QT dispersion is not associated with sudden cardiac death or mortality in heart transplant recipients.

Background: Sudden cardiac death (SCD) has been shown to be a significant cause of death after heart transplantation. QT dispersion (QTd) is associated with SCD in several high-risk populations. We hypothesized that QTd would predict mortality and SCD in heart transplantation patients.

Methods: We examined the clinical charts and most recent electrocardiograms (ECGs) for patients who received heart transplants at Stanford University Medical Center during the period 1981-1995. QTd was measured with all 12 leads and the precordial leads. Analysis was performed by a single reader blinded to patient outcomes.

Results: A total of 346 patients who had undergone transplantation had available ECGs and known outcomes; 155 of these patients died, and 42 of these deaths were attributed to SCD. The 12-lead mean QTd was not significantly different between outcome groups: patients who survived had a 12-lead mean QTd of 58 +/- 29 milliseconds and those who died had a 12-lead mean QTd of 61 +/- 32 milliseconds (P = .57). Patients who died from SCD had a 12-lead mean QTd of 57 +/- 31 milliseconds (P = .40), and those who died of other causes had a 12-lead mean QTd of 59 +/- 34 milliseconds (P = .36 vs those who died of SCD). Similarly, the precordial-lead mean QTd did not differ significantly between the different outcome groups.

Conclusions: We found no correlation between QTd and SCD or mortality in heart transplant recipients. Until additional studies prove a positive association, QTd should not be used as a prognostic marker in these patients.