cardiac troponins are a marker of all heart muscle damage, not just myocardial infarction, which is the most severe form of heart disorder. however, diagnostic criteria for raised troponin indicating myocardial infarction is currently set by the who at a threshold of 2 μg or higher. critical levels of other cardiac biomarkers are also relevant, such as creatine kinase. other conditions that directly or indirectly lead to heart muscle damage and death can also increase troponin levels, such as kidney failure. severe tachycardia (for example due to supraventricular tachycardia) in an individual with normal coronary arteries can also lead to increased troponins for example, it is presumed due to increased oxygen demand and inadequate supply to the heart muscle.