QTc and QTcd Measurements and Their Relationships with Left Ventricular Hypertrophy in Hemodialysis Patients

Editor,

We read the publication on "QTc and QTcd Measurements and Their Relationships with Left Ventricular Hypertrophy in Hemodialysis Patients", which is very interesting.¹ Alonso et al.¹ concluded that "We found that QTc interval, in contrast to QTcd, is a reproducible and reliable measure and had a weak but positive correlation with LVMi in HD patients." This report used an unmatched control group; hence, the selection bias can be expected. In fact, the hypertrophy might be expected in a hemodialysis patient who might have underlying metabolic syndrome and vascular disease.² To test the reproducibility, the repeated analysis is needed and there is a need to assess the within-run and between-run precision. In the present report, one cannot conclude that the test has a good reproducibility.