Late onset atrioventricular nodal tachycardia.

AV nodal tachycardia may present at any age, but onset in late adulthood is considered uncommon. To evaluate whether onset of AV nodal tachycardias at older age is related to organic heart disease (possibly setting the stage for re-entry due to degenerative structural changes) 32 consecutive patients with symptomatic AV nodal tachycardia were studied. The age at onset of attacks showed a bimodal pattern, with 2 peaks: one between 15 and 35 years (22 patients) and one around 55 years (10 patients). Significantly more older patients had an underlying heart disease (60% versus 14%, P < 0.01), with coronary artery disease in 4 and hypertensive heart disease in 3. Frequent supraventricular ectopic activity was seen during baseline 24-h ambulatory monitoring in all the older patients, versus in only half of the younger patients (P = 0.005). These results indicate that late onset AV nodal tachycardia (i.e. > age 45 years) is not infrequent (33%). The frequent supraventricular arrhythmias on one hand and age-related structural AV nodal changes, potentially enhanced by underlying heart disease on the other, both may contribute to the development of late onset re-entrant AV nodal tachycardia.