We analyzed the morphologies and cycle lengths (CL) of ventricular tachycardia (VT) induced via noninvasive programmed stimulation vs. spontaneous VT using local bipolar intracardiac electrograms (IEGM) retrieved from 36 pts with Ventritex Cadence(R) implantable cardioverter-defibrillators, coronary disease, sustained VT/cardiac arrest, and mean EF 31.8 +/- 14.0%. A single VT IEGM morphology was induced in 15 (41.7%) pts; 21 (58.3%) had multiple (mean 2.8 +/- 0.8) VT IEGM morphologies induced. Mean CL of induced VT was 334.8 +/- 58.8 ms; mean ICD VT detect CL was 418.0 +/- 47.8 ms. A total of 392 stored IEGMs were retrieved over 34.5 +/- 19.6 months. Mean distinct spontaneous VT IEGM morphologies per pt was 2.9 +/- 1.6. One VT IEGM morphology accounted for all spontaneous episodes in 6 (16.7%) pts. In 30 (83.3%) pts with > 1 spontaneous VT IEGM morphology, a single morphology accounted for 59.7 +/- 21.0% of all retrieved VTs. Mean maximum and minimum CL of all spontaneous VTs was 384.4 +/- 57.4 and 300.4 +/- 49.7 ms. Mean CL variability of recurrent morphologically distinct VT was 49.4 +/- 36.9 ms. In 24 (66.7%) pts, =< 1 spontaneous VT had IEGM morphology identical to an induced VT. Overall, 60.2 +/- 35.5% of retrieved VTs were morphologically identical to induced VTs. Mean CL of induced and morphologically identical spontaneous VTs were similar (349.1 +/- 62.0 vs. 353.8 +/- 45.8 ms; p = 0.71).Conclusions: (1) Most pts (83%) had =< 1 spontaneous VT IEGM morphology. (2) However, a single IEGM morphology predominated in 60% of retreived episodes in pts with =< 1 morphologically distinct VT. (3) Spontaneous VT with identical IEGM morphologies and CL as induced VT occurred in 67% of pts.