Effects of 6-minute walk test on the QT dispersion in patients with congestive heart failure

摘要

Objective: To investigate the clinical value of QT dispersion (QTd) and the effects of 6-minute walk test (6-MWT) mimicking the patients daily activities on QTd in patients with congestive heart failure (CHF). Methods: Twenty-eight CHF patients and 22 normal subjects participated these study, who all completed 6-MWT without developing severe arrhythmias. Before and after 6-MWT, standardized 12-lead surface ECGs were obtained to measure QTd and corrected QTd (QTcd). Results: Both before and after 6-MWT, the QTd and QTcd in CHF patients were longer than those in the controls ( P < 0. 001) , and QTd and QTcd after 6-MWT were significantly shorter than those before 6-MWT in CHF patients (P =0. 007 , and 0. 018) . There was no significant difference in the measurement in the control group. Conclusion: QTd and QTcd are longer in CHF patients than in normal subjects. Moderate exercise may improve the inhomogeneity of ventricular repolarization dispersion in CHF patients.