Early effects of right latissimus dorsi cardiomyoplasty on left ventricular function

We hypothesized that left ventricular function could be improved with cardiomyoplasty using the right latissimus dorsi.

Five dogs underwent cardiomyoplasty using the right latissimus dorsi. Left ventricular volume and pressure were measured using sonomicrometry and a micromanometer catheter, respectively. Pressure volume loops were recorded with the muscle stimulated at 1:2 and with transient caval occlusion. During stimulated beats, there were significant increases in stroke work (13.90 +/- 4.49 vs 9.78 +/- 3.81 g/m, P < .01), preload recruitable stroke work (0.766 +/- 0.110 vs 0.594 +/- 0.207 g.m-1 x m-3, P < .05), and stroke volume (15 +/- 4 vs 10 +/- 3 mL, P < .05) when compared with unstimulated beats. There were no changes in diastolic filling. This operation was done in 11 patients, with no operative deaths. Six weeks after surgery, resting left ventricular ejection fraction (LVEF) increased from 25 +/- 1.6% to 35 +/- 3% (P < .05), and left ventricular end-diastolic volume (LVEDV) decreased from 365 +/- 18 to 307 +/- 24 mL, (P < .05). Nine patients were alive at 6 months. Preoperative and 6-month LVEF and LVEDV for those 9 patients were 26 +/- 2% and 29 +/- 2% (P = NS) and 316 +/- 23 and 261 +/- 22 mL (P < .05), respectively.

Long-term studies are needed to determine if these changes will improve patient survival.