Recommendations for Blood Testing

IIaB-NRTargeted blood tests are reasonable in the evaluation of selected patients with syncope identified on the basis of clinical assessment from history, physical examination, and ECG (82).
IIbC-LDUsefulness of brain natriuretic peptide and high-sensitivity troponin measurement is uncertain in patients for whom a cardiac cause of syncope is suspected (83–86).
III: No BenefitB-NRRoutine and comprehensive laboratory testing is not useful in the evaluation of patients with syncope (87,88).