RT Journal Article SR Electronic T1 A modification to the Valsalva manoeuvre improves its effectiveness in treating supraventricular tachycardia JF Evidence Based Nursing JO Evid Based Nurs FD BMJ Publishing Group Ltd and RCN Publishing Company Ltd SP 77 OP 77 DO 10.1136/ebnurs-2016-102329 VO 19 IS 3 A1 Pstras, Leszek YR 2016 UL http://ebn.bmj.com/content/19/3/77.abstract AB