General Objective: to compare the diagnostic ability of Nehb 3 lead ECG and standard 12 lead ECG in patients presenting to EMS with STEMI.
Inclusion criteria:
Age ≥ 18 years ST elevation in more than 2 contiguous leads (\> 1 mV in limb leads \& V5-V6; more than 2 mm in V1-V4) Complains of chest, neck, jaw, arm, epigastric or back pain or dyspnea Patients directly transferred to the coronary care unit.
Exclusion criteria:
Unconscious patients Unwillingness to participate in the study Presence of LBBB
Protocol:
100 patients with STEMI will be included. After initial 12 leads ECG made by EMS personnel will show changes consistent with STEMI, a portable Nehb 3 leads (ECG MiniMonitor CG 5000 N) recorder will be connected to the patient. 12 leads ECG recording will be performed according to the EMS and the CCU practices, i.e: before transport, on admission, before and after reperfusion therapy (thrombolysis or PCI), during angina episodes, and every 24 hours since admission. Nehb tracing will be recorded in parallel with standard 12 leads ECG.
ECG findings of standard 12 leads ECG and Nehb 3 leads ECG will be compared for:
Presence of ST elevation (defined as presence of ST segment elevation in 2 or more contiguous leads in 12 leads ECG versus presence of ST segment elevation or depression in 1 or more leads in Nehb ECG).
Area at risk \[8\] (defined as sum of amplitudes of ST segment elevations of all leads that demonstrate this in 12 leads ECG versus sum of amplitudes of ST segment elevations of all leads in Nehb ECG)
Severity of ischemia \[8\] (defined as disappearance of S waves in leads with normally negative QRS or J point elevation over more than 50% of R wave height in leads with normally positive QRS in 12 leads versus Nehb ECG)
Time discrimination (defined as presence of ST segment elevation at any time of recording and total amount of such events by 12 leads ECG versus Nehb ECG).
