The purpose of this study to determine the prognostic value of the Selvester QRS score for perioperative myocardial injury following elective non-cardiac surgery.

This study was designed as an investigator-directed, non-commercial, observational, prospective, national, single-center study. The effect of preoperative complex ECG changes on the formation of cardiac damage will be studied. The data of the people participating in the study will be kept entirely confidential. After being informed about the study, all patients giving written informed consent will undergo preoperative evaluation. An ECG and cardiac troponin analysis will be performed to the patients who meet the eligibility. After the surgery will be completed control cardiac troponin and extensive physical examination will be performed.

Inclusion Criteria:

• Patients who undergoing elective non-cardiac surgery in the operating room
• ≥18 years old
• Interpretable preoperative ECG of the patient
• Preoperative negative high sensitive Cardiac Troponin T
• ASA I-III class
• Patients who give the informed consent

Exclusion Criteria:

• A history of myocardial infarction, coronary artery disease, PCI and revascularization
• A history of chronic renal disease, cerebrovascular incident, stroke
• ASA class IV
• Patients who do not give the informed consent
• Patients who undergoing emergency surgery
• Patients whose preoperative ECG is not interpretable
• Minor procedures to be performed outside or inside the operating room

This study will be conducted on patients aged 18-90 years who have had elective surgery (besides cardiac operations) performed by a surgeon in the operating rooms of a tertiary university hospital, whose ECG before the operation is interpretable, and whose troponin value is measured before and after the operation.