QT dispersion in patients with pulmonary embolism.

Background: Various ECG patterns have been associated with acute pulmonary embolism. However, there is no data regarding the association between QT interval measurements and pulmonary embolism. We aimed to investigate the association between QT dispersion and the severity of pulmonary embolism (PE).

Methods: One hundred twenty-nine pulmonary embolism patients (mean age 58 ± 16.5 years) with ECGs obtained within the first 24 hours of hospital admission were included in the study. Patients were classified into low, intermediate and high-risk groups. We retrospectively measured ECG scores; maximum and minimum corrected QT intervals (QTc(max) and QTc(min)) and corrected QT interval dispersion (QTcd) in each risk group of patients.

Results: There was an increasing ECG score through from low to high-risk PE [3 (Interquartile Range, IQR: 2), 5 (IQR: 6) and 10 (IQR: 7) p < 0.0001]. QT interval analysis showed that QTcd was higher in high-risk group than in low and intermediate-risk groups (59.5 ± 23.4, 69.2 ± 21, 95.9 ± 33.2, p <0.001 and p = 0.01, respectively). Patients who died after diagnosis had significantly higher QTcd values at baseline compared with the QTcd values of surviving patients (89.1 ± 45.5 to 65 ± 22.9, p = 0.001). The sensitivity of QTcd > 71.5 ms for prediction of mortality was 71% with a specificity of 73% (p = 0.001). We observed a strong correlation between QTcd and ECG score values (r = 0.69, p< 0.001). There was also a correlation between QTcd values and pulmonary artery pressure (PAP) (r = 0.27, p = 0.05).

Conclusion: QTcd is significantly increased in high-risk PE patients compared to intermediate and low-risk patients. In addition, QTcd is significantly correlated with ECG score and PAP.