To define possible factors affecting the single bolus success rate of adenosine, we analyzed 84 patients with electrophysiologic study-proven stable atrioventricular (AV) nodal reentrant tachycardia. Each patient was treated according to the guidelines of American Heart Association/Advanced Cardiac Life Support until termination of the tachydysrhythmia. The patients were subdivided into group A (n=30), successful cardioversion following a single 6mg dose of adenosine and group B (n=54), failure to convert after a single dose. The two groups were comparable in age, sex and underlying diseases. In group B, the tachycardia rate was faster both pre (176±18 bpm vs. 166±14 bpm, P<0.01) and immediately post cardioversion (100±14 bpm vs. 89±8 bpm, p<0.0l). The patients in group A were more likely to report the concomitant use of beta-adrenergic antagonists (20% vs. 2%) and sedatives (15% vs. 2%) (p<0.001). In those subjects already taking beta-adrenergic antagonists (n=8) and sedatives (n=7), the single-shot success rates were significantly higher than those without (88% vs. 34%, p<0.0l; and 83% vs. 36%, p<0.0l). Injection sites also appeared very important. Those administered adenosine via a central vein had 100% single bolus success, with only 38% success via the antecubital veins and 13% for the dorsum of the hand, (p<0.00l) In summary, the success of adenosine bolus cardioversion of AV nodal reentrant tachycardia appears to depend upon distance from the injection site to the heart and the presence of medications that may attenuate the patient’s sympathetic tone.
To define possible factors affecting the single bolus success rate of adenosine, we analyzed 84 patients with electrophysiologic study-proven stable atrioventricular (AV) nodal reentrant tachycardia. Each patient was treated according to the guidelines of American Heart Association/Advanced Cardiac Life Support until termination of the tachydysrhythmia. The patients were subdivided into group A (n=30), successful cardioversion following a single 6mg dose of adenosine and group B (n=54), failure to convert after a single dose. The two groups were comparable in age, sex and underlying diseases. In group B, the tachycardia rate was faster both pre (176±18 bpm vs. 166±14 bpm, P<0.01) and immediately post cardioversion (100±14 bpm vs. 89±8 bpm, p<0.0l). The patients in group A were more likely to report the concomitant use of beta-adrenergic antagonists (20% vs. 2%) and sedatives (15% vs. 2%) (p<0.001). In those subjects already taking beta-adrenergic antagonists (n=8) and sedatives (n=7), the single-shot success rates were significantly higher than those without (88% vs. 34%, p<0.0l; and 83% vs. 36%, p<0.0l). Injection sites also appeared very important. Those administered adenosine via a central vein had 100% single bolus success, with only 38% success via the antecubital veins and 13% for the dorsum of the hand, (p<0.00l) In summary, the success of adenosine bolus cardioversion of AV nodal reentrant tachycardia appears to depend upon distance from the injection site to the heart and the presence of medications that may attenuate the patient’s sympathetic tone.