OBJECTIVES: The aim of this study was to evaluate the short-term effects of partial left ventriculectomy (PLV) on left ventricular (LV) pressure-volume (P-V) loops, wall stress, and the synchrony of LV segmental volume motions in patients with dilated cardiomyopathy. BACKGROUND: Surgical LV volume reduction is under investigation as an alternative for, or bridge to, heart transplantation for patients with end-stage dilated cardiomyopathy. METHODS: We measured P-V loops in eight patients with dilated cardiomyopathy before, during and two to five days after PLV. The conductance catheter technique was used to measure LV volume instantaneously. RESULTS: The PLV reduced end-diastolic volume (EDV) acutely from 141 ± 27 to 68 ± 16 ml/m2 (p <0.001) and to 65 ± 6 ml/m2 (p <0.001) at two to five days postoperation (post-op). Cardiac index (CI) increased from 1.5 ± 0.5 to 2.6 ± 0.6 1/min/m2 (p <0.002) and was 1.8 ± 0.3 1/min/m2 (NS) at two to five days post-op. The LV ejection fraction (EF) increased from 15 ± 8% to 35 ± 6% (p <0.001) and to 26 ± 3% (p <0.003) at two to five days post-op. Tau decreased from 54 ± 8 to 38 ± 6 ms (p <0.05) and was 38 ± 5 ms (NS) at two to five days post-op. Peak wall stress decreased from 254 ± 85 to 157 ± 49mm Hg (p <0.001) and to 184 ± 40 mm Hg (p <0.003) two to five days post-op. The synchrony of LV segmental volume changes increased from 68 ± 6% before PLV to 80 ± 7% after surgery (p <0.01) and was 73 ± 4% (NS) at two to five days post-op. The LV synchrony index and CI showed a significant (p <0.0001) correlation. CONCLUSIONS: The acute decrease in LV volume in heart-failure patients following PLV resulted at short-term in unchanged SV, increases in LVEF, and decreases in peak wall stress. The increase in LV synchrony with PLV suggests that the transition to a more uniform LV contraction and relaxation pattern might be a rationale of the working mechanism of PLV. (C) 2000 by the American College of Cardiology.
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