete heart block, the idioventricular rate may be accelerated by atropine; in others, the rate is stabilized.
Atropine may be used in the management of complete heart block as it can accelerate the idioventricular rate in some patients or stabilize the rate in others. However, its effect may vary among patients. 2
From the Research
Complete Heart Block Management
- Complete heart block (CHB) is a medical emergency that can be fatal if not urgently treated 3
- Permanent pacemaker (PPM) implantation is the standard of care in patients with CHB and second-degree type II atrioventricular (AV) block, irrespective of patient symptoms, when the conduction abnormality is irreversible 3
- The management of CHB involves assessing the patient's risk of syncope and determining the need for pacing 4
- Patients with Adams-Stokes attacks require pacing, while asymptomatic patients with complete heart block and those with minor symptoms may be assessed using studies of both ventricular pacemaker function and site to determine the need for a pacemaker 4
Pacemaker Implantation
- PPM implantation is associated with mortality in patients with acute coronary syndrome 5
- Advanced age, heart failure, arrhythmias, and left ventricular branch block at intensive care unit admission are associated factors with PPM implantation in acute coronary syndrome patients 5
- The survival rate after PPM implantation for atrioventricular block is 88% at 1 year, 61% at 5 years, and 49% at 10 years 6
- Early versus delayed pacemaker implantation for heart block after valve surgery is a cost-effectiveness issue, with watchful waiting being a cost-effective management strategy compared to early placement 7
Patient-Centered Care
- Patient-centered care and shared decision-making are important in the management of CHB, particularly when there is an incongruence between the principles of beneficence and patient autonomy 3
- Patients with CHB may decline PPM implantation, and their decision should be respected and supported by healthcare providers 3