Troponin

Troponin is a protein that confers calcium sensitivity to muscle cells.

Diagnostic use

Certain subtypes of troponin (Troponin I and T) are quite specific to the heart muscle (myocardium) and are measured in blood to differentiate between unstable angina pectoris and myocardial infarction in patients with chest pain.

Conditions in which cardiac troponins can be elevated:

• Cardiac:
  • Cardiac amyloidosis
  • Cardiac contusion
  • Cardiac surgery and heart transplant
  • Defibrillation
  • Closure of atrial septal defects
  • Coronary vasospasm
  • Dilated cardiomyopathy
  • Heart failure
  • Hypertrophic cardiomyopathy
  • Myocarditis
  • Percutaneous coronary intervention
  • Radiofrequency ablation
  • Supraventricular tachycardia
• Non-cardiac:
  • Critical illness, e.g. sepsis
  • High-dose chemotherapy
  • Primary pulmonary hypertension
  • Pulmonary embolism
  • Renal failure
  • Subarachnoid hemorrhage
  • Scorpion venom
  • Stroke
  • Very heavy exercise (marathon)

Sources

• Ammann P, Pfisterer M, Fehr T, Rickli H. Raised cardiac troponins. BMJ 2004;328:1028-9.