抄録
To compare the clinical utility of 2 methods in detecting late potentials (Lps), out method (K-method) and Simson's method (S-method) were used in 96 patients with or without ventricular tachycardia(VT). Indices of LPs were LP duration (LPd) in K-method, and mean voltage of the filtered vector magnitude for the last 40 ms of the QRS complex (V40) in S-method. For patients with underlying cardiac disease (UD), LPd in patients with sustained VT (s-VT; 39.4 ± 20.1 ms) was significantly longer than that in patients with nonsustained VT (ns-VT; 16.1 ± 6.6 ms) or without VT (non-VT; 13.3 ± 5.2 ms) (p<0.01), while V40 in patients with s-VT, ns-VT, and non-VT were 24.7 ± 26.4μV, 56.5 ± 31.7 μV, and 98.1 ± 75.3 μV, respectively (p<0.05>). Patients without UD had less apparent LPs in both methods. There was a significant reciprocal correlation between LPd and V40 ; LPd=(378/V40)+6.66 (r=0.89, p<0.001). The sensitivity and specificity with the highest predictive accuracy for s-VT in K-method were 50% and 100% and those in S-method were 50% and 97% respectively. In conclusion, despite many differences in these 2 methods, sensitivity and specificity were nearly equal and they were both useful to identify patients with s-VT.
