Adenosine response and failure to convert paroxysmal supraventricular tachycardia in the emergency department.

BACKGROUND AND IMPORTANCE: Although adenosine is the recommended first-line therapy for patients with paroxysmal supraventricular tachycardia (SVT), it may fail to restore normal sinus rhythm. The factors associated with this failure remain unclear. OBJECTIVE: To assess the response rate to adenosine and identify the factors causing adenosine failure in the management of paroxysmal SVT. DESIGN, SETTING, AND PARTICIPANTS: This retrospective study was conducted on adult patients diagnosed with paroxysmal SVT and treated with adenosine in the emergency departments of two large tertiary hospitals between June 2015 and June 2021. OUTCOME MEASURE AND ANALYSIS: The primary outcome of the study was the patient response to adenosine, defined as the restoration of sinus rhythm documented in the patients' files. Backward-stepwise multivariate logistic regression was used to examine the predictors of adenosine failure based on the overall response to adenosine therapy. MAIN RESULTS: A total of 404 patients, with a mean age of 49 (SD 15) years and a BMI of 32 (SD 8) kg/m 2 , and treated with adenosine for paroxysmal SVT, were included. Sixty-nine percent of patients were women. The overall response rate to any adenosine dose was 86% (n = 347). The baseline heart rate did not significantly differ between adenosine responders and non-responders (179.6 ±â€…23.1 vs. 183.2 ±â€…23.4). An association was observed between the history of paroxysmal SVT and successful response to adenosine (odds ratio = 2.08; 95% confidence interval 1.05-4.11). CONCLUSION: The findings of this retrospective study suggested that the use of adenosine restored normal sinus rhythm in 86% of patients with paroxysmal SVT. Furthermore, a history of paroxysmal SVT and older age were associated with an increased chance of adenosine success.

Cardiac Safety of Clonidine and Quetiapine in Post-Cardiac Surgery Intensive Care Unit Patients.

Background: Clonidine and quetiapine are frequently used medications in the cardiac surgery intensive care unit (ICU). Objective: The purpose of this study is to assess the impact of clonidine compared to quetiapine on cardiac safety outcomes in adult cardiac surgery ICU patients. Methods: This was a single-center, retrospective observational analysis at a tertiary care, academic medical center. Results: One hundred and sixty-one cardiac surgery patients who were administered clonidine or quetiapine during their ICU stay were included between June 2015 and May 2017. The major endpoint of this study was a cardiac safety composite of bradycardia, hypotension, and QTc prolongation. Minor endpoints included ICU and hospital length of stay, and in-hospital mortality. There were 115 patients included in the clonidine arm and 46 patients in the quetiapine arm. There was no difference between groups with regard to the major endpoint (30.43% vs 33.15%; P < .8). There was a shorter ICU and hospital length of stay in the clonidine arm compared to quetiapine P < .0001. All other endpoints were not statistically significant. Conclusion: Patients who received clonidine tended to have undergone less complex procedures, be younger, and have a lower APACHE II score than patients who received quetiapine. The incidence of composite cardiac safety outcomes was not different in clonidine compared to quetiapine in cardiac surgery ICU patients.