Dr. Antonio Fernós-Isern (May 10, 1895 – January 19, 1974) born in San Lorenzo, Puerto Rico - cardiologist. Fernos-Isern was the first Puerto Rican cardiologist and its longest serving resident commissioner.

Early years
In 1933, Fernos-Isern resigned as health commissioner and went to New York, here he completed his residency in cardiology at Columbia University and so became the "first" Puerto Rican cardiologist. Upon his later return to Puerto Rico, he became a professor at the "Public School of Tropical Medicine of Puerto Rico",where he had previously served as assistant and associate professor.

First Puerto Rican cardiologist
In 1937, Fernos-Isern joined Luis Muñoz Marín organize the "Popular Democratic Party" (Partido Popular Democratico). In 1941, he served as the Director of civilian defense for the San Juan Metropolitan Area. In 1942 he returned to head the Department of Health and the Administration of Public Housing, as Director of the War Effort Office for Puerto Rico. From 1943 to 1946 Dr. Fernos-Isern was also the acting governor of Puerto Rico, during the Governorship of Rexford G. Tugwell under appointment as Permanent Acting Governor approved by president Franklyn D. Roosevelt.

Later years

List of famous Puerto Ricans