Up to now, the employment of skeletal muscle ventricles (SMVs) has required a two-step operation, that is, first, the construction followed by a vascular delay and electrical conditioning, and second, the integration into circulation by a second operation. As shown previously, clenbuterol increased the power of electrically conditioned SMVs wrapped around a mock system. These clenbuterol-supported SMVs pumped successfully from construction to several months against a pressure of 60-70 mm Hg. Due to these successful former experiments, a muscular blood pump has been employed via a one-step procedure, trained within the circulation under the support of clenbuterol. It appeared to be hemodynamically relevant and is expected to become clinically practicable for the treatment of end-stage heart failure.