[QT dispersion in acute pulmonary embolism]

Abstract

Objective: To explore the alteration and the clinical significance of QT dispersion in acute pulmonary embolism (PE).

Methods: From May 2011 to April 2012, 42 hospitalized PE patients in Xiangya Hospital of Central South University were enrolled, and divided into a high-risk group and a non-high-risk group according to the clinic state on admission. Another 30 healthy subjects with matched age and genders were enrolled as a normal control group. QT interval was measured manually in 12- lead conventional electrocardiogram within 24 hours on admission and after the treatment. QT dispersion (QTd) and heart rate-corrected QT dispersion (QTcd) were also calculated. All patients were followed up during hospitalization, and were divided to a death group and a survival group.

Results: QTd and QTcd in the high-risk group [(70.2±34.0), (88.1±43.3) ms] and the non-high-risk group [(49.3±21.8), (59.1±26.2) ms] were significantly higher than those in the normal control group[(33.2±12.4), (36.7±14.2) ms] (P<0.05), while QTd and QTcd in the high-risk group were significantly higher than those in the non-high-risk group (P<0.05). The interval of electrocardiogram was (5.6±2.5) days between 24 hours on admission and after the treatment (ECG). QTd and QTcd were reduced significantly after the treatment in the survival group [(41.0±16.4), (47.4±18.0)ms] compared with those on admission [(54.0±33.0), (67.2±40.5)ms] (P<0.05), but the QTd and QTcd after the treatment were also significantly higher than those in the normal control group (P<0.05). There was no significant difference in the QTd and QTcd between 24 hours on admission and after the treatment in the death group (P>0.05). Logistic regression showed that high-risk of PE, right ventricular dysfunction and high QTcd after the treatment were the main risk factors of hospital death.

Conclusion: QTd and QTcd are increased in PE. PE patients with right ventricular dysfunction, high-risk of PE, and high QTcd after the treatment suggest weak prognosis.