Field identification of ST-elevation myocardial infarction (STEMI) and advanced hospital notification decreases first-medical-contact-to-balloon (FMC2B) time. A recent study in this system found that electrocardiogram (ECG) transmission following a STEMI alert was frequently unsuccessful.

Instituting weekly test ECG transmissions from paramedic units to the hospital would increase successful transmission of ECGs and decrease FMC2B and door-to-balloon (D2B) times.

This was a natural experiment of consecutive patients with field-identified STEMI transported to a single percutaneous coronary intervention (PCI)-capable hospital in a regional STEMI system before and after implementation of scheduled test ECG transmissions. In November 2014, paramedic units began weekly test transmissions. The mobile intensive care nurse (MICN) confirmed the transmission, or if not received, contacted the paramedic unit and the department’s nurse educator to identify and resolve the problem. Per system-wide protocol, paramedics transmit all ECGs with interpretation of STEMI. Receiving hospitals submit patient data to a single registry as part of ongoing system quality improvement. The frequency of successful ECG transmission and time to intervention (FMC2B and D2B times) in the 18 months following implementation was compared to the 10 months prior. Post-implementation, the time the ECG transmission was received was also collected to determine the transmission gap time (time from ECG acquisition to ECG transmission received) and the advanced notification time (time from ECG transmission received to patient arrival).

There were 388 patients with field ECG interpretations of STEMI, 131 pre-intervention and 257 post-intervention. The frequency of successful transmission post-intervention was 73% compared to 64% prior; risk difference (RD)=9%; 95% CI, 1-18%. In the post-intervention period, the median FMC2B time was 79 minutes (inter-quartile range [IQR]=68-102) versus 86 minutes (IQR=71-108) pre-intervention (P=.3) and the median D2B time was 59 minutes (IQR=44-74) versus 60 minutes (IQR=53-88) pre-intervention (P=.2). The median transmission gap was three minutes (IQR=1-8) and median advanced notification time was 16 minutes (IQR=10-25).

Implementation of weekly test ECG transmissions was associated with improvement in successful real-time transmissions from field to hospital, which provided a median advanced notification time of 16 minutes, but no decrease in FMC2B or D2B times.

D’ArcyNT, BossonN, KajiAH, BuiQT, FrenchWJ, ThomasJL, ElizarrarazY, GonzalezN, GarciaJ, NiemannJT. Weekly Checks Improve Real-Time Prehospital ECG Transmission in Suspected STEMI. Prehosp Disaster Med. 2018;33(3):245–249.

Recent studies have documented decreased time to emergency department (ED) thrombolytic therapy with the use of prehospital electrocardiography.

Is the time to ED diagnosis and treatment of acute myocardial infarction (AMI) patients with thrombolytic agents decreased by emergency medical services (EMS) transport when compared with those transported by other means (non-EMS)?

Retrospective, case-control study

The AMI patients treated with thrombolytic agents at a 34,000-visit, community hospital ED during 1992.

Review of records of patients who received thrombolytic therapy for AMI. Statistical analysis was performed using “Student's” t-test and Yates corrected Chi-square (X2).

Eighty-seven patients received thrombolytic agents for AMI during 1992; 33 arrived by ambulance, 54 arrived by other methods. There were no differences in age, gender, or time of ED arrival among these groups. Ambulance patients received standard advanced life support (ALS) care, but not a 12-lead electrocardiogram (ECG) or thrombolytic agents. Ambulance patients experienced a significantly shorter time to first ECG (12.9 ±9.1 min. versus 20.8 ±25.3 win.; p = .028) and received thrombolytic therapy sooner than did controls (56.0 ±31.5 min. versus 78.0 ±63.4 min.; p = .018). There was no difference in time from diagnosis to treatment between these groups.

Emergency medical services transport of AMI patients in this study decreased time to diagnosis and treatment and may be a confounder in studies that assess the value of field EMS interventions. Non-EMS AMI patients did not receive as rapid diagnosis and treatment, and emergency physicians should evaluate and address this issue in their departments.