Efficacy and safety of adenosine in diagnosis and treatment of regular tachycardia in the elderly

Background Adenosine is currently used in the treatment and differential di agnosis of regular tachycardia. However, the efficacy of its employment has not been studied in elderly people, Methods We evaluated the safety, and the diagnostic and therapeutic utility of adenosine in elderly people aged over 70 years with regular sustained t achycardia, compared with a group of patients aged under 70 years affected by the same arrhythmia. Adenosine was given to 107 patients in increasing b olus doses up to 18 mg during regular broad and narrow complex tachycardia; 49 patients were aged 70 and over, and 58 patients were aged less than 70 years. In the former group, surface ECG showed 38 narrow complex tachycardi as and 11 broad complex ones; in the second group there were 48 narrow comp lex tachycardias and 10 broad complex ones. Results Adenosine was effective in 94% of the elderly patients and in 93% o f the younger patients, in the group aged over 70 years, adenosine restored sinus rhythm in 37% of patients and revealed the mechanism of arrhythmia i n 57%. Adenosine restored sinus rhythm in 50% of patients under 70 years an d revealed atrial or sinus tachycardia in 43%. The incidence of symptomatic side effects and peri-conversion ventricular arrhythmias was similar in th e two groups, There were ventricular pauses over 3 s long in four (8%) of t he older patients (maximum pause 7 s) and in two patients (3%) of the group under 70 years (maximum pause 6 a). No adverse haemodynamic effects were o bserved. Conclusion These data demonstrate the safety and the value of adenosine in the diagnosis and treatment of regular tachycardia in elderly patients. Cor onary Artery Dis 9:591-596 (C) 1998 Lippincott Williams & Wilkins.