Diagnostic Value of Electrocardiogram in Predicting Exaggerated Blood Pressure Response to Exercise Stress Testing
Introduction: It is believed that an exaggerated blood pressure response (EBPR) to exercise stress test is associated with a higher risk of cardiovascular events. It is also assumed that QT dispersion (QT-d), which was originally proposed to measure the spatial dispersion of ventricular recovery t...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Electronic Physician
2016-08-01
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| Series: | Electronic Physician |
| Subjects: | |
| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5053458/ |
| Summary: | Introduction: It is believed that an exaggerated blood pressure response (EBPR) to exercise stress test is
associated with a higher risk of cardiovascular events. It is also assumed that QT dispersion (QT-d), which was
originally proposed to measure the spatial dispersion of ventricular recovery times, may have a relationship to
cardiovascular events. The objective of this study was to examine the difference of changes in QT-d, Maxi-QT,
Mini-QT, and QT-c (corrected QT interval) of the electrocardiogram in two groups of patients with exaggerated
blood pressure responses (EBPR group) and normal responses (control group) to exercise testing. Also, the
diagnostic value of each of these criteria in the prediction of EBPR was studied.
Methods: This cross-sectional study was conducted from May 2015 to February 2016 on patients suspected of
coronary artery disease (CAD) undergoing exercise testing who had been referred to Ghaem and Imam Reza
hospitals in Mashhad (Iran). All patients underwent a treadmill exercise test with the 12-lead ECG, which was
optically scanned and digitized for analysis of QT-d, QT max, and QT min. Patients were divided into two groups
of normal and EBPR to exercise testing. QT changes of ECG were compared between the two groups, and the
diagnostic accuracy of QT variables for prediction of EBPR to exercise testing was studied. A multiple linear
regression analysis (MLR), Pearson Chi-qquare, independent samples t-test, and receiver operating characteristic
(ROC) curve were used as statistical methods in IBM SPSS version 19.
Results: Sixty patients (55% male) with a mean age of 50.48 ± 10.89 years were studied in two groups of normal
(n=30) and exaggerated blood pressure response (n=30) to exercise testing. Maximum QT and QT dispersion
were statistically different in individuals’ exaggerated blood pressure response to exercise stress test (p < 0.05).
The logistic regression analysis revealed that none of our parameters predicted the EBPR. The ROC curve
showed that 50 and 345 milliseconds for QT dispersion and Maxi-QT were the optimal cut-off points for the
prediction of EBPR.
Conclusion: It seems that Maxi-QT and QT-d may be predictors of EBPR during exercise testing. Also, a
significant difference in maxi-QT and QT-d was observed between two groups of patients with normal and EBPR
during the exercise testing |
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| ISSN: | 2008-5842 2008-5842 |