Does a Single Troponin below the 99th percentile URL Rule out Acute MI if the Chest pain is very prolonged?

A 66 y.o. male who presented for chest pain that started this AM when he woke up, and has  persisted throughout the day prompting him to call 911. He says the pain is dull in nature and located across the chest, does not radiate, that it isworse with exhalation. He denies worsening with activity or positioning.  He endorses SOB and requested to sit up. He says this has not happened to him before. He endorses cough productive of yellow sputum.  He denies any edema. Denies history of venous thromboembolism.  He endorses a 50 pack year history of smoking. He denies recent illness or recent sick contacts. He denies fevers, sweats, chills, headache, dizziness, lightheadedness.Here is his ED ECG:Artifact.  Probable LVH.  No clear evidence of OMI or ischemia or reperfusion.If this patient had brief pain that resolved, one might interpret the T-wave inversion in inferior leads as reperfusion.However, when the pain is constant for 12 hours, and persistent, one must interpret them as entirely non-diagnostic.And if the troponin is not elevated, it would prove them tonot be due to ischemia.I saw this patient and on my history, his pain had been present and constant for 12-36 hours.We did an ED bedside cardiac ultrasound, which was normal.After a single troponin returned " negative " at 8 ng/L (URL = 34 ng/L; Limit of Detection = 4 ng/L), I believed we had ruled out MI.Here is the AssessmentCBC, Chem, and dimer were all unremarkable E...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs