Successful conversion of unstable supraventricular tachycardia to sinus rhythm with adenosine.

STUDY PURPOSE

To evaluate the efficacy of adenosine in the treatment of emergency department patients with unstable paroxysmal supraventricular tachycardia (PSVT).

DESIGN

A retrospective chart review conducted over two years.

SETTING

A university-affiliated hospital ED.

PARTICIPANTS

Patients with unstable PSVT (systolic blood pressure of less than 90 mm Hg, chest pain, pulmonary edema, and/or altered mental status) who were treated with adenosine.

INTERVENTIONS

Patients' preadenosine and postadenosine heart rates, symptoms, and blood pressure were recorded, as were complications and recurrence of PSVT. PSVT was diagnosed by surface ECG.

RESULTS

Twelve patients were identified (three men and nine women with a mean age of 47.6 years). Nine patients presented with hypotension (mean systolic blood pressure, 79 mm Hg), ten with chest pain, and six with both chest pain and hypotension. There were no patients with altered mental status or pulmonary edema. Eight patients converted to sinus rhythm with a single 6-mg bolus of adenosine; the remaining four required an additional 12-mg bolus. In all cases, chest pain and hypotension resolved within minutes of conversion to sinus rhythm. There were no clinically significant adverse effects or recurrence of PSVT during ED observation (mean, 1.8 hours). All patients responded to adenosine; none required electrical cardioversion.

CONCLUSION

In the unstable patient with PSVT, adenosine appears to be a safe and effective alternative to current advanced cardiac life support-recommended immediate electrical cardioversion.