The Relationship Between the Frontal QRS-T Angle and High Blood Pressure Response to Exercise

Abstract

Introduction: In this study, we compared frontal QRS-T angles between normotensive subjects with high blood pressure (BP) respons to exercise test and the control group. Methods: Patients who were scheduled for an exercise test between January 2017 and January 2022 were included in the study. The patient group consisted of people who responded to the exercise test with elevated BP, and the control group included people who responded to the exercise test with normal BP. The data in the electrocardiography device's report section was used to calculate the QRS and T-axis. The frontal QRS-T angle was identified as the absolute difference between these two axes. Results: Frontal QRS-T angles were found to be significantly higher in the patient group compared with the control group (36.09 +/- 14.51 and 20.46 +/- 8.12; p<0.001). In multivariate analysis, frontal QRS-T angles were found to be an independent predictor of higher BP response to exercise test [odds ratio: 1,189, 95% confidence interval (CI); 1,083-1,305; p<0.001]. Receiver operating characteristic curve analysis showed that the frontal QRS-T angle value predicting an excessive BP response to exercise test was 27.5 degrees with a sensitivity of 71% and a specificity of 75% (area under the curve: 0.832; 95% CI: 0.75-0.91; p<0.001). Conclusion: The frontal QRS-T angles were found to be significantly higher in the group that gave higher BP response to the exercise test compared to the control group. Patients with a high BP response to exercise test can be detected using the frontal QRS-T angle before the test.