ECG CriteriaPaced Electrocardiogram Requiring Fast Emergent Coronary Therapy (PERFECT) Study

Inclusion Criteria: Angiogram Cohort. Patients who present 1) directly through the study site Emergency Department (ED) OR 2) as a transfer or referral patient from the ED of another institution OR 3) as a direct admission to the study site's Catheterization Laboratory by an ambulance service, who also met the following criteria: 1.Underwent urgent or emergent coronary angiography during the index presentation for suspected ischemic symptoms (including but not limited to chest pain \[CP\] and/or shortness of breath \[SOB\]) AND 2. Had a VPR ECG recorded during the index presentation prior to the angiogram AND 3. Had sufficient troponins to rule in or rule out acute myocardial injury, per the study site's institutional protocol. From this Angiogram Cohort, a group of patients will be identified who had angiographic evidence of ACO, defined as an acute lesion with TIMI flow 0 or 1 when evaluated by an experienced study-site adjudicator.

Inclusion Criteria: Angiogram Cohort. Each study site will first identify adult patients (age 18 years or older) who presented to the study site 1) directly through the study site ED OR 2) as a transfer or referral patient from the ED of another institution OR 3) as a direct admission to the study site's Catheterization Laboratory by an ambulance service, who also met the following criteria: 1. Underwent coronary angiography during the index presentation for suspected ischemic symptoms (including but not limited to CP and/or SOB AND 2. Had a VPR ECG recorded during the index presentation prior to the angiogram AND 3. Had sufficient troponins to rule in or rule out acute myocardial injury, per the study site's institutional protocol. From this Angiogram Cohort, those who had TIMI-2 or greater flow will be identified for several research questions.

Each site will select a random sample of all adult patients who present to the ED (or by ambulance directly to the Catheterization Lab) with suspected ischemic symptoms and a VPR ECG.

Each study site will randomly select 5 unique encounters for every one 1 ACO subject identified by the site. If a study site identifies no ACO subjects, they will randomly select 30 unique encounters.

Study subjects who are included as subjects in the Angiogram Cohort (data set #1, above) and who are also selected as part of the random sample (data set #2) will be identified in REDCap as subjects for analysis in both groups, but their data will be submitted only once.

The primary control group selected from this search will be all patients in this group who do not meet criteria for acute myocardial injury, as defined by 1) all troponins below the 99th percentile or 2) Peak troponin < 3x the upper limit of normal AND no rise and/or fall of > 30%.

Each site will select a random sample of all adult patients who present to the ED (or by ambulance directly to the Catheterization Lab) with suspected ischemic symptoms and a VPR ECG.

Each study site will randomly 5 unique encounters for every 1 ACO subject identified by the site. If a study site identifies no ACO subjects, they will randomly select 30 unique encounters.

Study subjects who are included as subjects in the Angiogram Cohort (data set #1, above) and who are also selected as part of the random sample (data set #2) will be identified in REDCap as subjects for analysis in both groups, but their data will be submitted only once.

The secondary control group will include patients in this group in whom Acute MI cannot be excluded because they either have at least 1 troponin > 3x the upper limit of normal or they have at least 1 troponin between 1x and 3x the ULN AND have a rise and/or fall of at least 30%.