A review on advanced atrioventricular block in young or middle-aged adults.

Complete atrioventricular block is a relatively uncommon arrhythmia that is nonetheless increasingly seen in elderly people of developed countries, due to the increase in life expectancy. Congenital and degenerative etiologies are the most commonly seen among young and old patients, respectively. However, scientific literature is surprisingly scarce regarding the etiology of complete atrioventricular block in the asymptomatic otherwise healthy young and middle-aged adult population. Coronary artery disease, autoimmune disorders such as systemic lupus erythematosus or rheumatoid arthritis, history of acute or chronic infectious or hypersensitivity myocarditis, infiltrative processes, hypothyroidism, congenital cardiopathies such as left ventricular noncompaction or Ebstein anomaly, lamin A/C mutations, and pathologic hypervagotony and idiopathic degenerative scleroatrophy of the atrioventricular junctional specialized tissue (Lenegre-Lev disease) are among the most frequent etiologies of complete atrioventricular block in young or middle-aged adults. To our knowledge, no comprehensive review on the specificities of the investigation warranted in this age group has ever been developed, nor have the implications of particular diagnoses on treatment modalities been appropriately addressed. We aim at reviewing the most frequent differential diagnoses of advanced atrioventricular block in otherwise healthy asymptomatic or mildly symptomatic young or middle-aged adults and their impact on therapeutic options. Additionally, we suggest a diagnostic algorithm that may be helpful in this group of patients.