From the Guidelines
The primary treatment for complete heart block is permanent pacemaker implantation, as recommended by the 2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1. This involves surgically placing a small electronic device under the skin, typically near the collarbone, with leads extending to the heart to regulate its electrical activity. For temporary management before pacemaker placement, medications like atropine (0.5-1mg IV) or isoproterenol (2-10 mcg/min IV infusion) may be used to increase heart rate, or a temporary transcutaneous or transvenous pacemaker might be placed. The specific type of pacemaker depends on the patient's condition - single-chamber pacemakers are simpler but dual-chamber pacemakers better mimic natural cardiac conduction. Some key points to consider in the management of complete heart block include:
- The decision to implant a pacemaker in a patient with abnormal AV conduction depends on the presence of symptoms related to bradycardia or ventricular arrhythmias and their prognostic implications 1.
- Pacemaker implantation is a Class I indication in the symptomatic individual with congenital complete AV block or the infant with a resting heart rate less than 55 bpm, or less than 70 bpm when associated with structural heart disease 1.
- Advanced second- or third-degree AV block that persists for at least 7 days and that is not expected to resolve after cardiac surgery is considered a Class I indication for pacemaker implantation 1. After implantation, patients need regular follow-up appointments (typically every 3-12 months) to check battery life and device function. Pacemaker implantation is necessary because complete heart block represents a failure of electrical impulses to travel from the atria to the ventricles, causing the ventricles to beat at their own slow intrinsic rate (typically 20-40 beats per minute), which is insufficient to maintain adequate cardiac output and can lead to symptoms like fatigue, syncope, or even sudden cardiac death. It is also important to consider the risk of late-onset complete AV block years or decades after surgery for congenital heart disease in patients with transient postoperative AV block, and the potential need for lifelong cardiac pacing 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.
- Treatment for complete heart block: Atropine may be used to treat complete heart block, as it can accelerate the idioventricular rate in some patients or stabilize the rate in others 2.
- Key effects: The drug can counteract vagal cardiac slowing or asystole and may improve heart rate in patients with complete heart block.
From the Research
Treatment for Complete Heart Block
The treatment for complete heart block typically involves the implantation of a permanent pacemaker (PPM) 3. This is considered the standard of care for patients with complete heart block and second-degree type II atrioventricular (AV) block, regardless of symptoms, when the conduction abnormality is irreversible.
Management of Complete Heart Block
Effective management of complete heart block includes:
- Accurate interpretation of a 12-lead EKG
- Assessment of hemodynamic stability and systemic perfusion
- Time-sensitive pharmacologic or procedural intervention, such as:
- Administering IV atropine
- Attempting transcutaneous pacing
- Placing a transvenous pacemaker
- Emergent consultation with interventional cardiology 4
Pacemaker Implantation
Pacemaker implantation is often necessary for patients with complete heart block, particularly those with recurrent or permanent block 5. The implantable cardiac pacemaker has been shown to be an effective and reliable method for long-term pacing of the heart 6.
Considerations for Young or Middle-Aged Adults
In young or middle-aged adults, the etiology of complete atrioventricular block may be different from that in older adults, and may include conditions such as coronary artery disease, autoimmune disorders, or congenital cardiopathies 7. A diagnostic algorithm may be helpful in determining the underlying cause of complete heart block in this age group.