Antonio Fernós Isern (May 10, 1895 – January 19, 1974) was the first Puerto Rican cardiologist and the longest serving Resident Commissioner of Puerto Rico in the United States Congress. Early years Fernós Isern was born in San Lorenzo, Puerto Rico, and attended primary and intermediate schools in Caguas. His family moved to Bloomsburg, Pennsylvania, during his mid-year in high school. He finished his high school education in the Pennsylvania State Normal School. After completing his pre-medical training, he applied and was accepted to the College of Physicians and Surgeons of the University of Maryland, College Park and earned his doctor's degree in May 1915. Fernós Isern returned to the island and settled in the city of Caguas where he practiced medicine for two years. Between the years 1918 and 1933 he held various administrative positions in the health services of Puerto Rico. In 1918, he was the Director for the City of San Juan. From 1919 to 1921, Dr. Fernós Isern was the Under-Secretary of Health. From 1921 to 1923, he was the Director of Health in the city. From 1923 to 1929, Fernós Isern was once again Under-Secretary of Health. He was the Secretary of Health from 1930 to 1933. First Puerto Rican cardiologist In 1933, Fernós Isern resigned as health commissioner and went to New York City where he completed his residency in cardiology at Columbia University and thus became the first Puerto Rican cardiologist. Upon his later return to Puerto Rico, Fernós Isern became a professor at the Public School of Tropical Medicine of Puerto Rico. He had previously served as both assistant professor and associate professor at this institution. Political career In 1937, Fernós Isern joined Luis Muñoz Marín to organize the Partido Popular Democrático (Popular Democratic Party). In 1941, he served as the Director of Civil Defense for the San Juan Metropolitan Area. In 1942, he returned to head the Department of Health and the Administration of Public Housing, in addition to serving as Director of the War Effort Office for Puerto Rico. From 1943 to 1946, Dr. Fernós 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 Franklin Delano Roosevelt. Resident Commissioner In 1946, Jesús T. Piñero, the first Puerto Rican to serve as governor of Puerto Rico, appointed Fernós Isern as his replacement in the position