This Technical specification describes background principles, method design, parameters and considerations and standardized approaches for the short- and long-term real time assessment of cardiovascular (CVS)-related nanotoxicity induced by the intentional exposure of ENM (10 – 100nm) or medically important mesoscale-nanoparticles (100 – 500 nm) via intravenous administration in a controlled laboratory setting; by monitoring the changes in CVS homeostasis through the use of a radio-telemetry-spectral-echocardiography in vivo assessment protocol in a conscious and unrestrained rodent model. The current protocol aimed to detect and investigate the CVS-related nanotoxicity that is induced by the ENMs that are directly introduced into the blood circulation via intravenous route. This is applicable to the ENMs that are intended to be used as intravenously delivered therapeutic or diagnostic agents. The current protocol can be adapted for preliminary investigation of the CVS-related nanotoxicity induced by the ENMs that enters the body via other routes of administration / environmental exposure, with: i. the assumption that the blood circulation is the main route of ENM distribution to the CVS tissues in the body irrespective of the route of exposure. ii. the aim to determine the theoretical threshold blood concentration of ENM that may trigger CVS-related nanotoxicity upon the ENM exposure, and to simulate the development of CVS-related toxicity upon exposure to toxic dose of ENM (done by introducing a known amount the said ENM intravenously into the test subjects) The Technical Specification is intended to complement other international efforts that address nanomaterial toxicology by focusing on the in vivo real-time progressive protocol suited for preliminary detection of cardiovascular toxicity. It is not intended to duplicate similar efforts in other international organizations such as the Organization for Economic Cooperation and Development (OECD). If the current method shows an early indication of hazard, full-scale toxicological assessment or further tiered studies with reference to other organizations’ approaches is recommended.