Atrial tachycardia is a supraventricular tachycardia (SVT) that does not require the atrioventricular (AV) junction, accessory pathways, or ventricular tissue for its initiation and maintenance.
Page Content. Northern Natural Gas Company (Northern) is a subsidiary of Berkshire Hathaway Energy based in Omaha, Nebraska and has been in business since 1930. Northern owns and operates the largest interstate natural gas pipeline system in the United States.
1 National Nuclear Corporation (later officially just NNC), a company formed by the merger of companies that built the UK's nuclear power stations; bought by AMEC in 2005.  National Numismatic Collection, a part of the National Museum of American History.