The Clinical Significance Of QT Dispersion In Acute Pulmonary Embolism

ObjectiveTo compare QT dispersion measurements in acute pulmonary embolism (PE) patients and normal subjects. To observe the alteration and the clinical significance of QT dispersion (QTd or QTcd) in acute pulmonary embolism.MethodsA total of42patients with PE and30age and gender matched normal subjects were studied. Patients were divided into high-risk group and non-high-risk group according to the state on admission. QT interval was measured manually in12-lead conventional electrocardiogram within24hours on admission as well as after treatment. QT dispersion (QTd) and heart rate-corrected QT dispersion were also calculated. All patients had been followed up in-hospital course.ResultsQTd and QTcd were significantly higher in high-risk group and non-high-risk group than in the normal subjects, while the same in high-risk group and non-high-risk group(70.2±34.0ms,49.3±21.8ms,33.2±12.4ms, P<0.05, in QTd)(88.1±43.3ms,59.1±26.2ms,36.7±14.2ms, P<0.05, in QTcd). The twice electrocardiograms were separated for5.6±2.5days. There were no difference in early QTd or QTcd between the patients who died and the survivors. QTd and QTcd fell significantly from early to late ECG in survivors, but not in patients who die(54.0±33.0ms vs41.0±16.4ms P<0.05, in QTd)(67.2±40.5ms vs47.4±18.0ms P<0.05,in QTcd). Based on receiver-operator characteristic curves a QTd≥51.5ms or a QTcd≥58.1ms could predict death in-hospital course with sensitivities of63.6%and80%, specificities of81.8%and88%. Logistic regression showed that hight-risk group, the presence of right ventricular dysfunction (RVD) and QTcd after treatment above normal range were the main risk factors of death in-hospital course.Conclusion1.QTd and QTcd were higher in PE patients than in normal subjects, the server of situation on admission the higher of QTd and QTcd.2.During the process of treatment QTd and QTcd has been decreased in survivors.3. High-risk group, right ventricular dysfunction and QTcd after treatment above normal range suggested of weakness prognosis in PE.