Human hantavirus cardiopulmonary syndrome (HCPS) due to Andes, sin nombre and other hantaviruses is characterized by severe pulmonary capillary leak and cardiogenic shock. Hamsters, the only animal manifesting HCPS-like disease, were instrumented with radiotelemeters that enabled ambulatory intracarotid blood pressure recording within an animal biosafety level-4 facility. Following infection with Andes virus, blood pressure and heart rate decreased slowly in a biphasic manner during the first 7 days of infection, followed by a rapid fall in pressure and rapid increase in heart rate during the 10-20 h preceding death on day 9 or 10. The preterminal narrowing of pulse pressure was consistent with a cardiogenic impairment. Heart rate variability analysis implicated increased sympathetic nervous system activity as seen in human HCPS. The hamster model of HCPS mimics not only the pulmonary capillary leak but also the hypotension characteristic of human HCPS.