troponin i elevation

HI . I am a 47 year old female  who following  a painful basketball  injury ( small fracture to  larynx  with minimal displacement  )  experienced  what i thought to be episodes vaso vagal syncope secondary  to pain and stress 2 days after the accident. I also had a mild degree of burning pain in my left armpit and down the inside of this arm and generally felt unwell and anxious . I went to hospital the next day . ecg was normal but my Troponin i level was mildly elevated at 0.75 . The 99th percentile limit for this test at this hospital is 0.4 (verified by my GP)  My question is can extreme stress cause this marker to be elevated without underlying cardiac disease.
Hospital seemed unconcerned as they did not mention it although they also missed the fractured larynx as they only did a plain xray. Visit to an ENT and c.t scan a week later picked it up.
My only other relevant med history is mild thyroid  failure tsh 6.91 free t3 t4 lower end  of ref range - no treatment yet.
I also smoke ( TRYING TO QUIT). Any thoughts on the Troponin mystery would be appreciated.

[kenkeith]

QUOTE: "My question is can extreme stress cause this marker to be elevated without underlying cardiac disease".

The ST segment on an EKG can have significance if it is elevated or non-elevated and can be indications of ischemia (occluded coronary vessels) or necrosis (dead heart cells).  Apparently that has been ruled out as EKG is normal.

Elevated cardiac troponin has been found in critically ill patients without a cardiac diagnosis. Critically ill patients with sepsis (toxin in the blood) often have increased troponin levels, although the reason is unclear. The elevated troponin could be related to underlying coronary artery disease, or the release of toxins in the blood (such as tumor necrosis factor, food poisoning, smoking?!, etc. ) that can injure the heart and cause increased troponin levels.  

Patients with renal failure may have elevated troponin levels,...skeletal injury. You may have had a skeletal injury.

Further testing with an echocardiogram to determine if there is  ventricular hypertrophy (left or right), the ventricular wall stress or oxygen imbalances could cause troponin elevations. Similarly, right ventricular strain and increased pulmonary vascular resistance may explain increased troponin levels in patients with acute pulmonary embolism (blood clot).

"With the current state of troponin testing, the doctor  must know the patient's history to accurately interpret results. The diagnostic and prognostic value of elevated troponin levels has strong evidence in some populations, but can be uncertain in others. Further diagnostic studies to confirm cardiac injury are indicated in at-risk patients. Rule out other causes of elevated troponin levels, especially in critically ill patients—elevated levels have been linked to increased mortality and negative patient outcomes. Finally, to correctly evaluate troponin values, you'll need to be familiar with the specific assays and normal reference ranges used in the lab where blood samples are obtained".  Medical history such as asthma and renal insufficiency, can falsely elevate troponin levels without a cardiac event.