The Effectiveness of Adenosine in Treating the Acute Attacks of Supra-ventricular Tachycardia

Abstract

Background: Adenosine is a natural adenine nucleoside available endogenously that decreases heart beat by blocking atrioventricular (AV) node transiently so that extend the duration of conduction in (AV) node when injected intravenously. It has a curative value in the conversion of majority of supraventricular tachycardia (SVT) to sinus rhythm. In order to evaluate the adenosine in the management of arrhythmias we conduct this study. Objective: This study was conducted to evaluate the safety and efficacy of intravenous adenosine therapy for treatment of (SVT), to determine the optimal adenosine dose effective in (SVT), and to determine the underlying conditions affecting the effective dose. And to evaluate the effectiveness of vagal maneuvers in terminating of spontaneous SVT patients and methods: A cross-sectional study conducts in a group consist of 69 patients ranged from 23-70 years old admitted to the Coronary care unit in Azadi Teaching Hospital ,in Kirkuk city, from July 2014 to June 2016. The diagnosis of (SVT) was made by present of tachycardia which is of narrow complex with a heart beat rate greater than 140 beats/ min by 12 leads chest electrocardiography (ECG). In patients who are hemodynamically stable, vagal maneuvers were carried out initially in the form of carotid sinus massage, gag reflex and Valsalva maneuver, if this failed intravenous administration of adenosine as recommended doses were preformed. If three doses of adenosine boluses were unsuccessful to convert the arrhythmia, patients were managed with other available antiarrythmias or managed with direct electrical cardio version (DC). In unstable patients were managed with (DC). Results: Of 69 included patients, diagnosed as (SVT), M: F ratio was 1:2.1. Their age ranged from 23 years to 70 years with mean age of 57 years. Vagal maneuvers (VM) resulted in restoration of sinus rhythm (SR) in 8patients (7.6%). Out of 57 episodes of (SVT), Adenosine was effective in reverting 51 episodes of SVT to sinus rhythm (89.5%). Of those converted, 18 required a single dose (6mg) (31.6%), fifteen required one additional (12mg) dose (26.3%), and another 18 required two additional doses (81mg) (31.6%).four patients were hemo-dynamically unstable (systolic blood pressure <90 mm Hg) which required (DC). Six patients (10.5%) not responding to full adenosine dose(81mg), started treatment with other medication, 1 with verapamil, 4 with amiodarone, and1 with digoxin. All of them were successfully treated. Conclusions: Adenosine is an effective medicine in treating (SVT) in those patients in whom vagal maneuvers has unsuccessful. It demonstrates a high rate of success in terminating acute attack of SVT. A higher dose may be required in majority of patients specially