Recovery time dispersion measured by body surface mapping: noninvasive method of assessing vulnerability to ventricular tachyarrhythmias.

To assess the significance of recovery time (RT) dispersion measured by body surface mapping, we investigated body surface RT isochrone maps of 40 patients with anterior old myocardial infarction (OMI), 40 patients with dilated cardiomyopathy (DCM), and 40 controls. Among the OMI and DCM groups, 20 patients per group had sustained ventricular tachycardia (VT). The dispersion of corrected recovery time (RTc) by Bazett's formula significantly increased in OMI patients (169 +/- 38 ms) and DCM patients (163 +/- 22 ms) compared with controls (147 +/- 10 ms) (P <.01). RTc dispersion was greater in OMI patients with sustained VT than in those without sustained VT [184 +/- 43 ms vs. 155 +/- 24 ms (P <.05)], as well as in DCM patients with sustained VT compared with those without sustained VT [170 +/- 25 ms vs. 156 +/- 17 ms (P <.05)]. The results suggest that RTc dispersion determined by body surface mapping can be useful for assessing vulnerability to sustained VT.