QRST Isointegral Map in Dilated Cardiomyopathy

Objective: To investigate the clinical significance of the QRST isointegral map in patients with dilated cardiomyopathy (DCM). Methods: We performed body surface mapping, signal‐averaged ECG, and 201 TI myocardial imaging in 41 patients with DCM. Using the QRST I‐sub map, we derived the two parameters of the number of lead points below −2 standards of deviation for the normal nSub value and the absolute value of the Dimin. Results: LPs were detected in 17 patients (41%). The QRST I‐sub map disclosed an abnormal negative area in most of the 41 patients. Both nSub and Dlmin values were larger in the group with LP than in the other group (P < 0.01). Significant inverse correlation was detected between the root mean square voltage in the last 40 ms (index of LP) and the Dlmin value (r =−0.435, P < 0.001). The abnormal scintigraphic patterns were classified into three groups with decreased uptake in the anteroseptal, inferoapical, and postero‐lateral regions, the localizations of which were well‐matched to the minimal points on the QRST I‐sub map (F‐G 4, G‐H 2, and I‐J 3–4, respectively). There was also a close correlation between the myocardial perfusion abnormalities and the distribution of the −2SD area on the QRST I‐sub map. Conclusion: The QRST isointegral map is useful in detecting the extent and localization of the myocardial damage in patients with DCM.