Background: Because ST segment depression has limited diagnostic performance at exercise electrocardiography (ECG), ST segment depression/heart rate (ST/HR) hysteresis and cardiopulmonary exercise test (CPET)-derived parameters have been proposed as alternatives to diagnose exercise-induced myocardial ischemia. We compared the diagnostic performance of such parameters. Methods: We studied 56 subjects (45 men, 11 women, age 59.7±13.6 years) referred for suspected exerciseinduced myocardial ischemia with an equivocal ECG exercise test. All subjects serially underwent CPET and a myocardial single-photon emission computerized tomography (SPECT) perfusion imaging (as the gold standard for ischemia). Maximum ST depression at peak exercise (ST-max), the ST/HR hysteresis, ΔVO2/ΔWR b–b1 slope, ΔVO2/ΔWR (aa1–bb1), VO2/HR flattening duration and other CPET parameters were derived in all subjects. Results: On the basis of SPECT, 23 subjects (41%) were considered ischemic and 33 subjects (59%) non-ischemic. ST/HR hysteresis was higher (0.026 mV; 95% CI: 0.003 to 0.049 vs−0.016 mV; 95% CI:−0.031 to−0.001 mV) and ST-max was lower (−0.105 mV; 95% CI:−0.158 to−0.052 vs 0.032 mV; 95% CI:−0.001 to−0.066 mV) in ischemic vs non-ischemic subjects (P=0.004 and P=0.001, respectively). Among CPET parameters, ΔVO2/ΔWR b–b1 slope was lower (9.4±3.8) and ΔVO2/ΔWR (aa1–bb1) was higher (2.1±2.6) in ischemic vs non-ischemic subjects (11.4±2.3, P=0.005, and 1.1±1.5, P=0.001, respectively). The ST/HR hysteresis had the highest area under the curve value, better (Pb0.05) than any other parameters tested, thus showing the highest overall diagnostic performance. Conclusion: The ST/HR hysteresis is superior to CPET-derived parameters for detecting exercise-induced myocardial ischemia in patients with equivocal ECG exercise test results.
A comparison of the diagnostic performance of the ST/HR hysteresis with cardiopulmonary stress testing parameters in detecting exercise-induced myocardial ischemia
BARNABEI, LUCA;MADONNA, Rosalinda;PALMIERI, GIUSEPPE;RADICO, FRANCESCO;TATASCIORE, ALFONSO;PERRUCCI, Mauro Gianni;CORAZZINI, ALESSANDRO;DE CATERINA, Raffaele
2013-01-01
Abstract
Background: Because ST segment depression has limited diagnostic performance at exercise electrocardiography (ECG), ST segment depression/heart rate (ST/HR) hysteresis and cardiopulmonary exercise test (CPET)-derived parameters have been proposed as alternatives to diagnose exercise-induced myocardial ischemia. We compared the diagnostic performance of such parameters. Methods: We studied 56 subjects (45 men, 11 women, age 59.7±13.6 years) referred for suspected exerciseinduced myocardial ischemia with an equivocal ECG exercise test. All subjects serially underwent CPET and a myocardial single-photon emission computerized tomography (SPECT) perfusion imaging (as the gold standard for ischemia). Maximum ST depression at peak exercise (ST-max), the ST/HR hysteresis, ΔVO2/ΔWR b–b1 slope, ΔVO2/ΔWR (aa1–bb1), VO2/HR flattening duration and other CPET parameters were derived in all subjects. Results: On the basis of SPECT, 23 subjects (41%) were considered ischemic and 33 subjects (59%) non-ischemic. ST/HR hysteresis was higher (0.026 mV; 95% CI: 0.003 to 0.049 vs−0.016 mV; 95% CI:−0.031 to−0.001 mV) and ST-max was lower (−0.105 mV; 95% CI:−0.158 to−0.052 vs 0.032 mV; 95% CI:−0.001 to−0.066 mV) in ischemic vs non-ischemic subjects (P=0.004 and P=0.001, respectively). Among CPET parameters, ΔVO2/ΔWR b–b1 slope was lower (9.4±3.8) and ΔVO2/ΔWR (aa1–bb1) was higher (2.1±2.6) in ischemic vs non-ischemic subjects (11.4±2.3, P=0.005, and 1.1±1.5, P=0.001, respectively). The ST/HR hysteresis had the highest area under the curve value, better (Pb0.05) than any other parameters tested, thus showing the highest overall diagnostic performance. Conclusion: The ST/HR hysteresis is superior to CPET-derived parameters for detecting exercise-induced myocardial ischemia in patients with equivocal ECG exercise test results.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
