ORIGINAL RESEARCH Prehospital management of supraventricular tachycardia in Victoria, Australia: Epidemiology and effectiveness of therapies Gavin SMITH, 1 David MCD TAYLOR, 2 Amee MORGANS 3,4 and Peter CAMERON 1 1 Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia, 2 Emergency, Austin Health, Melbourne, Victoria, Australia, 3 Innovation, Policy and Research, Benetas, Melbourne, Victoria, Australia, and 4 DCEHPP, Monash University, Melbourne, Victoria, Australia Abstract Objective: The present study exam- ined patient demographics, character- istics and the effectiveness of current prehospital supraventricular tachycar- dia (SVT) management by ambulance paramedics in Victoria, Australia. Method: We conducted a retrospec- tive study of all Victorian patients at- tended by paramedics between 14 February 2012 and 13 February 2013, where SVT was the initial or final di- agnosis. Patients were excluded if SVT was not captured on ECG, incom- plete data were recorded, or SVT began after initial assessment. Data were extracted from the VACIS ® clini- cal data warehouse. Accuracy of para- medic SVT diagnosis was examined. Results: Nine hundred and thirty- three patients were enrolled, includ- ing 882 (94.5%) adults and 564 (60.5%) women. Mean adult and pae- diatric (<18 years) patient ages were 57.5 (SD 18.1) and 10.0 (SD 4.5) years, respectively. Median ambulance re- sponse time was 11.0 (IQR 8.0) min. Paramedics correctly identified SVT in 119/123 (96.7%, 95% CI: 91.5, 99.0) of adult ECG strips examined. There were 273/882 (31.0%) patients who spontaneously reverted while in para- medic care. Valsalva manoeuvre was undertaken by 212/882 (24.0%) pa- tients and reverted the SVT in 99/358 (27.7%) attempts. Verapamil was ad- ministered to 38/882 (4.3%) patients and reverted 33 (86.8%). Aramine was administered to 43/882 (4.9%) pa- tients and 35 reverted following ad- ministration (81.4%). Synchronised cardioversion (70 J) reverted four pa- tients at first attempt. Ultimately, 438 (49.7%) patients remained in SVT on arrival at hospital. Conclusion: Patient characteristics as- sociated with SVT are more likely to be middle-aged women with a history of hypertension and hypercholestero- laemia. Therapies were underutilised leading to reduced clinical guideline ef- fectiveness. Where therapies were in- stigated, reversion rates are greater than previously reported. Key words: epidemiology, prehospital, supraventricular tachycardia, Valsalva manoeuvre, verapamil. Introduction Patients with episodic supraventricular tachycardia (SVT) have been treated in the prehospital setting globally for over four decades, employing accept- ed medical therapies in a variety of combinations according to local clini- cal governance. The rationale for treat- ment is early arrhythmia termination, despite an absence of evidence sug- gesting harm from prolonged epi- sodes (except where haemodynamic collapse occurs as a consequence of the arrhythmia). The clinical management of pa- tients with SVT by paramedics in Aus- tralia varies considerably across the States and Territories. 1–5 Treatment of SVT within Australian Ambulance Clinical Practice Guidelines (CPG) is patient perfusion dependent, with dis- tinctions made between haemodynamic stability and instability. The SVT clinical guidelines of each Australian ambulance service com- prise three therapeutic interventions aimed at achieving reversion to sinus rhythm. 1–5 These include the Valsalva manoeuvre (VM), pharmacological agents (verapamil, aramine or adeno- sine) and synchronised cardioversion (DCR). The use of DCR is reserved for those patients with poor or rapidly de- teriorating perfusion. In Victoria, aramine is used to restore perfusion in hypotensive SVT patients to enable Correspondence: Mr Gavin Smith, Epidemiology and Preventive Medicine, Monash Uni- versity, Melbourne, VIC 3000, Australia. Email: gavin.smith@monash.edu Gavin Smith, MEH, PhD Candidate, MICA Paramedic (Clinical Instructor); David McD Taylor, MD, MPH, DRCOG, FACEM, Director; Amee Morgans, BA (Psychology/ Psychophysiology), BAppSci (Hons), PhD, Innovation, Policy and Research Manager; Peter Cameron, MBBS, MD, FACEM, Director. Accepted 30 April 2014 Key findings • Patients are most likely to be female, with a his- tory of hypertension and hypercholesterolaemia. • Therapies are currently un- derutilised, leading to reduced CPG effectiveness. • Where therapies are instigated, prehospital reversion rates are higher than previously reported. Emergency Medicine Australasia (2014) 26, 350–355 doi: 10.1111/1742-6723.12248 © 2014 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine