Prehospital management of supraventricular tachycardia in Victoria, Australia: Epidemiology and effectiveness of therapies

What Adult Electrocardiogram (ECG) Diagnoses or Findings are Most Important for Advanced Care Paramedics to Know?

Introduction: The interpretation of electrocardiograms (ECGs) is an essential competency in modern paramedicine. Although educational guidelines for paramedic ECG interpretation exist, they are broad, not evidence-based, and lack prioritization in a prehospital clinical context. We conducted this study to gain consensus among stakeholders (EMS physicians, paramedic educators, and paramedic clinicians) regarding which ECG diagnoses or findings are most important for a practising advanced care paramedic to know. 

Methods: This study was an internet-based Delphi survey. We purposefully sampled participants in pairs (physician/paramedic) from all 10 Canadian provinces. Individuals rated a previously developed comprehensive list of emergency ECG diagnoses or findings on the importance of paramedic recognition and impact on prehospital care using a 4-point Likert scale. The consensus was achieved with a minimum of 75% agreement on Likert rating for a single diagnosis or finding during survey rounds one to three. When consensus was not reached, stability was defined as a shift of individual ratings between rounds of 20% or less.

Results: All 20 participants completed the first and second rounds of the survey, and 17 (85%) completed three rounds. Overall, 32 (26.4%) of 121 potentially important ECG diagnoses or findings reached consensus, 2 (1.7%) reached stability and 87 (71.9%) reached neither consensus nor stability. Twenty-one (17.4%) diagnoses or findings were considered “Very Important”, six (4.9%) “Important”, and five (4.1%) “Minimally Important”. In the first round of the survey, the mean rating of the importance of a paramedic knowing a specific ECG diagnosis or finding was lower in the physician group than the paramedic group on 85 (72%) of 118 initial diagnoses or findings.

Conclusion: We have created a list of ECG diagnoses or findings prioritized for the prehospital context that may assist paramedic educators in focusing on educational interventions. Many ECG diagnoses or findings failed to reach consensus or stability, demonstrating potential disagreement regarding clinical expectations for ECG knowledge among paramedics or physicians.

The Epidemiology and Effectiveness of Synchronized Cardioversion in a UK Prehospital Setting: A Retrospective Cross-Sectional Study

BACKGROUND

Synchronized cardioversion is an internationally accepted standard therapy for unstable tachyarrhythmias, but it is conventionally an in-hospital physician-led intervention. Increasingly, it is being brought forward into the prehospital setting as part of a specialist paramedic scope of practice; however, very little literature exists regarding the epidemiology or efficacy in this setting.

METHODS

All patients receiving cardioversion within a United Kingdom (UK) ambulance service were identified using an electronic database. The period of inclusion was March 1, 2017 through October 31, 2020. These data were then interrogated to provide demographic, physiological, and efficacy data, and then a sub-group was created to identify those who presented with a primary arrhythmia (as opposed to post-cardiac arrest).

RESULTS

From a total of 93 patients, prehospital synchronized cardioversion successfully terminated the tachyarrhythmia in 96% of patients presenting with a primary arrhythmia (85% in the allcomers group) with a predominance towards males (82% of patients) and an average age of 67 years. Hypotension and reduced level of consciousness were the most commonly documented unstable features (84.4% and 44.4%).

CONCLUSION

Cardioversion within a paramedic-led service results in efficacy rates of 96% in patients presenting with a primary tachyarrhythmia. This is a similar efficacy rate to traditional doctor-led therapies. Demographic data show that males make up over 80% of the patient population, in keeping with previously published work across the spectrum of cardiac interventions.

In The Line of Treatment: A Systematic Review of Paroxysmal Supraventricular Tachycardia

Paroxysmal supraventricular tachycardia (PSVT) is a common tachyarrhythmia, and an electrocardiogram is the best tool for making a diagnosis. If Valsalva maneuvers and carotid sinus massage do not give positive results, then the next choice is either adenosine or calcium channel blockers. At this time, adenosine is the drug of choice of treatment. Verapamil and diltiazem are the most commonly used calcium channel blockers (CCBs). This review aimed to compare the efficacy of both drugs in the treatment of PSVT.

We utilized the databases PubMed Central and Medline by using keywords: "calcium channel blockers OR adenosine AND supraventricular tachycardia." In the end, we finalized 32 studies, including observational studies, literature reviews, systematic reviews/metanalysis, and randomized control trials. We included articles only in the English language and related to humans. Two authors completed the quality assessment and evaluation of bias according to specific guidelines. Only high-quality studies were included in this systematic review based on the cut-off score of seven or above. Calcium channel blockers have a longer half-life than adenosine and were previously used as the drug of choice in the treatment of PSVT. Calcium channel blockers are safe if given slowly; however, adenosine is safer and useful when an electrocardiogram is uncertain. We compared both drugs in certain aspects and found equal efficacy. Though safer, adenosine was found to have a higher cost and a higher probability of re-initiation arrhythmia compared to calcium channel blockers. 

Safety and efficacy of paramedic treatment of regular supraventricular tachycardia: a randomised controlled trial

INTRODUCTION

Supraventricular tachycardias (SVTs) are a common cause of acute hospital presentations. Adenosine is an effective treatment. To date, no studies have directly compared paramedic-with hospital-delivered treatment of acute SVT with adenosine.

METHOD

Randomised controlled trial comparing the treatment of SVT and discharge by paramedics with conventional emergency department (ED)-based care. Patients were excluded if they had structural heart disease or contraindication to adenosine. Discharge time, follow-up management, costs and patient satisfaction were compared.

RESULTS

Eighty-six patients were enrolled: 44 were randomised to paramedic-delivered adenosine (PARA) and 42 to conventional care (ED). Of the 37 patients in the PARA group given adenosine, the tachycardia was successfully terminated in 81%. There was a 98% correlation between the paramedics' ECG diagnosis and that of two electrophysiologists. No patients had any documented adverse events in either group. The discharge time was lower in the PARA group than in the ED group (125 min (range 55-9513) vs 222 min (range 72-26 153); p=0.01), and this treatment strategy was more cost-effective (£282 vs £423; p=0.01). The majority of patients preferred this management approach. Being treated and discharged by paramedics did not result in the patients being less likely to receive ongoing management of their arrhythmia and cardiology follow-up.

CONCLUSIONS

Patients with SVT can effectively and safely be treated with adenosine delivered by trained paramedics. Implementation of paramedic-delivered acute SVT care has the potential to reduce healthcare costs without compromising patient care.

TRIAL REGISTRATION NUMBER

NCT02216240.