Due to its unique properties multi-wall carbon nanotubes arise as a solution to different problems in the medical area. The development of conductive nanostructures is viewed as an element that allows treatment in cardiovascular disease, focused on restoring disorders in the electrical pathways. The objective of this study was to assess the cell viability in an in-vitro model of RL14 human ventricular cardiomyocytes exposed to aluminum, titanium and silver doped multi-walled carbon nanotubes (MWCNTs), which potentiate their conductive effect. The analysis by scanning electron microscopy showed CNTs of different morphologies, with structures as wide, long, coiled in the form of bamboo and with spherical ends, depending on the type of doping. It was found that cell viability of cardiomyocytes decreases with exposure to MWCNTs as the concentration of treatment was increased and the type of doping was varied.