This episode's headline: Heart Beat Hype?; Battling Abortion; Never on Sunday: Blue Laws; Christmas in El Salvador. The guests include In Los Angeles: Dr. JOSEPH BOYLE, President, American Medical Association; In Louisville: Dr. LAWRENCE ALTMAN, The New York Times; In Denver: LINDA ADDISON, Anti-Blue Law Lawyer; ROBERT MacINTYRE, Pro-Blue Law Lawyer; Reports from NewsHour Correspondents: KWAME HOLMAN, in Fort Lauderdale, Florida; CHARLES KRAUSE, in El Salvador. Byline: In New York: ROBERT MacNEIL, Executive Editor; CHARLAYNE HUNTER-GAULT, Correspondent; In Washington: JUDY WOODRUFF, Correspondent