CAN LATISSIMUS DORSI MUSCLE STIMULATION BENEFIT HEART DURING TRAINING PERIOD AFTER VASCULAR DELAY?

Abstract

We hypothesized that a two-stage vascular delay procedure of the latissimus dorsi muscle (LDM) would enable LDM to provide significant cardiac assistance during the training period. In mongrel dogs (n=6), LV dysfunction was induced by intracoronary injections of latex microspheres [90±2μ diameter] and a vascular delay of the LDM were performed. After 2 weeks, CMP was performed followed by conditioning of LDM. At 5 weeks, LV function was evaluated by assessing peak aortic pressure (AoP), left ventricular pressure (LVP), LV +dP/dt, LV -dP/dt, stroke volume (SV), stroke work (SW), stroke power (SP), aortic flow (Qa). LDM assisted beats (ST) were compared to non-stimulated beats (NS). LDM assistance significantly increased pressures and flow. At 33Hz (n=6), the absolute increases were LVP (13.6 ± 1.3) mmHg, AoP (12.1 ± 2.4) mmHg, SV (2.7 ± 0.7)ml, SW (7.4 ± 1.4) gm±m, SP(72.7 ± 16.5) gm±m/sec, max LV dP/dt (294 ± 19) mmHg/sec, aortic flow (1.8 ± 0.5) l/min. LDM stimulation after a two-stage vascular delay resulted in marked increases of hemodynamics during training period.