What are the indications for referral to a cardiologist in patients diagnosed with heart block?

Indications for referral to a cardiologist in patients diagnosed with heart block include:

• Presence of second degree or third degree atrioventricular (AV) block on a 12-lead electrocardiogram (ECG) requires urgent referral to cardiology ¹.
• High degree AV block detected on ECG in the context of palpitations or transient loss of consciousness (TLoC) warrants urgent cardiology assessment ¹,².
• Patients with heart block who have symptoms such as syncope or near syncope, chest pain, or lightheadedness should be referred routinely or urgently depending on severity ¹,².
• Family history of sudden cardiac death under the age of 40 years in a patient with heart block is an indication for urgent cardiology referral ¹,².
• Evidence or suspicion of structural heart disease, heart failure, or hypertension in a patient with heart block should prompt routine referral to cardiology ¹,².
• Any ECG abnormalities accompanying heart block, such as bundle branch block or other conduction abnormalities, support referral ¹,².
• In the context of transient loss of consciousness, any conduction abnormality including any degree of heart block on ECG is a red flag requiring urgent cardiovascular assessment ².

Referral urgency depends on clinical judgement but second or third degree AV block generally mandates urgent cardiology evaluation to assess for potential pacing or other interventions ¹,².