Possible Clues:

• Angiogram sight
• It comes straight from the heart
• I-5 through Los Angeles, e.g.
• Brief article on English railway as a means of communication
• Turnpike, e.g.
• Blood vessel; important route
• Life support vessel
• Ventricle's outlet
• Big highway
• Main line of railway following a route that avoids centre of Slough