Safety and efficacy of high-dose adenosine-induced asystole during endovascular AAA repair

Purpose: To assess the safety and efficacy of high-dose adenosine administr ation to increase the precision of endovascular abdominal aortic aneurysm ( AAA) repair using a balloon deployed stent-graft. Methods: From January 1997 to March 1999, 98 AAA patients (79 men; mean age 71 years, range 62-91) were treated with balloon-expandable stent-grafts u nder an approved protocol. After placing a temporary transvenous ventricula r lead or an external transthoracic pacing electrode, adenosine (24 mg init ially) was administered in an escalating dose fashion to induce at least 10 seconds of asystole, during which the proximal stent was expanded. Results: Adenosine dosages ranged from 24 to 90 mg (median 24 mg). Nine (9. 2%) self-limiting cardiac events were observed: 2 (2.0%) episodes of transi ent myocardial ischemia, 2 (2.0%) cases of atrial fibrillation requiring ca rdioversion, 1 (1.0%) transient left bundle branch block lasting <10 second s, and 4 (4.1%) prolonged periods of asystole requiring temporary pacemaker activation. There were no cases of bronchospasm or worsening obstructive p ulmonary disease, and no patients required inotropic support after adenosin e-induced asystole. Conclusions: Cardiac events following adenosine-induced asystole are infreq uent, mild, and easily treated. The perioperative use of high-dose adenosin e to ensure precise stent-graft placement appears to be a safe method of in ducing temporary asystole during endovascular aortic repair.