{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,4]],"date-time":"2026-04-04T17:03:28Z","timestamp":1775322208111,"version":"3.50.1"},"reference-count":0,"publisher":"SMW Supporting Association","issue":"3132","license":[{"start":{"date-parts":[[2015,7,26]],"date-time":"2015-07-26T00:00:00Z","timestamp":1437868800000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Swiss Med Wkly"],"abstract":"<jats:p>BACKGROUND:Pulseless electrical activity (PEA)  cardiac arrest is characterised by a residual organised electrical activity. PEA  is frequently induced by reversible conditions. The mnemonic \u201c4H&amp;4T\u201d was proposed  as a reminder to assess for Hypoxia, Hypovolaemia, Hypo\/Hyperkalaemia,  Hypothermia, Thrombosis, cardiac Tamponade, Toxins, and Tension pneumothorax.  Other potential aetiologies have been identified, but their respective  probability and frequencies are unclear. The aim of this study was to analyse  the aetiologies of PEA out-of-hospital cardiac arrests and to evaluate their  relative frequencies.\n        METHODS:  This was a retrospective study based on data routinely and prospectively  collected. All adult patients with PEA as the first recorded rhythm and admitted between  2002 and 2012 to the emergency department (ED) after return of spontaneous  circulation or under resuscitation were included.\n        RESULTS: A  total of 1,866 out-of-hospital cardiac arrests were included. PEA was the first  recorded rhythm in 232 adult patients (12.4%) and 144 of these were admitted to  the ED. The mean age was 63.8 \u00b1 20.0 years, 58.3% were men. The survival rate  at 48 hours was 29%. Hypoxia (23.6%), acute coronary syndrome (12.5%) and  trauma (12.5%) were the most frequent causes. We were unable to identify a  specific cause in 17.4%. Pulmonary embolism, hypovolaemia, intoxication and hypo\/hyperkalaemia  occurred in fewer than 10% of the cases. Nonischaemic cardiac disorders and  intracranial haemorrhage occurred in 8.3% and 6.9%, respectively.\n        CONCLUSIONS:  Intracranial haemorrhage and nonischaemic cardiac disorders represent significant causes of PEA,  with a prevalence equalling or exceeding the frequency of classical 4H&amp;4T aetiologies. These conditions  are potentially accessible to simple diagnostic procedures (computed tomography  or echocardiography).<\/jats:p>","DOI":"10.4414\/smw.2015.14178","type":"journal-article","created":{"date-parts":[[2016,1,29]],"date-time":"2016-01-29T10:03:57Z","timestamp":1454061837000},"page":"w14178","source":"Crossref","is-referenced-by-count":17,"title":["Pulseless  electrical activity cardiac arrest: time to amend the mnemonic \u201c4H&amp;4T\u201d?"],"prefix":"10.57187","volume":"145","author":[{"given":"Ludovic","family":"Beun","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bertrand","family":"Yersin","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joseph","family":"Osterwalder","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pierre-Nicolas","family":"Carron","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"36756","published-online":{"date-parts":[[2015,7,26]]},"container-title":["Swiss Medical Weekly"],"original-title":[],"link":[{"URL":"https:\/\/smw.ch\/index.php\/smw\/article\/download\/2053\/2984","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/smw.ch\/index.php\/smw\/article\/download\/2053\/2985","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/smw.ch\/index.php\/smw\/article\/download\/2053\/2984","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,15]],"date-time":"2025-08-15T06:31:37Z","timestamp":1755239497000},"score":1,"resource":{"primary":{"URL":"https:\/\/smw.ch\/index.php\/smw\/article\/view\/2053"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,7,26]]},"references-count":0,"journal-issue":{"issue":"3132","published-online":{"date-parts":[[2015,7,27]]}},"URL":"https:\/\/doi.org\/10.4414\/smw.2015.14178","relation":{},"ISSN":["1424-3997"],"issn-type":[{"value":"1424-3997","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,7,26]]}}}