Pimobendan isa calcium sensitizer and a selective inhibitor of phosphodiesterase 3 (PDE3) with positive inotropic and vasodilator effects. It has been studied for treating heart failure and cardiomyopathy, primarily for veterinary uses.
Mechanoenergetic effect of pimobendan in failing dog hearts. 
Effects of pimobendan for mitral valve regurgitation in dogs. 
Pharmacokinetics of oral pimobendan in healthy cats.