Use of Adenosine Test for the Exclusion of Preexcitation Syndrome in Asymptomatic Individuals

BACKGROUND: Resting electrocardiogram is a routine procedure for the identification of potentially fatal conditions, including preexcitation syndrome (PES). Intravenous adenosine is a sensitive and specific means of exposing inapparent pathways in such patients. Yet, it may not be sensitive when complete atrioventricular (AV) block is not achieved because a low dose of adenosine is used. We evaluated the yield of a high-dose adenosine test that achieved complete AV nodal block for unmasking inapparent pathway in a healthy population. METHODS: We retrospectively reviewed all Israeli air force (IAF) academy candidates who were referred to adenosine test based on a cardiologist's suspicion of PES. The results of the adenosine test were recorded, including the adenosine dose required to achieve complete AV block. The medical records of the subjects were reviewed to identify any adverse cardiovascular outcome. RESULTS: Fifty-nine subjects who underwent adenosine test were followed for 35.42 ± 24 months. Complete AV block was achieved in all subjects with an average adenosine dose of 22.51 ± 12.67 mg. None of the subjects had evidence of an inapparent pathway. All subjects completed military service without adverse outcomes. CONCLUSIONS: The vast majority of young patients with a short PR interval do not have evidence of an accessory pathway and have a favorable prognosis. Thus, the yield of adenosine test in young combat recruits is questionable. Yet, if there is no evidence of an accessory pathway while achieving complete AV block on adenosine test, the chance of an accessory pathway being present is probably extremely low.