Preliminary Report on Continuous Stimulation vs. Intermittent Stimulation of Latissimus Dorsi Muscle in Chronic Canine Model of

In dynamic cardiomyoplasty (CMP), over-utilization leads to extensive muscle damage, which may explain the observed minimal systolic assistance with latissimus dorsi muscle (LDM) stimulation. Thus, we compared intermittent to continuous stimulation in CMP. In mongrel dogs, myocardial dysfunction was induced by intracoronary microsphere injections and vascular delay of the LDM was performed. After two weeks, a standard CMP was nerfonned. LDVI was progressively conditioned using continuous stimulation (Group CS; n = 3) or intermittent stimulation (Group IS; n = 3, 10 hours on/14 hours off per day). After 9 weeks, the effects of the LDM stimulation were examined. Significant hemodynamic increases were observed in both groups with LDM stimulation. In gioup CS, LDM stimulation increased peak left ventricular systolic pressure (8.7 ± 1.4) mmHg, peak aortic systolic pressure (10.1 ± 0.5 mmHg), stroke volume (2.3 ± 1.0 ml), stroke work (5." " ± 1.6 gm-m), and peak aortic flow (1.5 ± 0.5 ml/min). In group IS. LDM stimulation increased peak left ventricular systolic pressure (19.1 ± 1.4 minHg), peak aortic systolic pressure (15.9 ± 2.2 mmHg), stroke volume (/.5 ±2.7 ml), stroke work (14.2 ± 4.4 gnvm). and peak aortic flow (5.9 ± 1.8 mi/min). However, thes