High-frequency QRS analysis compared to conventional ST-segment analysis in patients with chest pain and normal ECG referred for exercise tolerance test

摘要

Background: The novel analysis of high-frequency QRS components (HFQRS-analysis) has been proposed in patients with chest pain (CP) and normal electrocardiography (ECG) referred for exercise tolerance test (ex-ECG). The aim of the study was to compare the diagnostic value of ex-ECG with ex-HFQRS-analysis. Methods: Patients with CP and normal ECG, troponin, and echocardiography were considered. All patients underwent ex-ECG for conventional ST-segment-analysis and ex-HFQRS-analysis. A decrease ≥ 50% of the HFQRS signal intensity recorded in at least 2 contiguous leads was considered an index of ischemia, as ST-segment depression ≥ 2 mm or ≥ 1 mm and CP on ex-ECG. Exclusion criteria were: QRS duration ≥ 120 ms and inability to exercise. End-point: The composite of coronary stenosis ≥ 70% or acute coronary syndrome, revascularization, cardiovascular death at 3-month follow-up. Results: Three-hundred thirty-seven patients were enrolled (age 60 ± 15 years). The percentage of age-adjusted maximal predicted heart rate was 89 ± 10 beat per minute and the maximal systolic blood pressure was 169 ± 23 mm Hg. Nineteen patients achieved the end-point. In multivariate analysis, both ex-ECG and ex-HFQRS were predictors of the end-point. The ex-HFQRS-analysis showed higher sensitivity (63% vs. 26%; p Conclusions: In patients with CP submitted to ex-ECG, the novel ex-HFQRS-analysis shows a valuable incremental diagnostic value over ST-segment-analysis.