Acute Coronary Syndrome (ACS): This is the most likely diagnosis given the combination of new T wave inversion and increasing Troponin I levels. T wave inversion can indicate myocardial ischemia, and elevated Troponin I is a specific marker for myocardial injury, which are both hallmarks of ACS.

Myocarditis: Inflammation of the myocardium can cause T wave inversion and elevated Troponin levels due to myocardial damage. Clinical context, such as recent viral illness or autoimmune disorders, would support this diagnosis.
Pulmonary Embolism: A large pulmonary embolism can cause right ventricular strain, leading to T wave inversion in the anterior leads and elevated Troponin due to right ventricular microinfarction.
Cardiac Contusion: Trauma to the chest can cause direct injury to the heart, resulting in T wave inversion and elevated Troponin levels.

Aortic Dissection: Although less common, aortic dissection can cause acute coronary syndrome by involving the coronary ostia, leading to myocardial ischemia or infarction, T wave inversion, and elevated Troponin. It's a medical emergency that requires immediate intervention.
Cardiac Tamponade: Accumulation of fluid in the pericardial space can compress the heart, impairing its function. This can lead to electrocardiographic changes, including T wave inversion, and elevated Troponin due to myocardial stretch or ischemia.

Takotsubo Cardiomyopathy: Also known as stress cardiomyopathy, this condition can mimic acute coronary syndrome with T wave inversion and elevated Troponin but is caused by extreme emotional or physical stress leading to transient left ventricular dysfunction.
Hypokalemia: Severe potassium deficiency can cause T wave inversion, but it would not typically cause a significant increase in Troponin I levels unless there was associated myocardial injury.
Cocaine-Induced Cardiomyopathy: Cocaine use can cause coronary vasospasm leading to myocardial ischemia or infarction, presenting with T wave inversion and elevated Troponin levels.