Exact data reflecting the epidemiology of paroxysmal AV block is unavailable. However certain studies have shown an increased incidence in the elderly, no gender predisposition and an association with bundle branch blocks.

• Given the difficulty in diagnosis, sporadic presentation and sparse literature available, the exact incidence and prevalence of paroxysmal AV block is unknown.

• An unpublished study done at Beth Israel Deaconess Medical Centre in collaboration with a cardiology department in the Netherlands found that paroxysmal AV block was most associated with RBBBs followed by LBBBs, intraventricular conduction delays and normal QRS complexes.
  • An age presentation of 26-99 years of age, an equal incidence in both men and women and an increased prevalence in older individuals were also seen.
  • However, the association between paroxysmal AV block and RBBB is a matter of much debate, as it is not sure whether RBBB causes a direct effect or is a sign seen in an aging population.^[1]

• The ISSUE 2 study was characterised by a population of individuals with a high mean age, a history of recurrent syncope beginning in middle or older ages, and frequent injuries probably due to presentation without warning.^[2]