ECG analysis after medical cardioversion in patients applicable to the emergency department with supraventricular tachicardia

Introduction and Aim: Supraventricular tachycardia (SVT) is a rhythm disorder that occurs in 35 of 100,000 people worldwide each year. The mechanisms leading to SVT are multifactorial. Atrioventricular Nodal Reentrant Tachycardia (AVNRT) is the most common type of SVT. SVT is characterized by a ventricular rate of 160 bpm or more and a regular narrow complex rhythm. Carotid sinus massage and vagatonic maneuvers are the first-line treatment modalities to terminate SVT. Patients who do not respond to these methods require a medical cardioversion option. In patients with unstable hemodynamics, the first choice of treatment is electrical cardioversion. In this study, our aim is to evaluate the ECGs after medical cardioversion in SVT patients and to examine the factors affecting the sinus pause time. Methods: Our research was carried out retrospectively between 31/03/2021- 31/03/2022, Bezmialem Vakıf University Medical Faculty Hospital Emergency Department. The data of 89 patients who came to the emergency department with SVT were analyzed. Patients with SVT detected on post-admission ECG, hemodynamically stable, unresponsive to vagal maneuvers, Glasgow Coma Scale (GCS)=15, over 18 years of age, non-pregnant, and not allergic to adenosine, diltizem or beta-blockers were included in the study. During the study, adenosine, calcium channel blockers and beta-blocker medical treatment options were applied to patients with SVT. For the study, a form was created that records the demographic information of the patients, their complaints and duration of complaints, their history, the drugs they use, their blood pressure measurements before and after the treatment, the symptoms during the treatment, the number of small squares in the defibrillator's output of the rhythm after cardioversion, and whether there is a recurrence. In the treatment of these patients, washing with 10 cc saline followed by a rapid push of adenosine, and other drugs in the form of slow push in the interval of 2-5 minutes, was applied in accordance with the guideline. Statistical significance was determined as p<0.05 for all cases. Statistical analysis was performed using the IBM SPSS for Windows v.22 (IBM, Armonk, NY, United States) statistical package. Results: The study was initiated with 140 patients who were prediagnosed as supraventricular tachycardia, palpitations, pulse abnormalities and tachycardia in Bezmialem Vakıf University Medical Faculty Hospital Emergency Department. Atrial fibrillation was found in 25 of these patients, sinus tachycardia in 20, atrial flutter in 4, multifocal atrial tachycardia in 2, SVT in 89 patients, and the study was continued with these 89 patients and the others were excluded from the study. When the demographic characteristics were examined, 44 (49.4%) of the 89 patients were female and 45 (50.6%) were male. The mean age of the patients is 51 (44.5-64.5). When the age and pause time of the patients included in the study were compared, it was found that there was a weak positive correlation with the prolongation of the pause time as the age increased (p=0.012). The mean body mass index (BMI) of the patients was 28.75 (25.90-31.73). A weak negative correlation trend was found between BMI and pause time (p=0.053). It was found that the patients included in the study showed a weak positive correlation when the duration of complaints before admission and the pause time were compared. Conclusion: In the ECG analyzes we performed after medical treatment in patients who presented to the emergency department with SVT, we found that gender, comorbidities, number of previous SVT attacks, drugs used, hemoglobin levels, and adenosine dose did not have a significant effect on the ECG. However, we consider that the pause time will increase with increasing age, and the dose of adenosine can be reduced in elderly patients. In addition, we found that pause time could be shortened in patients with high BMI. We also observed that patients with a longer duration of complaints at the time of admission had a longer pause time compared to other patients. Keywords: Supraventricular tachycardia, ECG, Pause time, Adenosine