The study is a prospective multi-centre observational study to evaluate a portable magnetocardiograph device for the rule-out of acute coronary syndrome (ACS) in patients who present to the emergency department with chest pain and other symptoms consistent with ACS.

Few, if any, studies have evaluated the rule-out (R/O) of non-ST-segment elevation (NSTE) ACS which requires the sensitivity and negative predictive value (NPV) of the test to approach 100%. An alternative triage approach, utilizing a portable magnetocardiography (MCG) instrument in the emergency setting, may lead to a more accurate R/O for NSTEMI, UA, and clinically significant non-ACS coronary artery disease (CAD), in patients presenting to the ED with chest pain. MCG in the emergency setting is a new use of this non-invasive technique and may serve as an adjunctive aid that can improve cardiac triage for NSTE ACS and clinically significant CAD.This raises the research question of whether MCG may be useful for the early triage of patients with acute chest pain. In the study protocol, a clinical evaluation is defined that will assess the ability of a portable MCG instrument, using a fixed algorithm, to R/O ACS, with improved safety (i.e. << 2% false negative rate) in patients presenting to an emergency setting with chest pain.

Inclusion Criteria:

• Patient presents to the ED with chest pain syndrome of suspected cardiac origin (i.e. symptoms consistent with ACS)
• 18+ year old male or female
• Patient is willing and able to give written informed consent

Exclusion Criteria:

• ST-segment Elevation MI (STEMI)
• Clear non-ischaemic cause for symptoms (e.g. trauma)
• Haemodynamic instability on admission (e.g. BP>220mmHg systolic & >110mmHg diastolic, <80mmHg systolic & <40mmHg diastolic, HR>160bpm)
• Ventricular tachycardia or fibrillation that cannot be treated effectively
• Atrial fibrillation
• Thoracic metal implants
• Pacemaker or internal defibrillator
• Pregnancy (if after 20-week period)* or lactation
• Patient unable to lie down (i.e. supine position) or stay still on the examination bed
• Patient unable to understand the informed consent process and/or has a poor understanding of English (e.g. English-speaking relative/translator not available)
• Patient unable to comply with the requirements of the protocol

All patients that present to the ED with chest pain syndrome of suspected cardiac origin (i.e. symptoms consistent with ACS) who are in normal sinus rhythm