ADENOSINE-INDUCED TRANSIENT CARDIAC STANDSTILL IN CATHETER INTERVENTIONAL PROCEDURES FOR CONGENITAL HEART-DISEASE

Objective-To describe the use of intravenous adenosine to create trans ient cardiac standstill during balloon dilatation procedures for conge nital heart defects. Setting-A tertiary paediatric cardiac centre. Des ign and patients-This was a prospective pilot study. Thirteen patients born with congenital heart disease and who had stenotic lesions requi ring relief were considered for the technique. All were suitable for b alloon dilatation. Their ages ranged from 2 months to 30 years, mean ( SD) 9.9 (9.8) years. The dose of adenosine varied from 0.125 mg/kg to 0.555 mg/kg, mean 0.33 (0.127). Results-Two patients only developed si nus bradycardia in response to adenosine, which may have been related to the technique of administration. The other 11 experienced a period of asystole, which ranged from 2.4 to 10.8 seconds, mean 4.99 (2.27), and a total atrioventricular black period of 5.0 to 21.2 seconds, mean 9.47 (4.64). The interval between adenosine injection and the onset o f asystole varied from 2.4 to 15.8 seconds, mean 8.05 (3.6), depending ran cannula size, sits of administration, and cardiac output. The pea k gradient across the stenotic: lesions fell from 52.3 (23.7) to 17.8 (11.9) mm Hg (p < 0.001). Apart from one short episode of atrial fibri llation there were no complications. Conclusions-Intravenous adenosine is a safe and effective agent for creating transient cardiac standsti ll during balloon dilatation procedures for congenital heart disease. This achieves stability which is likely tea improve results and reduce complications. It may have: applications in other fields of cardiac i ntervention where an immobile heart Is desirable during the critical p hase of a procedure.