Artificial heart valve was later changed to use silicone-coated material. The first implantation of mechanical heart valve to human was performed by Dr. Hufnagel on 11 September 1952, using the valve that he developed. This event accelerated the development of other artificial heart valves. Artificial heart valve An artificial heart valve is a device implanted in the heart of a patient with valvular heart disease. When one of the four heart valves malfunctions, the medical choice may be to replace the natural valve with an artificial valve. This requires open-heart surgery. Valves are integral to the normal physiological functioning of the human heart.
Human rights in Argentina "Clarin" in 2009, Fernandez Meijide, who formed part of the 1984 truth commission, claimed that the "documented" number of Argentines killed or disappeared was closer to 9,000. The "Asemblea por los Derechos Humanos" (APDH or Permanent Assembly for Human Rights) estimated the number of disappeared as 12,261, which included "definitive disappearances" and PEN detainee survivors of the clandestine detention centres spread throughout Argentina. The total figure of official prisoners was 8,625 and of these PEN detainees 157 were killed after being released from detention. Between 1969 and 1979 left-wing guerrillas accounted for 3,249 kidnappings and murders. CONADEP also recorded 458