Cardiac & Resuscitation, Documentation & Patient Care Reporting, Patient Care

Building the Infrastructure for the ‘EMS-to-Balloon’ Era of STEMI Treatment

For a number of years EMS organizations have transported patients suffering acute myocardial infarction with a diagnostic ECG showing ST-segment elevation directly to primary coronary intervention, thus bypassing the emergency department.1

Protocol for activating the cath lab in STEMI patients varies from one organization to another, but the primary methods used are:

  1. Utilization of automated ECG/computer interpretation of the ECG
  2. ECG transmission to the on-call cardiologist
  3. Diagnosis by trained paramedics2

However, few organizations combine all three of these methods. EMS activation of the cath lab has been proven to shorten the time from symptom onset to catheterization by almost 40%.3

Figure 1: Paramedic app screens

STEMI reporting app for EMS

The MDA Teams app allows the paramedic to call the on-call cardiologist, transmit ECGs and patient vitals securely and directly, all while recording and documenting the event.

Magen David Adom (MDA) is the Israeli national EMS organization, which also runs the Israeli Paramedics School. MDA paramedics are well trained in ECG interpretation and are able to identify ST-elevation myocardial infarction. For many years, MDA paramedics have directly activated the cath lab. Before the smartphone era, paramedics used mobile phones to orally describe the patient, symptoms and the ECG, however since smartphones are currently widely used, transmission of the ECG is possible through personal messaging applications such as WhatsApp.

This method is not without risks; the paramedic may accidentally send the wrong ECG from an earlier patient to the on-call cardiologist, or the paramedic could transmit the ECG to the wrong person, which could lead to a breach in patient confidentiality. Another problem can be taking the photo of the ECG with the phone’s camera while in a hurry transporting the patient, thus transmitting a blurry ECG.

These methods are neither effective, secure, nor documented. For a true reduction in the symptoms-to-balloon time, EMS-to-balloon time should have a secure, well documented and effective infrastructure.

In collaboration with the intensive cardiac care units, MDA has developed a mobile app for direct transmission of ECG data from paramedics in the field to the on-call cardiologist. Called MDA Teams, the app also allows the cardiologist to see the ambulance on the map during transport with the estimated time of arrival. The information available in the ambulance is transferred directly, securely and efficiently to the receiving on-call cardiologist.

Figure 2: Cardiologist app screens

STEMI reporting app for EMS

At the beginning of each shift, the on-call cardiologist activates the MDA Teams app to transfer all STEMI alert to their phone.

MDA Teams is a dedicated mobile application that enables communication between responding ambulances and MDA dispatch centers, receiving hospitals and more. The teams can request another ambulance for assistance, or for police and fire department assistance. The app also allows the initiation of a documented phone call from inside the app. With a click of a button, the initiator of the call (either the paramedic or the cardiologist) activates the dialing server, which calls both parties, thus keeping their privacy by not showing their phone numbers. Paramedics can also initiate a documented call to regional dispatch, the organization’s medical consult center, and to the different units of hospitals.

When starting their shift, the on-call cardiologist activates the MDA Teams app and indicates that he or she is on call. Then, when a mobile intensive care unit is called to a patient having a STEMI, the paramedic can choose the receiving hospital from a list of hospitals with ICCU and cath labs available. Then, the paramedic can take the ECG and send it securely through the system. The ECG is uploaded via cellular connection from the monitoring device to the patient’s file on the server. The app then sends the ECG directly from the patient’s file to the cardiologist. This makes the process fast and efficient, and eliminates the risk of the wrong ECG being transferred.

Door-to-balloon is a term that is therefore outdated for patients with STEMI who call the ambulance. EMS-to-balloon has just received the proper infrastructure to always be utilized in our response.


  1. Terkelsen C, Lassen J, Nørgaard B, et. al. Reduction of treatment delay in patients with ST-elevation myocardial infarction: Impact of pre-hospital diagnosis and direct referral to primary percutanous coronary intervention. Eur Heart J. 2005;26(8):770–777.
  2. Le May M, Dionne R, Maloney J, et. al. Diagnostic performance and potential clinical impact of advanced care paramedic interpretation of ST-segment elevation myocardial infarction in the field. CJEM. 2006;8(6):401–407.
  3. Bradley E, Roumanis S, Radford M, et. al. Achieving door-to-balloon times that meet quality guidelines: How do successful hospitals do it? J Am Coll Cardiol. 2005;46(7):1236–1241.