Prognostic importance of automated ST-segment monitoring after coronary artery bypass graft surgery.

BACKGROUND

Automated ST-segment monitors are widely used in cardiac surgery units. The purpose of this study was to determine if cardiac morbidity and mortality, after CABG surgery, are predicted by ECG ST-segment changes on automated monitors.

METHOD: One hundred patients, who underwent CABG, were included in this prospective study. ST-segment deviations were recorded by an automated ST monitor, in the ICU, for 24 h after surgery. A reversible ST depression of more than 0.1 mV or a ST elevation of more than 0.2 mV and for at least 1 min were considered as significant episodes. Adverse cardiac outcomes were defined as: myocardial infarction (MI), severe left ventricular failure, ventricular fibrillation (VF) and cardiac-related death.

RESULTS

Sixty patients (group 1) presented significant episodes of ST deviation (6+/-5 episodes per patient). Forty patients (group 2) were free from ST changes. Eight patients from group 1 had postoperative adverse cardiac outcomes: 5 MI, 2 VF and 1 cardiac-related death. Patients from group 2 were all free from adverse cardiac outcomes. Automated ST-segment analysis during the first 24 h had a positive predictive value of 13% and a negative predictive value of 100%.

CONCLUSION

Automated ST analysis is a non-invasive, sensitive and very easy-to-use monitoring system to screen patients who may develop myocardial ischemia and cardiac complications after CABG surgery.