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 Natural Gas Company Gaining on Chesapeake Energy (CHK, SWN) Share. For years, Chesapeake Energy (NYSE: CHK) has been America's second largest natural gas producer. It only trails big oil behemoth ExxonMobil (NYSE: XOM), which ascended to the top after it bought XTO Energy in 2009.