e-Transmission of ECGs for expert consultation results in improved triage and treatment of patients with acute ischaemic chest pain by ambulance paramedics

Fig. 1. The ECG protocol for pre-hospital myocardial infarction diagnosis. The following categories are distinguished by the automated ECG analysis and interpretation: Category 1: ECG with rhythm or conduction disorders. Normally the patient is transported to a centre without facilities for PCI. If there is a strong clinical suspicion of evolving MI, the ECG will be transmitted for online interpretation by the ECG expert. Category 2: ECG shows ST elevation ≥200 µv in ≥2 adjacent anterior leads, or ≥100 µv in ≥2 non-anterior leads. The ECG meet the criteria for STEMI. Immediate revascularisation is indicated, and patients are directly transported to a PCI hospital. The ambulance staff sends an alert to the PCI hospital, and transmits the ECG for completion of the medical dossier. Category 3: ECGs that do not meet the STEMI criteria, but still show total ST deviation ≥800 µv must now be transmitted for online interpretation by the ECG expert. Category 4: Abnormal ECGs without evident acute ischaemic changes. As in Category 1, the patient is transported to a non-PCI centre. If there is a strong clinical suspicion of evolving MI, the ECG will be transmitted for online interpretation by the…

Fig. 2. Time delay between ECG transmission and percutaneous coronary intervention treatment. The results are presented as PCI (percentages) time delay (per minute) between the ECG transmission time and PCI treatment time for patients in Category 2 and the Categories 1, 3 and 4 combined. Category 1: ECG with rhythm or conduction disorders. Category 2: ECG that shows ST elevation ≥200 µv in ≥2 adjacent anterior leads, or ≥100 µv in ≥2 non-anterior leads. Category 3: ECG that shows total ST deviation ≥800 µv. Category 4: abnormal ECG, without evident acute ischaemic changes (ECG electrocardiogram, MI myocardial infarction, PCI percutaneous coronary intervention, NSTEMI non-ST-elevation myocardial infarction, STEMI ST-elevation myocardial infarction, UAP unstable angina pectoris)