Age-corrected intraoperative tachycardia correlates with postoperative electrocardiographic alterations

The intrinsic heart rate (IHR) has been calculated by an age-dependent formula; 118.1 - 0.57 x Age (years). The aim of this study was to examine whether intraoperative tachycardia of different criteria correlates with the incidence of alterations of postoperative electrocardiograms (ECG).

One hundred and twenty-two patients who underwent elective laparotomy in general surgery were studied. Tachycardia was defined as a heart rate of either 100, 110, 120, or 130 beats per minute or more, and heart rates of 1.1, 1.2, 1.3, or 1.4 times or more of the IHR. Postoperative ECG alterations were defined as positive when (1) one or more of the first letters of Minnesota Code I, IV, and V were newly added, or (2) Q-waves extended to an adjacent lead, or (3) new ST-segment depression or elevation of 0.1 mV or more was observed at 80 ms beyond the ST-junction. Correlations between intraoperative tachycardia of different criteria and alterations in 12-h postoperative ECG were investigated.

The incidence of postoperative ECG alterations was significantly greater when the intraoperative heart rate exceeded 1.2 IHR (143 - 0.7 x Age) for 30 min and 1.3 IHR (151 - 0.7 x Age) for 5 min (P = 0.04 and P = 0.003, respectively).

Age-corrected intraoperative tachycardia showed a good correlation with the incidence of postoperative ECG alterations.