From the Guidelines
Complete heart block (CHB) is a serious cardiac condition that requires immediate medical attention, and the standard of care for most patients with CHB is permanent pacemaker implantation. This condition occurs when the electrical signals from the atria (upper heart chambers) cannot reach the ventricles (lower chambers), preventing coordinated contraction between the atria and ventricles and potentially causing symptoms like fatigue, dizziness, fainting, or even cardiac arrest if left untreated 1.
Causes and Symptoms of CHB
The causes of CHB can be attributed to various factors, including aging, heart disease, or medication effects, which can damage the AV node or His-Purkinje system 1. Symptoms of CHB may include fatigue, dizziness, fainting, or even cardiac arrest if left untreated.
Treatment Options for CHB
While waiting for pacemaker implantation, temporary measures may include atropine (0.5-1mg IV), isoproterenol (2-10 mcg/min IV), or temporary transcutaneous or transvenous pacing for unstable patients 1. Patients with CHB should avoid medications that slow heart rate, such as beta-blockers, calcium channel blockers, and certain antiarrhythmics.
Importance of Regular Follow-up
Regular follow-up with a cardiologist is essential for pacemaker checks and battery replacement (typically every 7-10 years) 1. This ensures that the pacemaker is functioning properly and reduces the risk of complications.
Key Considerations for CHB Management
It is crucial to note that the provided evidence on hepatitis B (CHB) is not directly related to the cardiac condition Complete Heart Block (CHB) 1. Therefore, the management of Complete Heart Block (CHB) should be based on the standard of care for cardiac conditions, rather than hepatitis B guidelines. The primary goal of CHB treatment in the context of cardiac care is to restore proper heart rhythm and prevent complications, rather than suppressing HBV replication.
From the Research
Definition and Causes of CHB
- Congenital complete heart block (CCHB) is defined as atrioventricular conduction abnormalities diagnosed in utero or within the first 27 days of life 2.
- Maternal autoimmune disease and congenital heart defects are the most common causes of CCHB 2, 3.
- The presence of anti-Ro/SSA and/or anti-La/SSB antibodies in the mother increases the risk of CCHB in the fetus 3, 4.
Diagnosis and Treatment of CHB
- Fetal echocardiography can confirm the diagnosis of CCHB before birth, while electrocardiography can confirm the diagnosis after birth 3, 5.
- Cardiac pacemakers are implanted in symptomatic patients with CCHB, and may also be recommended for asymptomatic patients to prevent catastrophic events 2, 3, 6.
- Hydroxychloroquine may have a role in preventing autoimmune CCHB, but further research is needed to confirm its efficacy and safety 2, 5.
Complications and Management of CHB
- Patients with CCHB may develop symptomatic bradycardia and cardiomyopathy, which can be managed with pacemaker implantation and other treatments 2, 3.
- The use of conventional right ventricular apical pacing may produce left ventricular dysfunction, and alternative pacing sites or biventricular pacing may be necessary 3.
- Advances in prenatal diagnosis and management of CCHB have improved outcomes, but further research is needed to develop effective prenatal interventions 5.